How many professional basketball teams are there in Puerto Rico?

Puerto Rico currently has a professional league called the Puerto Rico Soccer League which was founded in 2008 and is composed of 8 teams. It also had the Puerto Rico Islanders, which played in the North American Soccer League, the second tier of the American Soccer Pyramid. The team has been defunct since 2012; however, in June 2015 a new NASL team, Puerto Rico FC, was announced.
In 2017, Puerto Rico Sol became the first women’s pro soccer club in the Caribbean.

Sports in Puerto Rico

Sports in Puerto Rico can be traced from the ceremonial competitions amongst the pre-Columbian Native Americans of the Arawak (Taíno) tribes who inhabited the island to the modern era in which sports activities consist of an organized physical activity or skill carried out with a recreational purpose for competition. One of the sports which the Taíno's played was a ball game called "Batey". The "Batey" was played in "U" shaped fields two teams; however, unlike the ball games of the modern era, the winners were treated like heroes and the losers were sacrificed.

The Spanish Conquistadores who conquered the island introduced various sports such as horse racing, cockfighting, dominoes and a game similar to "Bowling" called "Boliche". The Spaniards however did not participate in team sports.

Spain ceded Puerto Rico to the United States as a result of their defeat in the 1898 Spanish–American War. American soldiers who organized games as part of their training introduced the sport of Boxing and Basketball to the people of Puerto Rico. The sport of baseball, which was invented in the United States, was introduced to the island by a group of Puerto Ricans and Cubans who learned the sport in the United States.

Puerto Rico participates in the Olympics as an independent nation even though it is a territory of the United States. Puerto Rico has participated as such since the 1948 Summer Olympics celebrated in London. On March 2, 1917, Puerto Ricans became citizens of the United States as a result of the enactment of the Jones–Shafroth Act (Pub.L. 64–368, 39 Stat. 951) and as such Puerto Ricans who resided in the United States mainland were and still are permitted to participate and represent that country in international sports events. However, their achievements representing the United States is part of the intertwined history of sports in the United States and Puerto Rico.

The following is the list and history of the most common sports practiced in Puerto Rico and other countries and of the Puerto Ricans or people of Puerto Rican descent who have excelled in those sports locally and/or in international events as representatives of Puerto Rico or any other country.

The Taínos who inhabited Puerto Rico before the arrival of Christopher Columbus in 1492, played a series of games which were both ceremonial and diversional, such as races, contests involving body strength and fishing. However, the two most important of these sports were the simulated warrior fights (similar to the gladiators) and ball playing. The ball game was played in a field, which they called "Batey", situated in the middle of the village. The fields were either shaped like a triangle or like a "U". The ball was made of vegetable leaves, which gave it flexibility. Two teams played against each other. The objective of the game was to keep the ball in constant motion. The players were allowed to use their heads, elbows, shoulders and knees. The team would lose a point, if for any reason the ball stopped moving. The score was kept with a mark on the ground and the game would end after the losing team received a certain amount of points. The winners were treated like heroes and the losers were sacrificed. The game had changed by the time the first Spanish settlers arrived. According to Fray Bartolomé de las Casas the game was played in the following manner: "One team served the ball and the other team returned it, using anything but the hands. If the ball arrived at shoulder height, it was returned like lightning. When it came in near the ground, the player rapidly hit the ground, striking the ball with his buttocks. Play continued from side to side until an error was made." In 1975, archaeologists from the Guaynia Society of Archeology and History at the Catholic University of Puerto Rico, members of the Archeological Society of the Southwest announced the discovery of the ruins of a "Batey" in an area called Tibes, on the outskirts of the city of Ponce. A total of 9 ball fields were discovered under thick forest overgrowth dating back to AD 25 in the area which is now known as "Centro Ceremonial Indigena de Tibes" (The Tibes Indigenoius Ceremonial Center). The site is now a tourist attraction and is open to the public. Artifacts found on the site are on display and can be seen in a museum on the site and in the Ponce Museum of Art.

The first Spaniards to inhabit the island were soldiers (Conquistadores), later they were followed by farmers, miners and their families. Team sports were virtually unheard of however, there were other types of competitions and sports in which they participated. The most common sports were horse racing, cockfighting and dominoes. The first horse track was built in San Juan in 1887. One of the most popular sports was "Boliche". The men would gather in the town plaza and roll a small ball made of wood with the objective of knocking down pins. "Boliche" was similar to bowling. Another popular sport was bullfighting, which was limited to the larger cities of Ponce and San Juan.

In the late 19th century "new" sports were introduced in Puerto Rico, after Puerto Rico became an American territory when the United States defeated Spain in the Spanish–American War. Baseball, which was invented in the United States, was introduced to the island by a group of Puerto Ricans and Cubans who learned the sport in the United States. The sport was also played by the American soldiers who organized games as part of their training. Puerto Ricans were also introduced to the sports of boxing and basketball by the occupying military forces.

Puerto Rico participates in the Olympics as an independent nation but because of Puerto Ricans having American citizenship, Puerto Rican athletes have the option of representing Puerto Rico or moving to the United States, living there for 3 previous years or more and then representing that country in the games. Some Puerto Ricans, such as Gigi Fernández in tennis, have won gold medals for the U.S.

The 1948 Summer Olympics celebrated in London, was a historical one for Puerto Rico because it was the first time that the island would participate as a nation in a major international sporting event. The island's delegation consisted of only three members, two of which finished among the ten best in pole vault. In their regional participations, the Puerto Ricans had carried the United States flag into the games. The United States protested, claiming that two nations could not use the same flag at the same time. The decree of Commonwealth on July 25, 1952 would give the Puerto Rican delegation a flag of their own.

In 1980, the United States boycotted the Olympic Games in Moscow, USSR. Germán Rieckehoff, who was then the president of the Puerto Rican Olympic Committee, was against the boycott because he believed that politics should not get involved with sporting events. He was, therefore, denied economic support from the local government. Rieckehoff did however, manage to send one athlete to represent Puerto Rico in boxing, Alberto Mercado, who became the only American citizen to participate in the 1980 Olympics.

In 1982, the Government of Puerto Rico, headed by then governor Carlos Romero Barceló, withheld economic support from the athletic delegation headed to Cuba, where the Central American and Caribbean Games were going to be held. The Puerto Rican Olympic Committee, under the leadership of Rieckehoff, had to appeal directly to the people for donations and were able to send the delegation. The Puerto Rican Olympic Committee is also the organization in charge of selecting the Puerto Rican athletes which represent the island in the Pan American Games and the Central American and Caribbean Games.

The 1988 Winter Olympics, officially known as the "XV Olympic Winter Games", was celebrated in Calgary, Alberta, Canada between February 13 and 28. It was the first Winter Olympics ever held in Canada. It was also the first time that a Puerto Rican team was sent to represent the island in an Olympic ski competition. No Puerto Rican had ever skied in the Olympics. The six-person Puerto Rican ski team was made up of native Puerto Ricans. They were Félix Flechas, Walter Sandza, Kevin Wilson, his sister Mary Pat Wilson and Jason Edelmann. Mary Pat Wilson is Puerto Rico’s first and only female Olympic skier. Even though the team did not do well in the competition, they were highly respected by their competitors.

Kristina Brandi represented Puerto Rico in the 2004 Summer Olympics in Athens, Greece. She became the first tennis player representing Puerto Rico to win a singles match in an Olympic when she beat Jelena Kostanić from Croatia (7–5 and 6–1). She lost in the second round to Russian Anastasia Myskina.

At the 2016 Summer Olympics in Rio de Janeiro, Monica Puig made Olympic history when she became the first person to win an Olympic gold medal for Puerto Rico by defeating Germany's Angelique Kerber in the women's singles tennis final. She became the first Puerto Rican female medalist in any sport.

The following table has a list of Puerto Ricans, including people of Puerto Rican ancestry, who won Olympic medals. It must be noted that "Puerto Ricans" is a term also used to describe a resident of the United States who was "born in Puerto Rico or who traces their family ancestry to Puerto Rico." Not all represented the island, some represented the United States. Puerto Ricans have won a total of 34 Olympic medals, 25 for the United States and 9 for Puerto Rico.
Puerto Rico debuted in the Paralympic Games on 1988. In this event, Isabel Bustamante was awarded the first medals for the delegation, winning one gold and two silver medals in athletics. In the 2000 Summer Paralympics, Alexis Pizarro became the first male athlete to win a medal for Puerto Rico, reaching bronze in athletics. Pizarro repeated this performance in the 2004 Summer Paralympics.

On August 20, 2008, David Bernier awarded the flag of Puerto Rico to Nilda Gómez, who was selected to be the flag bearer in the opening ceremonies of the 2008 Paralympics. Three athletes that registered A-marks attended the ceremony, which also included Alexis Pizarro in athletics and Julio Reguero in sailing. Puerto Rico's first medal in this edition of the Paralympics was won by Gómez, who won bronze in rifle shooting. She won bronze in the 10-meter trial, finishing with 489 points.

Puerto Rico's Special Olympics program was founded in 1970, since then it has offered services to more than a thousand athletes.

In the 2003 Special Olympics World Summer Games, Puerto Rico won 57 medals.

Puerto Rico won a total of 34 medals in the 2007 Special Olympics World Summer Games, including 7 gold, 18 silver and 9 bronze medals. Due to the team's performance, the Senate of Puerto Rico organized a ceremony where the athletes and trainers received recognitions.

Ron Rivera became the first NFL player of Puerto Rican descent when he played for the Chicago Bears in the 1980s. In 1986, Rivera also became the first NFL player of Puerto Rican descent to win a Super Bowl championship ring.

Others who have played in the NFL are O.J. Santiago of the Atlanta Falcons, Marco Rivera who now plays for the Dallas Cowboys and who in 2002 became the first Puerto Rican to play in the Pro Bowl as a member of the Green Bay Packers (the first of three appearances) and Glenn Martinez who in 2005 played for the Detroit Lions, Ken Amato who currently (2007) plays for the Tennessee Titans and Alvin Pearman who currently (2008) plays with the Jacksonville Jaguars are of Puerto Rican descent. Willie Colon who was drafted by the Pittsburgh Steelers in 2006 and won Super Bowl XLIII is also of Puerto Rican descent. Aaron Hernandez, formerly of the New England Patriots, was also of Puerto Rican descent. Victor Cruz, another player of Puerto Rican descent, plays for the New York Giants and is known for his salsa touchdown dance. While all of these players are of Puerto Rican descent, there has yet to be a Puerto Rican born NFL player.

