The calculations were key to estimating how much time the NASA/ESA/CSA James Webb Space Telescope would need to confirm the basic composition of an atmosphere - if there is one. The team’s models are the first to detail differences in the chemical signatures generated by rocky planets near the habitable zone’s interior boundary, based on variables including the planet’s size, mass, chemical makeup, surface temperature and pressure, atmospheric height and cloud cover. “It will teach us something fundamental about how rocky planets evolve with increasing starlight, and about what will one day happen to us and Earth.” “Looking at this planet will tell us what’s happening on this inner edge of the habitable zone - how long a rocky planet can maintain habitability when it starts to get hot,” Dr.

To explore the range of possible atmospheres and assess whether transmission spectra can illuminate that difference, the astronomers created seven models for LP890-9c. “This makes LP 890-9c a key to understanding how Venus and Earth evolved.” “However, LP 890-9c, receives 91% as much solar radiation as Earth, placing it within both the conservative and empirical habitable zone.” “LP 890-9c is part of a two-planet system with the inner planet, LP 890-9b, first detected by TESS in a 2.73-day orbit, inward of the habitable zone,” said Cornell University astronomer Lisa Kaltenegger and her colleagues. The outer planet, LP 890-9c, is similar in size to the first (about 37% larger than Earth) but has a longer orbital period of about 8.5 days. The inner planet, LP 890-9b, is about 30% larger than Earth and completes an orbit around the star in just 2.73 days. LP 890-9, which is orbited by at least two exoplanets, is the second-coolest star found to host planets after TRAPPIST-1. Otherwise known as TOI-4306 and SPECULOOS-2, the star has a mass of only 0.16 solar masses, a radius of 0.12 solar radii, and a temperature of 2,850 K (2,577 degrees Celsius, or 4,671 degrees Fahrenheit).

LP 890-9 is located approximately 104 light-years away from Earth in the constellation of Eridanus. Image credit: Adeline Deward, RISE-Illustration. LP 890-9c, also known as SPECULOOS-2c, is providing important insights about conditions at the inner edge of a star’s habitable zone and why Earth and Venus developed so differently.

Stroke reveal after effects