Exoplanet

About Exoplanet

What is a Exoplanet?

An exoplanet or extrasolar planet is any planet detected beyond our solar system. Exoplanets orbit around other stars and are very hard to see directly with telescopes. They are hidden by the bright glare of the stars they orbit.

So, astronomers use other ways to detect and study these distant planets. They search for exoplanets by looking at the effects these planets have on the stars they orbit. More than 4,000 exoplanets are known, and about 6,000 await further confirmation.

How to detect exoplanets

Planets are much fainter than the stars they orbit. Hence, exoplanets are extremely difficult to detect. By far, the most successful technique for finding and studying exoplanets has been the radial velocity method, which measures the motion of host stars in response to gravitational tugs by their planets. Swiss astronomers Michel Mayor and Didier Queloz discovered the first planet using this technique, 51 Pegasi b, in the 1990s. Other techniques that have detected exoplanets are - pulsation timing, microlensing, and direct imaging.

The nearest exoplanets are located 4.2 light-years from Earth and orbit Proxima Centauri, the closest star to the Sun.

Future research

NASA's Kepler mission, launched on March 6, 2009, found that about 1 in 4 Sun-like stars had a planet analogous to Earth. In 2010 the Kepler team announced its first discoveries: four gas giant planets somewhat larger than Jupiter and one planet slightly larger than Neptune that is more enriched in heavy elements; all five orbit very close to their stars. In 2011 the Kepler said that they had discovered a planet, Kepler-22b, that was the first to be found in the habitable zone of a star like the Sun. They also discovered the first Earth-sized exoplanets, Kepler-20e and Kepler-20f. By the end of its mission in 2018, Kepler had discovered 2,741 planets, about two-thirds of all known exoplanets.

Other research carried out by Trappist telescope on Earth and the Spitzer Space Telescope were used to discover seven Earth-sized planets in this system, three of which are in the habitable zone. TESS (Transiting Exoplanet Survey Satellite) is another mission by NASA's Explorer's programme, designed to search for exoplanets using the transit method in an area 400 times larger than that covered by the Kepler mission.

Latest Updates on Exoplanet

NASA captures 1st direct image of exoplanet outside our solar system

The exoplanet is about six to 12 times the mass of Jupiter, and these observations could help narrow that down even further

Updated On: 02 Sep 2022 | 2:38 PM IST

NASA's James Webb detects water on distant planet orbiting Sun-like star

NASA's James Webb Space Telescope detected signs of water, evidence for clouds and haze, in the atmosphere of a hot, puffy gas giant planet orbiting a Sun-like star over a thousand light years away

Updated On: 13 Jul 2022 | 12:37 PM IST

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Just 40 light years away, 7 Earth-like planets with similar compositions

A new research published in The Planetary Science Journal has now evoked a renewed interest in the system, with astronomers finding that the exoplanets have remarkably similar densities

Updated On: 25 Jan 2021 | 12:07 PM IST