American Football has been played in the island for many decades, dating all the way back to the installment of American military bases. Puerto Rico currently has 4 football leagues. PR Pee Wee league, for children 8-16, PRHSFL, for high school students, the newly created AFAF, for college students, and PRAFL, a semi-professional league. Although football has been in the island for so many years, it is not widely known. Many things attribute to this, for example lack of proper funding and advertising, lack of high school affiliated teams, both attributing to lack of good coaching. In July 2012, the Puerto Rico American Football Federation became a member of the International Federation of American Football.

Pee Wee Football League
This federation has 4 divisions, with areas in: Baldrich, Parque Central, University Gardens, Parkville, Ft. Buchanan, Carolina, and lastly Caguas. The league is played from January to March at "El Complejo Deportivo Roberto Clemente" in San Juan Saturday mornings. The following is a table with the years and weight distribution for each division:

PRHSFL
This league has 6 Varsity teams and 3 teams at Junior Varsity level. the league is made up of 2 schools, Antilles High School Pirates, and Commonwealth Comets, and four clubs, Carolina Blittz, Bayamón Wolfpack, University Garden Dolphins, and Parque Central Blue Wave.

AFAF
This league was founded in 2009 to rival the PRAFL and to one day be a part of local college athletics. There are four teams, Cataño Gators, San Juan Hurricanes, Carolina Blittz, and Baldrige Falcons.

PRAFL (Puerto Rico American Football League)
A semi-professional league founded in 1985, with 5 teams. The Bayamón Wolfpack, Baldrich 57 Falcons, Carolina Blitzz, Cataño Lancheros, and Fajardo Cariduros.

The Cataño Lancheros were the 2011 PRAFL Champions.

During the late 19th century Puerto Rico was to witness the introduction of organized team sports. The game of baseball was first introduced to the island by a group of Puerto Ricans and Cubans who had learned the game in the United States. At first the sport was not well received by the local press and general public, it was looked upon as a silly game. The first two baseball clubs were founded in 1897. They were the Almendares Baseball Club, owned by Francisco Alamo Armas and the Borinquen Baseball Club owned by Santos Filippi.

According to the daily newspaper "El País", on January 11, 1898, the first organized baseball game was played in Puerto Rico at the old velodrome which was located at the Pda.15 in Santurce, San Juan. The Borinquen team beat the Almendares with a score of 3 to 0. The first game to go a complete nine innings was played on January 30, 1898 and the Borinquen once again beat the Almendares with a score of 9 to 3.

Puerto Rico became an American territory when the United States defeated Spain in the Spanish–American War. The American soldiers stationed in Puerto Rico were permitted to organize a baseball club to play against the local clubs as diversional outlet. On November 4, 1900 the Almendares Baseball Club composed of Puerto Ricans and Cubans beat the American Baseball Club of the Second Regiment of Infantry with a score of 32 to 18. In the early 1920s, teams from Puerto Rico, such as the San Juan Stars, would travel to New York City and play against some of teams there which included teams made up of Puerto Ricans who lived there.

Modern era

Puerto Rico has over 100 Major League Baseball players who are currently active, in addition to the hundreds others who have participated in the past. These facts combine to make baseball one of the most popular sports in the island.

Some of the most notable baseball players from Puerto Rico are five Hall of Famers Roberto Clemente, Orlando Cepeda, Roberto Alomar, Iván "Pudge" Rodríguez and Edgar Martinez. Another baseball player who is a Hall of Famer and who was born to a Puerto Rican father is Reginald Martinez "Reggie" Jackson. Also amongst the notable players or former players are Jose "Cheo" Cruz, Juan González, Victor Pellot, Jorge Posada and Bernie Williams.

Chronological order of major eventsPuerto Rico has a winter baseball league named the Puerto Rico Baseball League that has operated since the early 20th century. The champion of the Puerto Rico league represents Puerto Rico is in the annual Caribbean World Series. It currently has six teams:
The Puerto Rico national baseball team competes in international events, including the World Baseball Classic, separately from the United States. Hiram Bithorn Stadium in San Juan has hosted first-round games in each of the first three World Baseball Classic tournaments.

The United States military government banned cockfighting and bullfighting from the island. They did, however, introduce a "new" sport called basketball. Basketball was used by the American soldiers as part of their physical training. When the soldiers played basketball, they used a plain straw basket which was cut open at both ends and placed it on the highest end of a pole. For a ball, they used a football and the game was played without any established set of rules.

In 1913, the YMCA of Puerto Rico organized the first game played using the official rules of basketball and in 1916, the YMCA organized the first basketball tournament in Puerto Rico. Teams organized in the other YMCAs in the island participated in the tournament. The first basketball organization in Puerto Rico was the San Juan Basketball League. Río Piedras and Bayamón later followed and formed their own leagues.

Basketball became a popular sport in Puerto Rico, due in part to the BSN, which has been around since the 1930s. During the early 1980s, with many games shown on television, the sport's popularity increased. There is also a women's professional league, which is affiliated to the BSN. Street basketball is also popular among Puerto Rico's youth.

Chronological order of major eventsPuerto Rico's national basketball team has reached the Olympic Games multiple times, including the 2004 Athens Olympics, where they became the first team to defeat the United States Dream Team during Olympic competition. Puerto Rico's national team has won gold medals in other international competitions.

Puerto Ricans have also been members of the Harlem Globetrotters. In 1995, Orlando Antigua, whose mother is Puerto Rican, became the first non-black in 52 years to play for the Harlem Globetrotters. In 2008, Orlando Melendez a.k.a. "El Gato" became the first Puerto Rican-born player and the second Hispanic to play for the Harlem Globetrotters.

Puerto Rico had a Bobsled team in the 1992, 1994 and 1998 Winter Olympics.

The sport of boxing was also introduced by the United States military which occupied Puerto Rico and the same as Basketball, boxing was used by the American soldiers as part of their physical training. Boxing competitions amongst the soldiers were open to the public. The first boxing match in Puerto Rico was held on January 15, 1899.

Boxing has, for many years, disputed the top spot for the Puerto Rican fan's favorite sport with Baseball and Basketball. Puerto Ricans have distinguished themselves both as amateurs and professionals. In 1917, Nero Chen became the first Puerto Rican professional boxer to gain international recognition. Puerto Rico has also been the site of many championship fights.

In 1948, boxer Juan Evangelista Venegas earned Puerto Rico's first Olympic medal, finishing his participation in London with a bronze medal that year. Subsequently, Puerto Rico has earned five more medals in Olympic boxing, including a silver one by Luis Ortiz in 1984. That silver medal is the only silver medal ever won by any Puerto Rican native at Olympic Games. Although he did not win a medal, Alberto Mercado became, in 1980, the only American citizen to actually participate in the Moscow Olympics.

There are twelve Puerto Ricans in the International Boxing Hall of Fame, they are Puerto Rico's first world champion Sixto Escobar, Wilfred Benítez, Wilfredo Gómez, Carlos Ortíz, Edwin Rosario, Pedro Montañez, José Chegui Torres, Joe Cortez (referee), Herbert "Cocoa Kid" Hardwick, Felix "Tito" Trinidad, Hector "Macho" Camacho. and Mario Rivera Martino (writer). Benítez (The youngest champion in boxing's history) as of May 23, 1981, was the youngest three-time world champion after knocking out World Junior Middleweight champion Maurice Hope. Hardwick, was a member of the feared "Black Murderers' Row". The late Mario Rivera Martino, served Puerto Rican boxing for more than 50 years as a writer and eventual commissioner.

Other boxers from Puerto Rico which have excelled in the sport include: Carlos De Leon, Ossie Ocasio, Alfredo Escalera, Belinda Laracuente, John Ruiz who made history by becoming boxing's first Latin American world Heavyweight champion ever, after beating WBA world champ Evander Holyfield, Alex Sánchez, Samuel Serrano, Ada Vélez, who is the first Puerto Rican Women's boxing world champion and Miguel Cotto.

In 2006, Puerto Rican Miguel Santana made boxing history by becoming the fighter who waited the longest after a title bout to find out he had become a world champion boxer. The IBF recognized Santana as a world Lightweight champion 18 years after his challenge of IBF Lightweight champion Greg Haugen, who originally beat Santana by an eleventh round technical decision.

Chronological order of major events

Among the international boxers who fought in Puerto Rico in a title bout are Muhammad Ali, Roberto Durán, and Alexis Argüello. The 1970s became known in Puerto Rico as "the golden era of Borinquen's (Puerto Rico's) Boxing".

Unlike in most states of the United States, cockfighting is legal in Puerto Rico until 2018, and there are many places that draw large crowds to see bantams fighting every weekend. It is known as the Gentleman's Sport due to the common practice of wagers being a verbal contract between two individuals and may range from $1 to thousands of dollars. Across the world, Puerto Rico has been seen as the largest capital for the controversial sport, as it is incredibly popular and often televised as other sports are. Roosters are specially bred to fight, first entering the ring between one and two years of age.

In 2018, the United States announced that it would ban cockfights in all its territories, including Puerto Rico. The ban will start in 2019.

The sport of equestrianism has certain popularity in Puerto Rico, more so among members of higher classes. Puerto Rico frequently sends contestants to different international tournaments, such as the Olympics. On August 16, 2003, Mark Watringl from the town of Aguadilla, represented the United States in the Pan American Games celebrated in the Dominican Republic. There he won the "Gold Medal" with a final total of 13.66 penalties compared to the 21.87 posted by Mexico. When presented with the Gold Medal, Watring unfurled and waved the Puerto Rican Flag. This win secured a berth in the 2004 Olympic Games in Athens, Greece. Watring represented Puerto Rico in the 2004 Olympics.

