Astronomers have discovered a planet, BD+05 4868 Ab, that is being melted by its host star and losing mass at an alarming rate. The tiny world has a comet-like tail stretching up to 9 million kilometers behind it, making it the least habitable planet ever discovered.
The planet’s surface temperature is so high that liquid rock is boiling away into space, condensing into a rocky tail. Its orbit brings it just 20 times closer to its host star than Mercury orbits the Sun, making it vulnerable to destruction.
BD+05 4868 Ab has a mass less than half that of Mercury and is estimated to lose a Mount Everest’s-worth of material with every orbit. This process will completely dissolve the planet within 1 or 2 million years.
The discovery was made using the transit method, where astronomers observed periodic dips in brightness caused by the planet passing between its host star and a telescope. However, unlike other planets, BD+05 4868 Ab’s transits revealed a tail that doesn’t contain volatile gases and ice.
Researchers estimate that the planet may have started with more mass but has been losing material at an alarming rate due to its weak gravity. The team believes this is a runaway process that will lead to the planet’s disintegration.
This discovery offers scientists a unique opportunity to study the composition of a rocky planet using the James Webb Space Telescope (JWST). By analyzing the spectrum of the star’s light absorbed by the dust, researchers may be able to reveal what the doomed planet is made of and gain insights into the diversity and potential habitability of terrestrial planets outside our Solar System.
Source: https://www.sciencealert.com/this-melting-planet-laid-a-trail-of-destruction-over-5-million-miles-long