NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered a new planet, the tiniest of its finds so far. It is between the sizes of Mars and Earth and orbits a bright, cool, nearby star. It has been named L 98-59b.
The TESS mission feeds our desire to understand where we came from and whether we are alone in the universe, NASA said in a statement on its website. One of TESS’s goals is to build a catalogue of small, rocky planets on short orbits around very bright, nearby stars for atmospheric study.
Apart from L 98-59b, two other worlds orbit the same star. While all three planets’ sizes are known, further study with other telescopes will be needed to determine if they have atmospheres and, if so, which gases are present, NASA said.
“The discovery is a great engineering and scientific accomplishment for TESS. 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,” Veselin Kostov, an astrophysicist at the Goddard Space Flight Center and the SETI Institute, said in the NASA statement. A paper on the findings, led by Kostov, was published in the June 27 issue of The Astronomical Journal.
L 98-59b is around 80% Earth’s size. The two other worlds in the system, L 98-59c and L 98-59d, are respectively around 1.4 and 1.6 times Earth’s size. Their host star, L 98-59, is about one-third the mass of the Sun and lies about 35 light-years away. While L 98-59b is a record for TESS, even smaller planets have been discovered in data collected by NASA’s Kepler satellite, including Kepler-37b, which is only 20% larger than the Moon. —Source: NASA