Fencing in Puerto Rico has become popular ever since David "Kike" Bernier, Victor Bernier and the brothers Jonathan and Marcos Peña have won medals in the 2003 Pan American Games celebrated in the Dominican Republic.Mirthescka Escanellas was also a popular Puerto Rican fencer. She participated at the 1996 Summer Olympics in Atlanta, Georgia, among many other international events.

While golf is not very popular in Puerto Rico, there are many golf courses across the island such as the one at Club Deportivo del Oeste. The most famous Puerto Rican golfer is Juan "Chi-Chi" Rodríguez who was inducted into the World Golf Hall of Fame in 1992. Rodríguez used to put his hat over the hole whenever he made a birdie or eagle. After he heard that other golfers were complaining about his little act, he decided to try something new. Rodríguez developed his signature "toreador dance", where he would make believe that the birdie was a "bull" and that his putter was a "sword" and he would terminate the "bull". Rodríguez represented Puerto Rico on 12 World Cup teams. In 1986, he won the Hispanic Recognition Award. In 1988, he was named "Replica's Hispanic Man of the Year".

Horse Racing is a sport which was first introduced to Puerto Rico by the Conquistadores. Horse Races continue to be a very popular sport in Puerto Rico til this day. During the earlier part of the 20th. century, races were held at El Comandante race track. Since 1972, "El Nuevo Comandante" now called "Hipodromo Camarero", in Canóvanas, has been the home of Puerto Rico's Sunday horse races, and of the annual "Clasico del Caribe", a race that reunites important horses from many countries.

Famous jockeys include J. A. Garcia and U.S. Racing Hall of Fame member, Angel Cordero, Jr. Cordero is one of the leading thoroughbred horse racing jockeys of all time in terms of wins. He was the first and only Puerto Rican jockey to win all three of the American Classic Races which consist of the Kentucky Derby, Preakness Stakes and the Belmont Stakes. Two of the most famous horses in Puerto Rican history were Camarero (world record holder for consecutive wins) Bold Forbes (1976 Kentucky Derby winner) and several Clasico del Caribe winners.

Road running have long been a part of Puerto Rico's sporting tradition. Many important races are run annually in the island, including the "Maraton de San Blas" in Coamo, long considered one of the most important half marathon races in the world, and the Ponce Marathon.

The World's Best 10K (WB10K), also known as "Maratón Teodoro Moscoso", is a 10K run celebrated in San Juan, Puerto Rico every year. It is certified by the Association of International Marathons and Road Races (AIMS) and by the International Amateur Athletic Federation (IAAF). The event was also the first race transmitted live through the Internet, with audio, video and results. WB10K was ranked among the 20 most competitive races in the world. Famous marathon runners include: Jorge "Peco" González, Hunga Maldonado.

Martial arts sports, especially karate, have had a marked ascent in popularity in Puerto Rico since the 1970s, when Bruce Lee and Jackie Chan movies were very popular among Puerto Rico's youth.

Jaime Espinal won a silver medal for Puerto Rico at the 84 kg Men's freestyle category at the 2012 Summer Olympics in London, earning Puerto Rico its second ever silver medal at the Olympics, its first since boxer Luis Ortiz in 1984, and its first Olympic medal in wrestling.

Professional wrestling has enjoyed much popularity in Puerto Rico for a long time. Matches have been televised since the 1960s, and multiple, non televised matches are held each week across the island. World Wrestling Council is the main wrestling promoter in Puerto Rico.

Famous Puerto Rican wrestlers have included Barrabas, Carlos Colón and his sons, Carlito and Primo Colon, "Los Invaders", Savio Vega, WWF* Hall of Famer Pedro Morales, and "Los Super Medicos". In addition, many World Wrestling Entertainment (WWE, formerly WWF) stars, such as Randy Savage, and Ric Flair fought in Puerto Rico before. Women's wrestling has been gaining popularity in Puerto Rico since the 1990s with performers like La Tigresa, and Black Rose.

Two Puerto Ricans have been inducted into the WWE Hall of Fame. They are Pedro Morales (1995) and Carlos Colon (2014).

Sailing as a sport has picked up in popularity in Puerto Rico since the middle 1990s, under the leadership of Enrique Figueroa and his wife, Carla Malatrasi. The pair have combined to win many international medals, and they competed at the 2000 Olympic Games. Figueroa also participated at the 1992 Olympics. On February 2, 2004, Figueroa and teammate Jorge Hernández, won the Olympic Games Rolex Regatta. They were named champions by topping 29 entries in the tornado fleet. The regatta winners had their sights set on the 2004 Olympics and Paralympic Games in Athens, Greece. 503 sailors participated with a fleet of 323 boats representing 39 nations. Figueroa went to the 2004 Olympic Games and represented Puerto Rico.

The sport known as "soccer" in the United States, is also known and referred to as "Fútbol" or in the Spanish language as "balompié".

Puerto Rico has a Puerto Rico Soccer League which is sponsored by the Federación Puertorriqueña de Fútbol. Fútbol, unlike in many of the other Latin American countries, mainly because of the strong American culture influence on the Island, did not enjoy high popularity during the 20th century. But since the new millennium it has slowly increased its fan base on the island. Puerto Rico has a FIFA sponsored federation, the Federación Puertorriqueña de Fútbol and a Senior National Team which is ranked 106 by FIFA. Puerto Rico has only made it as far as the second round or regional play for a World Cup Qualifier, this was in 2008 when it beat Dominican Republic 1-0 in the first round and lost against Honduras in the second round with an aggregate score of 6-2.

The following are among the players who have played for Puerto Rico: Héctor Ramos, Alexis Rivera Curet, Andrés Cabrero. There are several other Puerto Rican players or players of Puerto Rican descent playing abroad in foreign leagues.

Women's softball has enjoyed certain popularity in Puerto Rico. The women's national softball team has won many international events and participated at many Olympics.

Lisa Fernandez has represented the United States as member of the U.S. Women's Olympic Softball Team, winning gold medals in the 1996 Olympics in Atlanta, Georgia, 2000 Olympics in Sydney, Australia and in the 2004 Olympics in Athens, Greece. She established a women's softball record when she struck out 25 members of the women's Australian Olympic Softball Team. Ivelisse Echevarría who in 2003 was inducted into the International Softball Federation Hall of Fame is also considered by many to be the greatest pitcher born in Puerto Rico. Ten Puerto Ricans have been inducted into the International Softball Federation Hall of Fame so far.

The ten Puerto Ricans in International Softball Federation Hall of Fame are: Juan Pachot, Carlos Velasquez Class of 1997; Ismael "Chavalillo" Delgado, Jorge Tanco, Alejandro "Junior" Cruz Class of 1993 and Ivelisse Echevarria, Betty Segarra, Clara Vazquez, Jose "Tuto" Agosto, Rafi Serrano Class of 2003.

Jesus "Jesse" Vassallo is considered by many to be the greatest swimmer to have been born in Puerto Rico. In 1997, he became the first and so far the only Puerto Rican to be inducted into the International Swimming Hall of Fame. He currently heads the Puerto Rico Swimming Federation.

In 1966, 17-year-old Anita Lallande set a new record in the Central American and Caribbean Games celebrated in San Juan, when she won a total of 10 gold medals.

Fernando Cañales was a 100-meter freestyle finalist in the 1978 Berlin World Championships, earning a 5th place. He was the "first" Puerto Rican swimmer to final in the World Championships. He earned 5 gold medals and 1 silver medal during the 1978 Central American Championships in Medellín, Colombia. He became the first Puerto Rican to medal in the Pan American Games by winning silver in the 100 meters free in 1979 (San Juan, Puerto Rico) and repeating that feat in 1983 (Caracas, Venezuela).

Maritza Correia, is the first black Puerto Rican woman in history to make the U.S. Olympic Swimming Team. She earned a silver medal swimming prelims of the 400m free relay at the 2004 Olympic Games celebrated in Athens, Greece.

Years after the demolition of the Escambrón Swimming Complex, San Juan Mayor Jorge Santini will open the new roofed San Juan Natatorium, developed by San Juan Sports Director María Elena Batista, herself a former Olympic Swimmer. The official opening of the San Juan Natatorium was December 15, 2006. A second natatorium is scheduled to open in time for the 2010 Central American and Caribbean Games in Mayagüez.

On May 19, 2012, Olrando Fernández, also known as "The Puerto Rican Aquaman", became the first Puerto Rican to swim across the Strait of Gibraltar.

Tennis is not very popular as a fan sport in Puerto Rico, but many Puerto Ricans practice it as a means of exercise. It should be noted, though, that the 1984 television match between Martina Navratilova and Gigi Fernández was one of the most watched events of the year in Puerto Rican television. Gigi Fernández is arguably Puerto Rico's most famous tennis player ever, having won doubles championships in Grand Slam tournaments, including Wimbledon, winning gold medals for the USA doubles team in the 1992 and 1996 Olympics, being ranked no. 1 in the world for women's doubles tournaments, and being ranked among the top 30 singles players for most of her career. She is widely considered to be one of the greatest doubles players of all time.

Kristina Brandi is the first Puerto Rican tennis player to win an Olympic tennis match representing Puerto Rico. Brandi represented Puerto Rico in the 2004 Olympics, where she beat Jelena Kostanić from Croatia (7-5 and 6-1).

Charlie Pasarell was another noted Puerto Rican Tennis player. He lost to Pancho Gonzalez in 1969, in the second longest singles match by number of games before the introduction of the tiebreaker. It took Pancho Gonzales 112 games to defeat Charlie Pasarell in the first round 22–24, 1–6, 16–14, 6–3, 11–9.

Rafael Jordan was a player that many considered had potential to become a men's professional tour champion, but he died after an automobile accident during the mid-1990s.

Monica Puig became the first person to win an Olympic Gold Medal for Puerto Rico at the 2016 Summer Olympics. She defeated Germany's Angelique Kerber in the women's singles tennis final.

Track and Field has been another sport of note in Puerto Rico. Most schools there base their field days only on track and field events. Many Puerto Rican runners, hurlers and throwers have participated at the Olympics. Famous Puerto Rican track and fielders include Rebekah Colberg and Angelita Lind.

