- Byname of:
- Geoffrey William Marcy
- Born:
- September 29, 1954, St. Clair Shores, Michigan, U.S. (age 72)
- Subjects Of Study:
- planet
Geoffrey Marcy
-
Who is Geoffrey Marcy?
Geoffrey Marcy (born in 1954) is an American astronomer known for his work in detecting extrasolar planets using Doppler shifts. He earned a Ph.D. in astronomy and astrophysics from the University of California, Santa Cruz, in 1982. In 1995, two Swiss scientists detected the first planet circling a star outside Earth’s solar system. Marcy confirmed their discovery, and he and Butler discovered two more extrasolar planets the following year. In 1999, he and his colleagues discovered the first extrasolar multiple planet system, orbiting the star Upsilon Andromedae in the Andromeda constellation. He was a professor of astronomy at the University of California, Berkeley, from 1999 to 2015, when he resigned amid allegations of sexual harassment. That same year, SFSU terminated his position.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What is Geoffrey Marcy known for in astronomy?
Geoffrey Marcy is an American astronomer notable for his contributions to the discovery of extrasolar planets. He used Doppler shifts to detect the "wobble" of stars caused by the gravitational pull of orbiting planets, leading to the identification of hundreds of planetary bodies, including multiple star systems. In 1999, Marcy and his team discovered the first extrasolar multiple planet system, orbiting the star Upsilon Andromedae. He also combined forces with NASA’s Kepler mission in 2009 to find Earth-sized planets.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What important discoveries has Geoffrey Marcy made?
Geoffrey Marcy is an American astronomer notable for his contributions to the discovery of extrasolar planets. Marcy refined a light analyzer that could detect shifts, confirming the first discovery of an extrasolar planet by Swiss scientists Michel Mayor and Didier Queloz in 1995.
Marcy's other achievements include:
* Discovery of two more extrasolar planets with Paul Butler in the following year.
* Discovery of the first extrasolar multiple planet system, orbiting the star Upsilon Andromedae, in 1999.
* Detection of a planet that was approximately seven times the mass of Earth in 2005.
* Detected almost 150 exoplanets by using the telescopes at the W.M. Keck Observatory in Hawaii.2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How did Geoffrey Marcy help find planets outside our solar system?
Geoffrey Marcy's work in detecting extrasolar planets involved using Doppler shifts to measure the motion of host stars in response to gravitational pulls from their planets. He refined a light analyzer that could detect shifts in the wavelengths of light traveling from the star to Earth, confirming the existence of planets outside Earth's solar system. In 1999, Marcy discovered a star with a wobble, which suggested that a huge planet would pass directly in front of the star and block some of its light.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why are Marcy's discoveries about exoplanets important for science?
Geoffrey Marcy's work significantly advanced astronomy, notably through his use of Doppler shifts to detect extrasolar planets. In 1995, he confirmed the first discovery of an exoplanet orbiting a star outside our solar system made by Michel Mayor and Didier Queloz. Subsequently, Marcy and his team discovered hundreds more, including the first extrasolar multiple planet system.
Marcy's refined light detector, improving its precision from 15 meters/second to 1 meter/second, increased the likelihood of detecting Earth-sized planets. His contributions include discovering a planet just seven times the mass of Earth and collaborating with NASA's Kepler mission to further investigate exoplanets similar to Earth. These findings contribute to identifying potentially habitable planets and understanding planetary systems beyond our own.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What impact did Geoffrey Marcy's work have on our understanding of the universe?
Geoffrey Marcy's work significantly advanced our understanding of the universe through the detection of extrasolar planets. He used Doppler shifts to discover hundreds of planetary bodies, including those in multiple star systems. Marcy confirmed the first discovery of an exoplanet and, along with Paul Butler, found two more. In 1999, he identified a star with a wobble indicating a planet passing in front of it, and he also discovered the first extrasolar multiple planet system orbiting Upsilon Andromedae. His work with NASA's Kepler mission further aided in identifying Earth-sized planet candidates.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Geoffrey Marcy (born September 29, 1954, St. Clair Shores, Michigan, U.S.) is an American astronomer whose use of Doppler shifts to detect extrasolar planets led to the discovery of several hundred planetary bodies in multiple star systems.
Marcy was raised in the suburbs of Los Angeles. When he was 14, his mother, an anthropologist, and his father, an aerospace engineer, bought him a telescope, engendering an early interest in astronomy. Marcy received a bachelor’s degree in physics and astronomy from the University of California, Los Angeles, in 1976. In 1982 he earned a doctorate in astronomy and astrophysics from the University of California, Santa Cruz. From 1982 to 1984 he studied at the Mount Wilson and Las Campanas observatories in Pasadena, California, having received a Carnegie fellowship from the Carnegie Institution of Washington, D.C.
After deciding to devote himself to searching for extrasolar planets in 1983, the next year he moved on to a professorship at San Francisco State University (SFSU), where he recruited a graduate student, Paul Butler, to help him develop instrumentation that would be sensitive enough to indicate the presence of such faraway objects. His colleagues thought him foolish to spend time on what they considered a futile pursuit, questioning the very existence of such bodies as well as the feasibility of detecting them. Though no telescope was powerful enough to see such a planet directly, Marcy was intrigued by the theory, put forth by Canadian astronomer Gordon Walker, that a large planet might exert enough gravitational force on its star that the star would move slightly. This motion, referred to as a “wobble,” would reveal itself as a slight shift in the wavelengths of light traveling from the star to Earth. Eventually Marcy and Butler refined a light analyzer that could detect such shifts.
Using this technique, two Swiss scientists, Michel Mayor and Didier Queloz, in 1995 became the first astronomers to detect a planet circling a star outside Earth’s solar system. Marcy confirmed their discovery, and the following year he and Butler discovered two more extrasolar planets. A succession of similar discoveries followed. In 1999 Marcy found a star with a wobble that suggested a huge planet would pass directly in front of the star and thereby block some of the star’s light, and on November 7 of that year one of his colleagues noted a 1.7 percent decline in the brightness of the star at exactly the time Marcy had predicted. That year he and his colleagues also discovered the first extrasolar multiple planet system, orbiting the star Upsilon Andromedae in the Andromeda constellation. As a reward for his groundbreaking research, Marcy was appointed a professor of astronomy at the University of California, Berkeley, in 1999 and accepted an invitation to head the university’s Center for Integrative Planetary Science, which was founded in 2001. He remained as an adjunct professor at San Francisco State. However, amid allegations of sexual harassment, he resigned from Berkeley in 2015, and that year SFSU terminated his position.
Marcy and his team continued to refine the precision of their light detector, reducing the Doppler shift precision of the instrument from around 15 metres/second in 1995 to 1 metre/second in 2005. The exactitude of the measurements made it increasingly likely that a planet similar to Earth in size though orbiting much closer to its star than Earth’s distance from the Sun could be detected. In June of that year the team announced that they had been able to perceive a planet that was the smallest yet, approximately seven times the mass of Earth. In 2009 Marcy, who had discerned many of the almost 150 exoplanets to his credit by using the telescopes at the W.M. Keck Observatory in Hawaii, combined forces with NASA’s Kepler mission. The Kepler telescope, mounted on a satellite, transmitted information on candidates for Earth-sized planets back to Marcy and his team, who then used the Keck telescopes to obtain further information and investigate the exoplanet’s similarity to Earth.
In April 2000 Marcy was named California Scientist of the Year. He was presented with the NASA Medal for Exceptional Scientific Achievement in 2003 and received the Shaw Foundation Prize in 2005.