Related topics: orbit · stars · planets · solar system

Will we know if TRAPPIST-1e has life?

The search for extrasolar planets is currently undergoing a seismic shift. With the deployment of the Kepler Space Telescope and the Transiting Exoplanet Survey Satellite (TESS), scientists discovered thousands of exoplanets, ...

Radiating exoplanet discovered in 'perfect tidal storm'

Can tidal forces cause an exoplanet's surface to radiate heat? This is what a study accepted to the Astronomical Journal hopes to address as a team of international researchers used data collected from ground-based instruments ...

That starry night sky? It's full of eclipses

Our star, the sun, on occasion joins forces with the moon to offer us Earthlings a spectacular solar eclipse—like the one that will be visible to parts of the United States, Mexico, and Canada on April 8.

The search for the perfect coronagraph to find Earth 2.0

Studying exoplanets is made more difficult by the light from the host star. Coronagraphs are devices that block out the star light and both JWST and Nancy Grace Roman Telescope are equipped with them. Current coronagraphs ...

Could Earth life survive on a red dwarf planet?

Even though exoplanet science has advanced significantly in the last decade or two, we're still in an unfortunate situation. Scientists can only make educated guesses about which exoplanets may be habitable. Even the closest ...

Astronomers discover new Saturn-sized exoplanet

An international team of astronomers reports the discovery of a new exoplanet orbiting a solar-type star. The newfound alien world, designated TOI-1135 b is young, hot and comparable in size to Saturn. The discovery was detailed ...

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Extrasolar planet

An extrasolar planet, or exoplanet, is a planet beyond our Solar System, orbiting a star other than our Sun. As of June 2009[update], 353 exoplanets are listed in the Extrasolar Planets Encyclopaedia. The vast majority have been detected through radial velocity observations and other indirect methods rather than actual imaging. Most announced exoplanets are massive gas giant planets thought to resemble Jupiter, but this is a selection effect (bias) due to limitations in detection technology. Projections based on recent detections of much smaller worlds suggest that lightweight, rocky planets will eventually be found to outnumber extrasolar gas giants.

Extrasolar planets became a subject of scientific investigation in the mid-19th century. Many astronomers supposed that such planets existed, but they had no way of knowing how common they were or how similar they might be to the planets of our Solar System. The first confirmed radial velocity detection was made in 1995, revealing a gas giant planet in a four-day orbit around the nearby G-type star 51 Pegasi. The frequency of detections has tended to increase on an annual basis since then. It is estimated that at least 10% of sun-like stars have planets, and the true proportion may be much higher. The discovery of extrasolar planets sharpens the question of whether some might support extraterrestrial life.

Currently Gliese 581 d, the fourth planet of the red dwarf star Gliese 581 (approximately 20 light years from Earth), appears to be the best example yet discovered of a possible terrestrial exoplanet that orbits within the habitable zone surrounding its star. Although initial measurements suggested that Gliese 581 d resided outside the so-called "Goldilocks Zone", additional measurements place it firmly within.

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