Colberg, also known as "The Mother of Women's Sports in Puerto Rico", from 1932–1946, for fourteen consecutive years was Puerto Rico's tennis champion. In 1938, she won two gold medals at the IV Central American and Caribbean Games, celebrated in Panama, in the discus and javelin events. In 1946, when the games were celebrated in Mexico, she won a gold medal in softball. While studying for her master's degree at Columbia University, she was in the university's field hockey and lacrosse championship teams. She was also a member of the undefeated women's basketball team of the University of Mexico.

Lind, known as "The Angel of Puerto Rico", has represented the island and participated in three Central American and Caribbean Games (CAC) and won two gold medals, three silver medals and one bronze medal. She also participated in three Pan American Games and in the 1984 Olympics celebrated in Los Angeles, California.

Javier Culson made history by becoming the first Puerto Rican track and field runner in an Olympic Game, to win the bronze medal at the 2012 London Olympics. He won it in the 400 metre hurdle competition.

The Puerto Rican Volleyball Federation was founded in 1958, the first men's tournament organized was the 'Torneo Preolimpico'. The federation's first president was Jose L. Purcell. Ten years later the Women's League was established.

Long considered the dormant sport among major sports in Puerto Rico, Volleyball has enjoyed much popularity since the 1990s, both in its professional and beach volleyball versions. Puerto Rico's "Liga Superior de Voleibol" has thrived in recent years, both in the men's and women's tournaments.

In 1970, most of Puerto Rico's national women's volleyball team's members were killed when a plane that was flying them to San Juan, Puerto Rico from the Dominican Republic crashed shortly after take-off.

In 1997, debut of foreign player in Women League. The most dominated are Laura Salinas from Monterrey, Mexico, lead the Mexico national team to several international competition. The foreign player debut in Women's League in 2000.

Some of Puerto Rico's famous volleyball players are Willie De Jesus, Raúl Papaleo and Héctor Soto. Papaleo and Ramón 'Monchito' Hernández participated in 2004 Olympic Games in Athens in Beach Volleyball, first ever volleyball team in the Island Olympic history. Laura Daniela Lloreda, meanwhile, is a Puerto Rican who played in Mexico's national volleyball team.

Héctor "Picky" Soto is the first Latin American player that has led the scoring in the World Championship's history. Soto won the Best Scorer award in 2006 FIVB World Championship in Japan and 2007 FIVB World Cup in Japan. During the World Cup, he scored 43 point against Korea, in the process establishing a scoring record. Outside of his international performance, Soto has played in the professional leagues of Italy, Tunisia, Japan and Russia.

The Baloncesto Superior Nacional, which is played under FIBA rules, currently consists of 8 teams, of which the most successful have been Leones de Ponce, Atléticos de San Germán and Vaqueros de Bayamón with 14 titles each. The league has produced players that have distinguished themselves in the NBA, EuroLeague, Spain's ACB, and other tournaments throughout the world. Among them, NBA players Butch Lee, José Ortiz, Ramón Rivas, Daniel Santiago, Carlos Arroyo and José Juan Barea started their careers playing for BSN teams.

Baloncesto Superior Nacional

The Baloncesto Superior Nacional is the first tier level professional men's basketball league in Puerto Rico. It was founded in 1929 and is organized by the Puerto Rican Basketball Federation.

The league began in 1930, and is noted for having had several head coaches who went on to achieve international recognition later in their careers. Among those are Basketball Hall of Fame members Tex Winter and Red Holzman, who coached the Leones de Ponce in the 1960s, and Phil Jackson, who coached the Piratas de Quebradillas and Gallitos de Isabela in the late 1980s. Others notable coaches who have worked for BSN teams include Gene Bartow, Lou Rossini, Del Harris, P.J. Carlesimo, Bernie Bickerstaff and Herb Brown.

During the 1980s, notable players followed in the footsteps of players such as Juan "Pachin" Vicens (1959 Santiago Chile FIBA World Championship's All-Tournament Team) and Butch Lee, the first Puerto Rican and BSN player to enter the NBA. Among those are: Mario 'Quijote' Morales, Raymond Dalmau, Jose 'Piculin' Ortiz, Ramón Rivas, Jerome Mincy, Georgie Torres, Angelo Cruz, Angel Santiago, the late Federico 'Fico' Lopez, Rolando Frazer, Mario Butler, and Rubén Rodríguez, who showcased their talents to all of Puerto Rico's TV viewers and game goers.

On October 8, 2015, the BSN team owners selected Fernando Quiñones Bodea to succeed Carlos J. Beltrán as president of the league.

The BSN tournament is played under the regular FIBA basketball rules. The teams regularly play a total of four games amongst them. For the 2017, the regular season will extend to 36 games. Of the 10 participating teams, the top 8 move on to the postseason.

Aibonito
Polluelos de Aibonito (1977–2001)
Played their home games at Cancha Marron Aponte
Aguada
Conquistadores de Aguada
Aguadilla
Tiburones de Aguadilla (1970s–1998)
Played their home games at the Luis T. Diaz Coliseum
Cabo Rojo
Taínos de Cabo Rojo (1989–1993)
Played their home games at Rebekah Colberg Cabrera Coliseum

Criollos de Caguas (1976–2009)
Played their home games at Héctor Solá Besares Coliseum
Canóvanas
Indios de Canóvanas
Played their home games at Coliseo Carlos Miguel Mangual

Gigantes de Carolina (1971–2009)
Played their home games at the Guillermo Angulo Coliseum

Toritos de Cayey (2002–2004)
Played their home games at the Cayey Municipal Coliseum

Cangrejeros de Santurce (1998–2017)
Played their home games at the Roberto Clemente Coliseum

Caciques de Humacao (2005–2017)
Played their home games at the Humacao Arena

Titanes de Morovis (1977–2006)
Played their home games in the José Pepe Huyke Coliseum

Avancinos de Villalba (1996–1998)
Played their home games at the José Ibem Marrero Coliseum

Atenienses de Manatí (2014–2017)
Played their home games at the Juan Cruz Abreu Coliseum

Rubén Rodríguez established most of the early long-standing record in the BSN. He broke both the single-season points record with 810 in 1978 and the most career points record with 11,549. The current holder of the career mark is Georgie Torres, who broke it before retiring in 2001 with 15,863 points in 679 games, playing his entire career after the establishment of the three-point line. Rodríguez also holds the mark for most rebounds in a career with 6,178. He also held the single-season rebound record with 380 in 1978, which stood until Lee Benson broke it in 2008. Currently, Neftalí Rivera holds the record for most points in a game in the Baloncesto Superior Nacional when he scored 79 points on May 22, 1974. In that game he achieve the record by making 34 field goals(all of them 2-pointers as the 3-pointers where not adopted back then) and 11 free throws. In 1989, Pablo Alicea of the Gigantes de Carolina established a record for most assists in one game with 25. The record stood for over two decades until May 1, 2012, when Jonathan García of the Caciques de Humacao broke it recording 33 assists against the Brujos de Guayama. García's mark is an unofficial world record pending the approval of Guinness World Records, since there is no higher number recorded in any amateur or professional international league or in FIBA competition. During this game, the Caciques also established the team points record for a single game with 130 and for most scored during a single (10-minute) quarter with 46. The Vaqueros de Bayamón hosted the game with most assistance in the league, with 17,621 fans attending a home game against Río Piedras on September 8, 1969. This bested the previous top of 16,564 in a game between Ponce and Santurce. The Vaqueros also hold the record for most consecutive championships, winning five from 1971-75.

Last Updated July 9, 2015


When was Halley's Comet first discovered?

Halley's periodic returns have been subject to scientific investigation since the 16th century. The three apparitions from 1531 to 1682 were noted by Edmond Halley, enabling him to predict its 1759 return. Streams of vapour observed during the comet's 1835 apparition prompted astronomer Friedrich Wilhelm Bessel to propose that the jet forces of evaporating material could be great enough to significantly alter a comet's orbit.
The 1910 approach, which came into naked-eye view around 10 April and came to perihelion on 20 April, was notable for several reasons: it was the first approach of which photographs exist, and the first for which spectroscopic data were obtained. Furthermore, the comet made a relatively close approach of 0.15 AU, making it a spectacular sight. Indeed, on 19 May, Earth actually passed through the tail of the comet. One of the substances discovered in the tail by spectroscopic analysis was the toxic gas cyanogen, which led astronomer Camille Flammarion to claim that, when Earth passed through the tail, the gas "would impregnate the atmosphere and possibly snuff out all life on the planet." His pronouncement led to panicked buying of gas masks and quack "anti-comet pills" and "anti-comet umbrellas" by the public. In reality, as other astronomers were quick to point out, the gas is so diffuse that the world suffered no ill effects from the passage through the tail.

Halley's Comet

Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–76 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and the only naked-eye comet that might appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061.

Halley's returns to the inner Solar System have been observed and recorded by astronomers since at least 240 BC. Clear records of the comet's appearances were made by Chinese, Babylonian, and medieval European chroniclers, but were not recognized as reappearances of the same object at the time. The comet's periodicity was first determined in 1705 by English astronomer Edmond Halley, after whom it is now named.

During its 1986 apparition, Halley's Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and tail formation. These observations supported a number of longstanding hypotheses about comet construction, particularly Fred Whipple's "dirty snowball" model, which correctly predicted that Halley would be composed of a mixture of volatile ices—such as water, carbon dioxide, and ammonia—and dust. The missions also provided data that substantially reformed and reconfigured these ideas; for instance, it is now understood that the surface of Halley is largely composed of dusty, non-volatile materials, and that only a small portion of it is icy.

Comet Halley is commonly pronounced, rhyming with "valley", or, rhyming with "daily". Colin Ronan, one of Edmond Halley's biographers, preferred (, similar to "holly"). Spellings of Halley's name during his lifetime included "Hailey, Haley, Hayley, Halley, Hawley", and "Hawly", so its contemporary pronunciation is uncertain, but contemporary individuals with this last name appear to prefer the version that rhymes with "valley".

