NASA planet hunter satellite TESS has discovered an Earth sized planet that has strong chances of the presence of water on it.
According to the NASA, its Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star’s habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface.
Scientists confirmed the find, called TOI 700 d, using NASA’s Spitzer Space Telescope and have modeled the planet’s potential environments to help inform future observations.
TOI 700 d is one of only a few Earth-size planets discovered in a star’s habitable zone so far. Others include several planets in the TRAPPIST-1 system and other worlds discovered by NASA’s Kepler Space Telescope.
NASA’s TESS discovered its first Earth-size planet in a star’s habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. @NASAspitzer followed up and confirmed it. https://t.co/k6XGFSuliy pic.twitter.com/S0r8wLqcp7
— NASA Universe (@NASAUniverse) January 7, 2020
“TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars,” said Paul Hertz, astrophysics division director at NASA Headquarters in Washington.
“Planets around nearby stars are easiest to follow-up with larger telescopes in space and on Earth. Discovering TOI 700 d is a key science finding for TESS. Confirming the planet’s size and habitable zone status with Spitzer is another win for Spitzer as it approaches the end of science operations this January”, Paul added.
TESS initially misclassified the star, which meant the planets appeared larger and hotter than they actually are. But several amateur astronomers, including high school student Alton Spencer – who works with members of the TESS team – identified the error.
“When we corrected the star’s parameters, the sizes of its planets dropped, and we realised the outermost one was about the size of Earth and in the habitable zone,” said Emily Gilbert, a graduate student at the University of Chicago.
The discovery was later confirmed by the Spitzer Space Telescope.
A few other similar planets have been discovered before, notably by the former Kepler Space Telescope, but this is the first one discovered by TESS, which was launched in 2018.
TESS stabilizes on one area of the sky to detect whether objects – planets – pass in front of stars, which causes a temporary drop in the stars’ luminosity. This allows TESS to infer the presence of a planet, its size and orbit.
Star TOI 700 is small, about 40 percent of the size of the Earth’s Sun and only about half as hot.
TESS discovered three planets in orbit, named TOI 700 b, c and d. Only “d” is in the so-called habitable zone, not too far from and not too close to the star, where the temperature could allow the presence of liquid water.
It is about 20 percent larger than Earth and orbits its star in 37 days. Planet 700 d receives 86 percent of the energy that Earth receives from the Sun.