Exoplanet L 98-59d, illustration. Exoplanet L 98-59d was discovered by NASA's Transiting Exoplanet Survey Satellite (TESS), which measures the dip in light as planets pass between the host star and TESS. L 98-59c is around 1.6 times the Earth's size and lies too close to the host star for liquid water to exist. L 98-59d is thus considered to be outside the habitable zone. The host star L 98-59 is an M Dwarf star and is orbited by the other exoplanets L 98-59a and L 98-59c.