Halley was the first comet to be recognized as periodic. Until the Renaissance, the philosophical consensus on the nature of comets, promoted by Aristotle, was that they were disturbances in Earth's atmosphere. This idea was disproved in 1577 by Tycho Brahe, who used parallax measurements to show that comets must lie beyond the Moon. Many were still unconvinced that comets orbited the Sun, and assumed instead that they must follow straight paths through the Solar System.

In 1687, Sir Isaac Newton published his "Philosophiæ Naturalis Principia Mathematica", in which he outlined his laws of gravity and motion. His work on comets was decidedly incomplete. Although he had suspected that two comets that had appeared in succession in 1680 and 1681 were the same comet before and after passing behind the Sun (he was later found to be correct; see Newton's Comet), he was unable to completely reconcile comets into his model.

Ultimately, it was Newton's friend, editor and publisher, Edmond Halley, who, in his 1705 "Synopsis of the Astronomy of Comets", used Newton's new laws to calculate the gravitational effects of Jupiter and Saturn on cometary orbits. Having compiled a list of 24 comet observations, he calculated that the orbital elements of a second comet that had appeared in 1682 were nearly the same as those of two comets that had appeared in 1531 (observed by Petrus Apianus) and 1607 (observed by Johannes Kepler). Halley thus concluded that all three comets were, in fact, the same object returning about every 76 years, a period that has since been found to vary between 74–79 years. After a rough estimate of the perturbations the comet would sustain from the gravitational attraction of the planets, he predicted its return for 1758. While he had personally observed the comet around perihelion in September 1682, Halley died in 1742 before he could observe its predicted return.

Halley's prediction of the comet's return proved to be correct, although it was not seen until 25 December 1758, by Johann Georg Palitzsch, a German farmer and amateur astronomer. It did not pass through its perihelion until 13 March 1759, the attraction of Jupiter and Saturn having caused a retardation of 618 days. This effect was computed prior to its return (with a one-month error to 13 April) by a team of three French mathematicians, Alexis Clairaut, Joseph Lalande, and Nicole-Reine Lepaute. The confirmation of the comet's return was the first time anything other than planets had been shown to orbit the Sun. It was also one of the earliest successful tests of Newtonian physics, and a clear demonstration of its explanatory power. The comet was first named in Halley's honour by French astronomer Nicolas-Louis de Lacaille in 1759.

Some scholars have proposed that first-century Mesopotamian astronomers already had recognized Halley's Comet as periodic. This theory notes a passage in the Bavli Talmud that refers to "a star which appears once in seventy years that makes the captains of the ships err."

Researchers in 1981 attempting to calculate the past orbits of Halley by numerical integration starting from accurate observations in the seventeenth and eighteenth centuries could not produce accurate results further back than 837 due to a close approach to Earth in that year. It was necessary to use ancient Chinese comet observations to constrain their calculations.

Halley's orbital period has varied between 74–79 years since 240 BC. Its orbit around the Sun is highly elliptical, with an orbital eccentricity of 0.967 (with 0 being a circle and 1 being a parabolic trajectory). The perihelion, the point in the comet's orbit when it is nearest the Sun, is just 0.6 AU. This is between the orbits of Mercury and Venus. Its aphelion, or farthest distance from the Sun, is 35 AU (roughly the distance of Pluto). Unusual for an object in the Solar System, Halley's orbit is retrograde; it orbits the Sun in the opposite direction to the planets, or, clockwise from above the Sun's north pole. The orbit is inclined by 18° to the ecliptic, with much of it lying south of the ecliptic. (Because it is retrograde, the true inclination is 162°.) Due to the retrograde orbit, it has one of the highest velocities relative to the Earth of any object in the Solar System. The 1910 passage was at a relative velocity of 70.56 km/s (157,838 mph or 254,016 km/h). Because its orbit comes close to Earth's in two places, Halley is associated with two meteor showers: the Eta Aquariids in early May, and the Orionids in late October. Halley is the parent body to the Orionids. Observations conducted around the time of Halley's appearance in 1986 suggested that the comet could additionally perturb the Eta Aquariids meteor shower, although it might not be the parent of that shower.

Halley is classified as a "periodic" or "short-period comet"; one with an orbit lasting 200 years or less. This contrasts it with long-period comets, whose orbits last for thousands of years. Periodic comets have an average inclination to the ecliptic of only ten degrees, and an orbital period of just 6.5 years, so Halley's orbit is atypical. Most short-period comets (those with orbital periods shorter than 20 years and inclinations of 20–30 degrees or less) are called Jupiter-family comets. Those resembling Halley, with orbital periods of between 20 and 200 years and inclinations extending from zero to more than 90 degrees, are called Halley-type comets., only 75 Halley-type comets have been observed, compared with 511 identified Jupiter-family comets.

The orbits of the Halley-type comets suggest that they were originally long-period comets whose orbits were perturbed by the gravity of the giant planets and directed into the inner Solar System. If Halley was once a long-period comet, it is likely to have originated in the Oort cloud, a sphere of cometary bodies that has an inner edge of 20,000–50,000 AU. Conversely the Jupiter-family comets are generally believed to originate in the Kuiper belt, a flat disc of icy debris between 30 AU (Neptune's orbit) and 50 AU from the Sun (in the scattered disc). Another point of origin for the Halley-type comets was proposed in 2008, when a trans-Neptunian object with a retrograde orbit similar to Halley's was discovered,, whose orbit takes it from just outside that of Uranus to twice the distance of Pluto. It may be a member of a new population of small Solar System bodies that serves as the source of Halley-type comets.

Halley has probably been in its current orbit for 16,000–200,000 years, although it is not possible to numerically integrate its orbit for more than a few tens of apparitions, and close approaches before 837 AD can only be verified from recorded observations. The non-gravitational effects can be crucial; as Halley approaches the Sun, it expels jets of sublimating gas from its surface, which knock it very slightly off its orbital path. These orbital changes cause delays in its perihelion of four days, average.

In 1989, Boris Chirikov and Vitaly Vecheslavov performed an analysis of 46 apparitions of Halley's Comet taken from historical records and computer simulations. These studies showed that its dynamics were chaotic and unpredictable on long timescales. Halley's projected lifetime could be as long as 10 million years. These studies also showed that many physical properties of Halley's Comet dynamics can be approximately described by a simple symplectic map, known as the Kepler map. More recent work suggests that Halley will evaporate, or split in two, within the next few tens of thousands of years, or will be ejected from the Solar System within a few hundred thousand years. Observations by D.W. Hughes suggest that Halley's nucleus has been reduced in mass by 80 to 90% over the last 2,000 to 3,000 revolutions.

The "Giotto" and "Vega" missions gave planetary scientists their first view of Halley's surface and structure. Like all comets, as Halley nears the Sun, its volatile compounds (those with low boiling points, such as water, carbon monoxide, carbon dioxide and other ices) begin to sublime from the surface of its nucleus. This causes the comet to develop a coma, or atmosphere, up to 100,000 km across. Evaporation of this dirty ice releases dust particles, which travel with the gas away from the nucleus. Gas molecules in the coma absorb solar light and then re-radiate it at different wavelengths, a phenomenon known as fluorescence, whereas dust particles scatter the solar light. Both processes are responsible for making the coma visible. As a fraction of the gas molecules in the coma are ionized by the solar ultraviolet radiation, pressure from the solar wind, a stream of charged particles emitted by the Sun, pulls the coma's ions out into a long tail, which may extend more than 100 million kilometres into space. Changes in the flow of the solar wind can cause disconnection events, in which the tail completely breaks off from the nucleus.

Despite the vast size of its coma, Halley's nucleus is relatively small: barely 15 kilometres long, 8 kilometres wide and perhaps 8 kilometres thick. Its shape vaguely resembles that of a peanut. Its mass is relatively low (roughly 2.2 kg) and its average density is about 0.6 g/cm, indicating that it is made of a large number of small pieces, held together very loosely, forming a structure known as a rubble pile. Ground-based observations of coma brightness suggested that Halley's rotation period was about 7.4 days. Images taken by the various spacecraft, along with observations of the jets and shell, suggested a period of 52 hours. Given the irregular shape of the nucleus, Halley's rotation is likely to be complex. Although only 25% of Halley's surface was imaged in detail during the flyby missions, the images revealed an extremely varied topography, with hills, mountains, ridges, depressions, and at least one crater.

Halley is the most active of all the periodic comets, with others, such as Comet Encke and Comet Holmes, being one or two orders of magnitude less active. Its day side (the side facing the Sun) is far more active than the night side. Spacecraft observations showed that the gases ejected from the nucleus were 80% water vapour, 17% carbon monoxide and 3–4% carbon dioxide, with traces of hydrocarbons although more-recent sources give a value of 10% for carbon monoxide and also include traces of methane and ammonia. The dust particles were found to be primarily a mixture of carbon–hydrogen–oxygen–nitrogen (CHON) compounds common in the outer Solar System, and silicates, such as are found in terrestrial rocks. The dust particles decreased in size down to the limits of detection (~0.001 µm). The ratio of deuterium to hydrogen in the water released by Halley was initially thought to be similar to that found in Earth's ocean water, suggesting that Halley-type comets may have delivered water to Earth in the distant past. Subsequent observations showed Halley's deuterium ratio to be far higher than that found in Earth's oceans, making such comets unlikely sources for Earth's water.

"Giotto" provided the first evidence in support of Fred Whipple's "dirty snowball" hypothesis for comet construction; Whipple postulated that comets are icy objects warmed by the Sun as they approach the inner Solar System, causing ices on their surfaces to sublimate (change directly from a solid to a gas), and jets of volatile material to burst outward, creating the coma. "Giotto" showed that this model was broadly correct, though with modifications. Halley's albedo, for instance, is about 4%, meaning that it reflects only 4% of the sunlight hitting it; about what one would expect for coal. Thus, despite appearing brilliant white to observers on Earth, Halley's Comet is in fact pitch black. The surface temperature of evaporating "dirty ice" ranges from at higher albedo to at low albedo; Vega 1 found Halley's surface temperature to be in the range. This suggested that only 10% of Halley's surface was active, and that large portions of it were coated in a layer of dark dust that retained heat. Together, these observations suggested that Halley was in fact predominantly composed of non-volatile materials, and thus more closely resembled a "snowy dirtball" than a "dirty snowball".

