Astronomers from MIT have discovered a planet about 140 light-years from Earth that is rapidly crumbling to pieces, shedding massive amounts of surface minerals into space. The planet, dubbed BD+05 4868 Ab, has a mass similar to Mercury’s but orbits its star much closer, resulting in temperatures of up to 1,600 degrees Celsius.
The team used NASA’s Transiting Exoplanet Survey Satellite (TESS) to detect the planet and noticed a peculiar transit signal with varying depth every orbit. This signature is characteristic of a comet-like tail of debris. Scientists estimate that the planet loses about one Mount Everest’s worth of material during each 30.5-hour orbit, which will likely disintegrate within 1 million to 2 million years.
The researchers believe this tiny, low-mass planet lacks sufficient gravity to hold onto its atmosphere, leading to a runaway process of mass loss and further weakening its gravity. With only three other disintegrating planets detected beyond our solar system, BD+05 4868 Ab has the longest tail and deepest transits among them.
The discovery provides an opportunity for further observations using NASA’s James Webb Space Telescope (JWST), which can help determine the mineral makeup of the dust tail by analyzing infrared light absorption. The researchers plan to conduct further studies on BD+05 4868 Ab, including searching for signs of other disintegrating worlds in TESS data.
The team’s findings offer insights into the diversity and potential habitability of terrestrial planets outside our solar system, as well as the unique characteristics of these exotic objects.
Source: https://news.mit.edu/2025/astronomers-discover-planet-thats-rapidly-disintegrating-producing-comet-tail-0422