Researchers at MIT have discovered an Earth-sized exoplanet named Kepler 78b that whips around its host star in a mere 8,5 hours — one of the shortest orbital periods ever detected.

The planet is extremely close to its star — its orbital radius is only about three times the radius of the star — and the scientists have estimated that its surface temperatures may be more than 2 700 degrees Celsius. In such a scorching environment, the top layer of the planet is likely completely melted, creating a massive, roiling ocean of lava.

What’s most exciting to scientists is that they were able to detect light emitted by the planet — the first time that researchers have been able to do so for an exoplanet as small as Kepler 78b. This light, once analysed with larger telescopes, may give scientists detailed information about the planet’s surface composition and reflective properties.

Kepler 78b is so close to its star that scientists hope to measure its gravitational influence on the star. Such information may be used to measure the planet’s mass, which could make Kepler 78b the first Earth-sized planet outside our own solar system whose mass is known.

The findings were published in The Astrophysical Journal.

– Jennifer Chu, MIT

Source: MIT