Halley may have been recorded as early as 467 BC, but this is uncertain. A comet was recorded in ancient Greece between 468 and 466 BC; its timing, location, duration, and associated meteor shower all suggest it was Halley. According to Pliny the Elder, that same year a meteorite fell in the town of Aegospotami, in Thrace. He described it as brown in colour and the size of a wagon load. Chinese chroniclers also mention a comet in that year.

The first certain appearance of Halley's Comet in the historical record is a description from 240 BC, in the Chinese chronicle "Records of the Grand Historian" or "Shiji", which describes a comet that appeared in the east and moved north. The only surviving record of the 164 BC apparition is found on two fragmentary Babylonian tablets, now owned by the British Museum.

The apparition of 87 BC was recorded in Babylonian tablets which state that the comet was seen "day beyond day" for a month. This appearance may be recalled in the representation of Tigranes the Great, an Armenian king who is depicted on coins with a crown that features, according to Vahe Gurzadyan and R. Vardanyan, "a star with a curved tail [that] may represent the passage of Halley's Comet in 87 BC." Gurzadyan and Vardanyan argue that "Tigranes could have seen Halley's Comet when it passed closest to the Sun on August 6 in 87 BC" as the comet would have been a "most recordable event"; for ancient Armenians it could have heralded the New Era of the brilliant King of Kings.

The apparition of 12 BC was recorded in the "Book of Han" by Chinese astronomers of the Han Dynasty who tracked it from August through October. It passed within 0.16 AU of Earth. According to the Roman historian Cassius Dio, a comet appeared suspended over Rome for several days portending the death of Marcus Vipsanius Agrippa in that year. Halley's appearance in 12 BC, only a few years distant from the conventionally assigned date of the birth of Jesus Christ, has led some theologians and astronomers to suggest that it might explain the biblical story of the Star of Bethlehem. There are other explanations for the phenomenon, such as planetary conjunctions, and there are also records of other comets that appeared closer to the date of Jesus' birth.

If, as has been suggested, the reference in the Talmud to "a star which appears once in seventy years that makes the captains of the ships err" (see above) refers to Halley's Comet, it may be a reference to the 66 AD appearance, because this passage is attributed to the Rabbi Yehoshua ben Hananiah. This apparition was the only one to occur during ben Hananiah's lifetime.

The 141 AD apparition was recorded in Chinese chronicles. It was also recorded in the Tamil work "Purananuru", in connection with the death of the south Indian Chera king Yanaikatchai Mantaran Cheral Irumporai.

The 374 AD and 607 approaches each came within 0.09 AU of Earth. The 684 AD apparition was recorded in Europe in one of the sources used by the compiler of the 1493 Nuremberg Chronicles; it is the oldest-known picture of a comet. Chinese records also report it as the "broom star". The 451 AD apparition was said to herald the defeat of Attila the Hun at the Battle of Chalons.
In 837, Halley's Comet may have passed as close as 0.03 AU (3.2 million miles; 5.1 million kilometres) from Earth, by far its closest approach. Its tail may have stretched 60 degrees across the sky. It was recorded by astronomers in China, Japan, Germany, the Byzantine Empire, and the Middle East. In 912, Halley is recorded in the "Annals of Ulster", which state "A dark and rainy year. A comet appeared."

In 1066, the comet was seen in England and thought to be an omen: later that year Harold II of England died at the Battle of Hastings; it was a bad omen for Harold, but a good omen for the man who defeated him, William the Conqueror. The comet is represented on the Bayeux Tapestry and described in the tituli as a star. Surviving accounts from the period describe it as appearing to be four times the size of Venus and shining with a light equal to a quarter of that of the Moon. Halley came within 0.10 AU of Earth at that time.

This appearance of the comet is also noted in the "Anglo-Saxon Chronicle". Eilmer of Malmesbury may have seen Halley previously in 989, as he wrote of it in 1066: "You've come, have you? ... You've come, you source of tears to many mothers, you evil. I hate you! It is long since I saw you; but as I see you now you are much more terrible, for I see you brandishing the downfall of my country. I hate you!"

The Irish "Annals of the Four Masters" recorded the comet as "A star [that] appeared on the seventh of the Calends of May, on Tuesday after Little Easter, than whose light the brilliance or light of The Moon was not greater; and it was visible to all in this manner till the end of four nights afterwards." Chaco Native Americans in New Mexico may have recorded the 1066 apparition in their petroglyphs.

The 1145 apparition was recorded by the monk Eadwine. The 1986 apparition exhibited a fan tail similar to Eadwine's drawing. Some claim that Genghis Khan was inspired to turn his conquests toward Europe by the 1222 apparition. The 1301 apparition may have been seen by the artist Giotto di Bondone, who represented the Star of Bethlehem as a fire-colored comet in the Nativity section of his Arena Chapel cycle, completed in 1305. Its 1378 appearance is recorded in the "Annales Mediolanenses" as well as in East Asian sources.

In 1456, the year of Halley's next apparition, the Ottoman Empire invaded the Kingdom of Hungary, culminating in the Siege of Belgrade in July of that year. In a papal bull, Pope Callixtus III ordered special prayers be said for the city's protection. In 1470, the humanist scholar Bartolomeo Platina wrote in his "Lives of the Popes" that,

A hairy and fiery star having then made its appearance for several days, the mathematicians declared that there would follow grievous pestilence, dearth and some great calamity. Calixtus, to avert the wrath of God, ordered supplications that if evils were impending for the human race He would turn all upon the Turks, the enemies of the Christian name. He likewise ordered, to move God by continual entreaty, that notice should be given by the bells to call the faithful at midday to aid by their prayers those engaged in battle with the Turk.

Platina's account is not mentioned in official records. In the 18th century, a Frenchman further embellished the story, in anger at the Church, by claiming that the Pope had "excommunicated" the comet, though this story was most likely his own invention.

Halley's apparition of 1456 was also witnessed in Kashmir and depicted in great detail by Śrīvara, a Sanskrit poet and biographer to the Sultans of Kashmir. He read the apparition as a cometary portent of doom foreshadowing the imminent fall of Sultan Zayn al-Abidin (AD 1418/1420–1470).

After witnessing a bright light in the sky which most historians have identified as Halley's Comet, Zara Yaqob, Emperor of Ethiopia from 1434 to 1468, founded the city of Debre Berhan (tr. City of Light) and made it his capital for the remainder of his reign.

The comet added to the unrest in China on the eve of the Xinhai Revolution that would end the last dynasty in 1911. As James Hutson, a missionary in Sichuan Province at the time, recorded,

The people believe that it indicates calamity such as war, fire, pestilence, and a change of dynasty. In some places on certain days the doors were unopened for half a day, no water was carried and many did not even drink water as it was rumoured that pestilential vapour was being poured down upon the earth from the comet."

The 1910 visitation is also recorded as being the travelling companion of Hedley Churchward, the first known English Muslim to make the Haj pilgrimage to Mecca. However, his explanation of its scientific predictability did not meet with favour in the Holy City.

The comet was also fertile ground for hoaxes. One that reached major newspapers claimed that the Sacred Followers, a supposed Oklahoma religious group, attempted to sacrifice a virgin to ward off the impending disaster, but were stopped by the police.

American satirist and writer Mark Twain was born on 30 November 1835, exactly two weeks after the comet's perihelion. In his autobiography, published in 1909, he said,

I came in with Halley's comet in 1835. It is coming again next year, and I expect to go out with it. It will be the greatest disappointment of my life if I don't go out with Halley's comet. The Almighty has said, no doubt: 'Now here are these two unaccountable freaks; they came in together, they must go out together.'

Twain died on 21 April 1910, the day following the comet's subsequent perihelion. The 1985 fantasy film "The Adventures of Mark Twain" was inspired by the quotation.

Halley's 1910 apparition is distinct from the Great Daylight Comet of 1910, which surpassed Halley in brilliance and was actually visible in broad daylight for a short period, approximately four months before Halley made its appearance.

Halley's 1986 apparition was the least favourable on record. The comet and Earth were on opposite sides of the Sun in February 1986, creating the worst viewing circumstances for Earth observers for the last 2,000 years. Halley's closest approach was 0.42 AU. Additionally, with increased light pollution from urbanization, many people failed to even see the comet. It was possible to observe it in areas outside of cities with the help of binoculars. Further, the comet appeared brightest when it was almost invisible from the northern hemisphere in March and April. Halley's approach was first detected by astronomers David Jewitt and G. Edward Danielson on 16 October 1982 using the 5.1 m Hale telescope at Mount Palomar and a CCD camera. The first person to visually observe the comet on its 1986 return was amateur astronomer Stephen James O'Meara on 24 January 1985. O'Meara used a home-built 24-inch telescope on top of Mauna Kea to detect the magnitude 19.6 comet. On 8 November 1985, Stephen Edberg (then serving as the Coordinator for Amateur Observations at NASA's Jet Propulsion Laboratory) and Charles Morris were the first to observe Halley's Comet with the naked eye in its 1986 apparition.

Although Halley's Comet's retrograde orbit and high inclination make it difficult to send a space probe to it, the 1986 apparition gave scientists the opportunity to closely study the comet, and several probes were launched to do so. The Soviet Vega 1 started returning images of Halley on 4 March 1986, and the first ever of its nucleus, and made its flyby on 6 March, followed by Vega 2 making its flyby on 9 March. On 14 March, the "Giotto" space probe, launched by the European Space Agency, made the closest pass of the comet's nucleus. There were also two Japanese probes, "Suisei" and "Sakigake". The probes were unofficially known as the Halley Armada.

Based on data retrieved by "Astron", the largest ultraviolet space telescope of the time, during its Halley's Comet observations in December 1985, a group of Soviet scientists developed a model of the comet's coma. The comet was also observed from space by the International Cometary Explorer (ICE). Originally International Sun-Earth Explorer 3, the probe was renamed and freed from its Lagrangian point location in Earth's orbit to intercept comets 21P/Giacobini-Zinner and Halley. ICE made its closest approach on March 28, 1986.

