Brian G. Marsden facts for kids

Brian Geoffrey Marsden (born August 5, 1937 – died November 18, 2010) was a British astronomer. Astronomers study space, stars, and planets. He was the director of the Minor Planet Center (MPC) for many years. This center is part of the Center for Astrophysics | Harvard & Smithsonian. He became director emeritus in 2006.

Early Life and Education

Brian Marsden went to school at The Perse School in Cambridge, England. He later studied at New College, Oxford and Yale University. He earned his PhD at Yale. His teacher and mentor there was Dirk Brouwer.

Studying Asteroids and Comets

Marsden was an expert in celestial mechanics and astrometry. These are fields of study that involve how objects move in space and how to measure their positions. He gathered information about where asteroids and comets were located. Then, he used this data to figure out their paths, called orbits. He could often do this even with very little information. He would then share where these objects would be in the future through the International Astronomical Union (IAU).

He was also the director of the Central Bureau for Astronomical Telegrams (CBAT) for many years. This group shares important news about new discoveries in space.

Finding Lost Space Objects

Marsden was very good at finding asteroids and comets that had been "lost." Sometimes, when an asteroid or comet was first found, not enough information was collected. This meant scientists couldn't predict where it would go next. Later, a new discovery might actually be one of these lost objects. Marsden would calculate its orbit backwards in time. He would then match it with old records of the lost object.

This was especially hard for comets. Comets can release gas, which can slightly change their path. But Marsden was skilled at figuring out these extra forces. A famous example is when he correctly predicted the return of Comet Swift-Tuttle in 1992. This comet had been lost for a long time.

Predicting a Comet Crash

In 1993, Marsden made an important prediction. He figured out that Comet Shoemaker-Levy 9 was on a path to hit Jupiter. This collision happened in July 1994. It was the first time scientists had ever successfully predicted a comet hitting a planet.

Asteroid Scare

In 1998, Marsden calculated that an asteroid, (35396) 1997 XF11, had a small chance of hitting Earth in 2028. He decided to tell the public about this. Other astronomers quickly showed that the calculation was not quite right. The asteroid was not going to hit Earth.

Marsden later said that this public announcement was a strategy that needed "rethinking." NASA asked astronomers to talk to each other first before making such big public announcements. Even though he faced some criticism, Marsden believed it was important to bring attention to the need for better ways to find asteroids. He said, "Much as the incident was bad for my reputation, we needed a scare like that to bring attention to this problem."

Pluto's New Classification

Marsden also played a role in the discussion about Pluto. He suggested that Pluto should be listed as both a planet and a minor planet. He even thought it should be given the asteroid number 10000. This idea was not accepted at first.

However, in 2006, a similar idea was approved. Pluto was then called minor planet 134340. It was also named a dwarf planet. Marsden had pushed for Pluto to be reclassified. This was because many new objects were being found beyond Neptune, called Trans-Neptunian objects. These discoveries were made possible by new telescopes.

At a meeting in Prague in 2006, the International Astronomical Union voted on this. They decided that Pluto and three asteroids would be called "dwarf planets." Dwarf planets are objects that have not cleared their orbits of other space debris.

Family Life

Brian Marsden was married to Nancy Lou Zissell. They had a daughter named Cynthia and a son named Jonathan. He even named a minor planet, 2298 Cindijon, after them. Brian said his mother inspired his interest in astronomy. She showed him a partial solar eclipse of September 10, 1942. He was very impressed that the date and time of such an event could be predicted so far in advance.

Honors and Recognition

Awards

• Merlin Medal and Gift of the British Astronomical Association (1965)
• Walter Goodacre Medal of the British Astronomical Association (1979)
• George Van Biesbroeck Prize of the American Astronomical Society (1989)
• Brouwer Award of the Division on Dynamical Astronomy of the American Astronomical Society (1995)
• Royal Astronomical Society Award for Service to Astronomy and Geophysics (2006)
• Member of the Norwegian Academy of Science and Letters

Named after him

• Asteroid 1877 Marsden
• Marsden Group of sun-grazing comets

See also

In Spanish: Brian Marsden para niños