Astronomy & Space

Planet-hunting TESS spacecraft finds exoplanet smaller than Earth – Astronomy Now

June 30, 2019 • By
The TESS spacecraft has discovered three planets orbiting a small star 35 gentle years from Earth, together with one smaller than Earth and two barely bigger. All three orbit too near their solar for water to exist as a liquid, however the system might maintain clues concerning the evolution of Venus-like worlds. Picture: Goddard House Flight Heart

The Transiting Exoplanet Survey Satellite tv for pc, or TESS, has found an exoplanet smaller than Earth orbiting a small star 35 gentle years from Earth. The exoplanet is about 80 p.c the scale of Earth and orbits its host solar, an M dwarf often known as L 98-59, each 2.25 days, receiving 22 instances the photo voltaic radiation as Earth receives from the Solar. Two different planets within the L 98-59 system full their orbits each 3.7 and seven.5 days respectively.

“The discovery is a great engineering and scientific accomplishment for TESS,” stated Veselin Kostov, an astrophysicist at NASA’s Goddard House Flight Heart in Greenbelt, Maryland, and the SETI Institute in Mountain View, California. “For atmospheric studies of small planets, you need short orbits around bright stars, but such planets are difficult to detect. This system has the potential for fascinating future studies.”

Not one of the newly found planets orbits within the star’s liveable zone the place water can exist as a liquid and as such they’d not be candidates for all times as it’s recognized on Earth. The floor temperature of the small innermost planet, L 98-59b, is round 330 C (620 F). The 2 extra distant planets, with radii of 1.four and 1.6 instances that of Earth, are additionally hellish by Earthly requirements with temperatures starting from 230 C (440 F) to 130 C (260 F).

Whereas nicely contained in the liveable zone, all three planets occupy the so-called Venus zone the place planets with preliminary Earth-like atmospheres might expertise the kind of runaway greenhouse impact answerable for a Venus-like ambiance.

“If we viewed the Sun from L 98-59, transits by Earth and Venus would lead us to think the planets are almost identical, but we know they’re not,” stated Goddard astrophysicist Joshua Schlieder, co-author of as paper describing the observations in The Astronomical Journal.

“We still have many questions about why Earth became habitable and Venus did not,” he stated. “If we can find and study similar examples around other stars, like L 98-59, we can potentially unlock some of those secrets.”