Two Space Shuttle missions—the ill-fated STS-51-L (ended by the "Challenger" disaster) and STS-61-E—were scheduled to observe Halley's Comet from low Earth orbit. STS-51-L carried the Shuttle-Pointed Tool for Astronomy (SPARTAN-203) satellite, also called the Halley's Comet Experiment Deployable (HCED). STS-61-E was a "Columbia" mission scheduled for March 1986, carrying the ASTRO-1 platform to study the comet. Due to the suspension of America's manned space program after the "Challenger" explosion, the mission was canceled, and ASTRO-1 would not fly until late 1990 on STS-35.

On 12 February 1991, at a distance of from the Sun, Halley displayed an outburst that lasted for several months, releasing a cloud of dust 300,000 km across. The outburst likely started in December 1990, and then the comet brightened from magnitude 24.3 to magnitude 18.9. Halley was most recently observed in 2003 by three of the Very Large Telescopes at Paranal, Chile, when Halley's magnitude was 28.2. The telescopes observed Halley, at the faintest and farthest any comet has ever been imaged, in order to verify a method for finding very faint trans-Neptunian objects. Astronomers are now able to observe the comet at any point in its orbit.

The next predicted perihelion of Halley's Comet is 28 July 2061, when it is expected to be better positioned for observation than during the 1985–1986 apparition, as it will be on the same side of the Sun as Earth. It is expected to have an apparent magnitude of −0.3, compared with only +2.1 for the 1986 apparition. It has been calculated that on 9 September 2060, Halley will pass within of Jupiter, and then on 20 August 2061 will pass within of Venus. In 2134, Halley is expected to pass within of Earth. Its apparent magnitude is expected to be −2.0.

Halley's calculations enabled the comet's earlier appearances to be found in the historical record. The following table sets out the astronomical designations for every apparition of Halley's Comet from 240 BC, the earliest documented widespread sighting. For example, "1P/1982 U1, 1986 III, 1982i" indicates that for the perihelion in 1986, Halley was the first period comet known (designated 1P) and this apparition was the first seen in half-month U (the second half of October) in 1982 (giving 1P/1982 U1); it was the third comet past perihelion in 1986 (1986 III); and it was the ninth comet spotted in 1982 (provisional designation 1982i). The perihelion dates of each apparition are shown. The perihelion dates farther from the present are approximate, mainly because of uncertainties in the modelling of non-gravitational effects. Perihelion dates of 1531 and earlier are in the Julian calendar, while perihelion dates 1607 and after are in the Gregorian calendar.

Halley's Comet is visible from Earth every 74–79 years.

Halley at first agreed with the longtime consensus that each comet was a different entity making a single visit to the solar system. In 1705, he applied Newton's method to 23 cometary apparitions that had occurred between 1337 and 1698. Halley noted that three of these, the comets of 1531, 1607, and 1682, had very similar orbital elements, and he was further able to account for the slight differences in their orbits in terms of gravitational perturbation by Jupiter and Saturn. Confident that these three apparitions had been three appearances of the same comet, he predicted that it would appear again in 1758–9. (Earlier, Robert Hooke had identified the comet of 1664 with that of 1618, while Giovanni Domenico Cassini had suspected the identity of the comets of 1577, 1665, and 1680. Both were incorrect.) Halley's predicted return date was later refined by a team of three French mathematicians: Alexis Clairaut, Joseph Lalande, and Nicole-Reine Lepaute, who predicted the date of the comet's 1759 perihelion to within one month's accuracy. Halley died before the comet's return; when it returned as predicted, it became known as Halley's Comet (with the latter-day designation of 1P/Halley). The comet next appears in 2061.

Observational history of comets

Comets have been observed by humanity for thousands of years, but it is only in the past few centuries that they have been studied as astronomical phenomena.

Until the sixteenth century, comets were usually considered bad omens of deaths of kings or noble men, or coming catastrophes, or even interpreted as attacks by heavenly beings against terrestrial inhabitants. From ancient sources, such as Chinese oracle bones, it is known that their appearances have been noticed by humans for millennia. The oldest picture of a comet is that of Halley's Comet in the Nuremberg Chronicle for AD 684. One very famous recording of a comet is the appearance of Halley's Comet as a terrifying omen on the Bayeux Tapestry, which records the Norman conquest of England in AD 1066.

Ancient Chinese records of comet apparitions have been particularly useful to modern astronomers. They are accurate, extensive, and consistent over three millennia. The past orbits of many comets have been calculated entirely from these records and most notably they were used in connection with Halley's comet.

In the first book of his "Meteorology", Aristotle propounded the view of comets that would hold sway in Western thought for nearly two thousand years. He rejected the ideas of several earlier philosophers that comets were planets, or at least a phenomenon related to the planets, on the grounds that while the planets confined their motion to the circle of the Zodiac, comets could appear in any part of the sky. Instead, he described comets as a phenomenon of the upper atmosphere, where hot, dry exhalations gathered and occasionally burst into flame. Aristotle held this mechanism responsible for not only comets, but also meteors, the aurora borealis, and even the Milky Way.

A few later classical philosophers did dispute this view of comets. Seneca the Younger, in his "Natural Questions", observed that comets moved regularly through the sky and were undisturbed by the wind, behavior more typical of celestial than atmospheric phenomena. While he conceded that the other planets do not appear outside the Zodiac, he saw no reason that a planet-like object could not move through any part of the sky. However, the Aristotelian viewpoint proved more influential, and it was not until the 16th century that Tycho Brahe demonstrated that comets must exist outside the Earth's atmosphere by measuring the parallax of the Great Comet of 1577 from observations collected by geographically separated observers. Within the precision of the measurements, this implied the comet must be at least four times more distant than from the Earth to the Moon.

Though comets had now been demonstrated to be in space, the question of how they moved would be debated for most of the next century. Even after Johannes Kepler had determined in 1609 that the planets moved about the Sun in elliptical orbits, he was reluctant to believe that the laws that governed the motions of the planets should also influence the motion of other bodies; he believed that comets travel among the planets along straight lines, and it required Edmund Halley to prove that their orbits are in fact curved. Galileo Galilei, although a staunch Copernicanist, rejected Tycho's parallax measurements and his "Discourse on Comets" held to the Aristotelian notion of comets moving on straight lines through the upper atmosphere.

The matter was resolved by the bright comet that was discovered by Gottfried Kirch on November 14, 1680. Astronomers throughout Europe tracked its position for several months. In 1681, the Saxon pastor Georg Samuel Doerfel set forth his proofs that comets are heavenly bodies moving in parabolas of which the Sun is the focus. Then Isaac Newton, in his "Principia Mathematica" of 1687, proved that an object moving under the influence of his inverse square law of universal gravitation must trace out an orbit shaped like one of the conic sections, and he demonstrated how to fit a comet's path through the sky to a parabolic orbit, using the comet of 1680 as an example.

Among the comets with short enough periods to have been observed several times in the historical record, Halley's Comet is unique in that it is consistently bright enough to be visible to the naked eye while passing through the inner Solar System. Since the confirmation of the periodicity of Halley's Comet, other [periodic comet]]s have been discovered through the use of the telescope. The second comet found to have a periodic orbit was Encke's Comet (with the official designation of 2P/Encke). During the period 1819–21 the German mathematician and physicist Johann Franz Encke computed the orbits for a series of comets that had been observed in 1786, 1795, 1805, and 1818, and he concluded that they were same comet, and successfully predicted its return in 1822. By 1900, seventeen comets had been observed through more than one passage through their perihelions, and then recognized as being periodic comets., 305 comets have achieved this distinction, although several of these have disintegrated or been lost.

By 1900 comets were categorized as "periodic", with elliptical orbits, or "non-periodic", one-time with parabolic or hyperbolic orbits. Astronomers believed that planets captured non-periodic comets into elliptical orbits; each planet had a "family" of comets that it captured, with Jupiter's the largest. In 1907 A. O. Leuschner proposed that many non-periodic comets would have elliptical orbits if studied longer, making most comets permanent parts of the solar system, even those with orbital periods of thousands of years. This implied a large group of comets outside the orbit of Neptune, the Oort Cloud.

Isaac Newton described comets as compact and durable solid bodies moving in oblique orbit and their tails as thin streams of vapor emitted by their nuclei, ignited or heated by the Sun. Newton suspected that comets were the origin of the life-supporting component of air. Newton also believed that the vapors given off by comets might replenish the planets' supplies of water (which was gradually being converted into soil by the growth and decay of plants) and the Sun's supply of fuel.

As early as the 18th century, some scientists had made correct hypotheses as to comets' physical composition. In 1755, Immanuel Kant hypothesized that comets are composed of some volatile substance, whose vaporization gives rise to their brilliant displays near perihelion. In 1836, the German mathematician Friedrich Wilhelm Bessel, after observing streams of vapor during the appearance of Halley's Comet in 1835, proposed that the jet forces of evaporating material could be great enough to significantly alter a comet's orbit, and he argued that the non-gravitational movements of Encke's Comet resulted from this phenomenon.

However, another comet-related discovery overshadowed these ideas for nearly a century. Over the period 1864–1866 the Italian astronomer Giovanni Schiaparelli computed the orbit of the Perseid meteors, and based on orbital similarities, correctly hypothesized that the Perseids were fragments of Comet Swift–Tuttle. The link between comets and meteor showers was dramatically underscored when in 1872, a major meteor shower occurred from the orbit of Comet Biela, which had been observed to split into two pieces during its 1846 apparition, and was never seen again after 1852. A "gravel bank" model of comet structure arose, according to which comets consist of loose piles of small rocky objects, coated with an icy layer.

By the middle of the twentieth century, this model suffered from a number of shortcomings: in particular, it failed to explain how a body that contained only a little ice could continue to put on a brilliant display of evaporating vapor after several perihelion passages. In 1950, Fred Lawrence Whipple proposed that rather than being rocky objects containing some ice, comets were icy objects containing some dust and rock. This "dirty snowball" model soon became accepted and appeared to be supported by the observations of an armada of spacecraft (including the European Space Agency's "Giotto" probe and the Soviet Union's "Vega 1" and "Vega 2") that flew through the coma of Halley's Comet in 1986, photographed the nucleus, and observed jets of evaporating material.

According to research, large comets with a radius of over 10 kilometers could contain liquid water at their cores by the decay of radioactive isotopes of aluminum or iron.

Since 1985, a total of 8 comets have been visited by spacecrafts. These were the comets Halley, Borrelly, Giacobini–Zinner, Tempel 1, Wild 2, Hartley 2, Grigg–Skjellerup and Churyumov–Gerasimenko, generating a host of new findings. In addition, the spacecraft "Ulysses" unexpectedly traversed the tail of Comet McNaught.

He also developed a method of eliminating systematic errors in positioning brighter comets that resulted in a more accurate prediction of the Halley's Comet. A recalculation of the path of Halley's comet to 2317 BC confirmed that the Greeks had already seen the comet on 466 B.C.
He discovered seven minor planets including 3683 Baumann, 4378 Voigt (named after Hans-Heinrich Voigt), 9938 Kretlow and 4349 Tibúrcio at ESO's La Silla Observatory in northern Chile.

Werner Landgraf

Werner Landgraf (29 July 1959 in Mainz) is a German astrophysicist and a discoverer of minor planets.

W. Landgraf studied physics at the University of Siegen in 1977 and was working on his first astronomical projects. His earliest work was very inspired by Brian G. Marsden and Victor Shor. Two years later, he joined the Department of Astrophysics of University of Göttingen. There he presented his thesis "The calculation of atmospheric models and line profiles for the analysis of stellar spectra". He graduated from the university in 1983, and then he worked until 1988 on his dissertation "Nongravitational forces of Comet Halley"., under supervision by Hans-Heinrich Voigt.

In 1986, W. Landgraf received a teaching position at the University of Siegen. In addition to the main lecture about astronomy and astrophysics, he gave lectures also on solar system objects and their motion, Relativity and Cosmology.

W. Landgraf's work mainly concerns the verification and determination of astronomical constants of the reference system, the masses of the planets, non-gravitational forces and the verification of the gravitational law within the solar system. He developed and improved methods for identifying and calculating the orbits of different objects in the solar system. He busied himself in this work with numerous minor planets with emphasis on the near-Earth asteroids, comets, their long term dynamics, and with the observation of small planets and comets.

He examined the properties, individuation and interaction of causets, which each starts from the affirmation that "everything what exists, acts" as its first element and as its sphere of validity successively produces really news, not predetermined by nor contained in and linear independent from old, and that the earliest elements or occurred facts and their aftereffects appear as its internal logical, geometrical, physical properties (namely, the first and the next 1,2,4... elements of the same rank, represent its dimensions and corresponding primary natural forces). Applied to our real world, this would suggest that successive events, world points, and their actions already would be an own "discrete" first dimension and producing force, corresponding to proper time (inclusive a discrete variance and limited vality range of facts and their effects), followed by the similar time; a kinematic extension, and two equivalent curvature-defining geometric extensions. This makes plausible that the dimensions of the world increase proportionally to their elementary units, in a not-localizable manner, very classically and approximately corresponding to a radiation with a wavelength of about the world's size, keeping the biggest part of the world's energy, per each elementary space inclusive at any background or surface one such photon or information and a pressure canceling the gravitational deceleration of expansion

In 1987, asteroid 3132 Landgraf was named after him.


How do anti toxins work?

The antitoxin is generally less stable than the toxin due to its degradation by proteases already present in the cell. For example, in the ccdAB proteic addiction module, the "Lon" protease  degrades the antitoxin, but also serves many unrelated proteolytic roles, such as degrading oxidated mitochondrial products. This may indicate that the development of these addiction molecules "co-opted" existing cell utilities.
The antitoxin in proteic addiction modules functions by binding directly to the toxin and preventing its mode of action. Once the antitoxin has bound to the toxin, the toxin prevents the proteases normally responsible for degrading antitoxin to do so, maintaining the neutralization of that individual toxin molecule.

Addiction module

Addiction modules are toxin-antitoxin systems. Each consists of a pair of genes that specify two components: a stable toxin and an unstable antitoxin that interferes with the lethal action of the toxin. Found first in E. coli on low copy number plasmids, addiction modules are responsible for a process called the postsegregational killing effect. When bacteria lose these plasmid(s) (or other extrachromosomal elements), the cured cells are selectively killed because the unstable antitoxin is degraded faster than the more stable toxin. The term "addiction" is used because the cell depends on the de novo synthesis of the antitoxin for cell survival. Thus, addiction modules are implicated in maintaining the stability of extrachromosomal elements.

Proteic addiction modules use proteins as toxins and antitoxins, as opposed to RNA or other methods. The known proteic addiction modules all have similar shared characteristics, including placement of the antitoxin gene relative to the toxin gene, method of toxin neutralization by the antitoxin, and autoregulation of the addiction module by the antitoxin or toxin:antitoxin complex.
In protein-based addiction modules, the genes encoding the toxin and antitoxin lie adjacent to each other and are continuously expressed under one operon. To ensure survival of the host when the addiction module is present, more antitoxin must be produced than toxin (to counter the shorter lifespan of the antitoxin molecules). Safe ratios of the toxin and antitoxin are maintained at least in part by both this overexpression and by having the antitoxin-encoding gene encoded upstream from the toxin gene, so that the antitoxin is available to immediately neutralize the toxin. This upstream placement of the antitoxin gene is found in all proteic addiction modules.
In addition, the transcription of the whole addiction module is often negatively autoregulated (i.e. the presence of its products decreases its transcriptional rate) by the formation of toxin:antitoxin complexes.

Antisense RNA-type addiction modules use a regulatory strand of RNA which is at least partially "antisense" (having complimentary base pair encoding) to bind to toxin RNA, and thus prevent toxin transcription. This antisense RNA molecule plays the role of antitoxin, similar to the proteic equivalent described above, and is similarly degraded at a faster rate than the toxin mRNA it inhibits. In addition, the transcription of the antitoxin RNA is heavily upregulated by a strong promoter which ensures excess antitoxin in cells which have a functioning addiction module.

An antitoxin is an antibody with the ability to neutralize a specific toxin. Antitoxins are produced by certain animals, plants, and bacteria. Although they are most effective in neutralizing toxins, they can kill bacteria and other microorganisms. Antitoxins are made within organisms, but can be injected into other organisms, including humans. This procedure involves injecting an animal with a safe amount of a particular toxin. Then, the animal’s body makes the antitoxin needed to neutralize the toxin. Later, the blood is withdrawn from the animal. When the antitoxin is obtained from the blood, it is purified and injected into a human or other animal, inducing passive immunity. To prevent serum sickness, it is often best to use antitoxin generated from the same species (e.g. use human antitoxin to treat humans).

Antitoxin

Antitoxins to diphtheria and tetanus toxins were produced by Emil Adolf von Behring and his colleagues from 1890 onwards. The use of diphtheria antitoxin for the treatment of diphtheria was regarded by "The Lancet" as the "most important advance of the [19th] Century in the medical treatment of acute infectious disease".

In 1888 Behring was sent to Berlin for a brief service at the Academy for Military Medicine. In 1889, he joined the Institute for Hygiene of the University of Berlin, then presided over by Robert Koch. Between 1889 and 1895 Behring developed his pioneering ideas on serum therapy and his theory of antitoxins.

Early 1887, in Bonn, Behring had found that the serum of tetanus-immune white rats contained a substance that neutralized anthrax bacilli. He saw this as the cause of “resistance.”

On 4 December 1890 Behring and Kitasato Shibasaburō published their first paper on blood-serum therapy. On 11 December another report, signed by Behring, discussed the blood-serum therapy not only in the treatment of tetanus, but also of diphtheria.

When Paul Ehrlich demonstrated in 1891 that even vegetable poisons led to the formation of antitoxins in the organism, Behring’s theory was confirmed.

An antitoxin for scarlet fever was developed in 1924 simultaneously by Raymond Dochez and Gladys and George Frederick Dick.


When was Taja born?

Taja Sevelle (born Nancy Richardson, January 7, 1962 in Minneapolis, Minnesota) is an American singer, songwriter and musician, best known for her 1987 single, "Love Is Contagious" and for the non-profit organization Urban Farming, which she founded in 2005.

Taja Sevelle

Sevelle signed a record contract with Prince's Paisley Park Records in 1987. From the Prince Vault Website, the following information about her recording history with Prince may be known: "Taja Sevelle is the first studio album by Taja Sevelle, and is her only album to feature writing input by Prince.

Two of the album's ten tracks were written (or co-written) by Prince, although the album was produced by Minneapolis musician Chico Bennett.

Although Taja Sevelle had signed to Paisley Park Records when it was formed in 1985, she mainly worked with Warner Bros. executives on the album, and Prince's involvement was minimal; he submitted the songs in late 1986 after Michael Jackson had rejected "Wouldn't You Love To Love Me?" for his album "Bad".

Taja Sevelle was first featured on background vocals on Prince & the Revolutions 1985 album "Around the World in a Day" on the song "The Ladder".

Both songs with Prince involvement were not initially designed for Taja Sevelle and had initially been recorded earlier in his career. "Wouldn't You Love To Love Me?" was first recorded in 1976-1977, before Prince had even recorded his first album "For You", and "If I Could Get Your Attention" was first recorded in May 1986.

The album produced four singles, "Love Is Contagious" (released shortly before the album), "Wouldn't You Love To Love Me?", "Popular" and "Take Me For A Ride".

It failed to chart in the US, but reached number 48 in the UK.

During the 1990s, Sevelle wrote several songs for Warner Music.

In 2005, Taja founded the non-profit organization Urban Farming. Its mission is "to create an abundance of food for people in need by supporting and encouraging the establishment of gardens on unused land and space while increasing diversity, raising awareness for health and wellness, and inspiring and educating youth, adults and seniors to create an economically sustainable system to uplift communities around the globe."

The organization began by planting 3 gardens of free food in Detroit and there are now over 63,400 gardens in 61 countries around the world that are a part of the Urban Farming Global Food Chain.