MIT experts find two Earth-like exoplanets in multiplanet system just 33-light years away

Astronomers at the Massachusetts Institute of Technology (MIT) have discovered a new multiplanet system located just 33 light-years from Earth. First identified by NASA’s Transiting Exoplanet Survey Satellite (TESS), this system has two Earth-sized planets around a small and cool M-dwarf star, named HD 260655. However, these rocky worlds are likely to be unhabitable because they orbit their star in a tight orbit, making their temperatures impossible to sustain water. 

So what's so special about these planets?

Scientists are excited about this discovery because this planetary system is one of the closest ones within our galactic neighbourhood. In addition to this, the proximity and brightness of the dwarf star would allow the astronomers to take a closer look at the planets and determine if they have any atmosphere.

"Both planets in this system are each considered among the best targets for atmospheric study because of the brightness of their star," Michelle Kunimoto, a postdoc at MIT and member of the discovery team said in a statement.

"Is there a volatile-rich atmosphere around these planets? And are there signs of water or carbon-based species? These planets are fantastic test beds for those explorations."

According to the experts, the inner and smaller planet is twice as massive as the Earth whereas the outer planet is about three Earth masses. On the other hand, the smaller one is slightly denser than the Earth, while the outer, larger planet is a bit less dense, however, both of them are getting roasted at 436°C and 286°C.

How are exoplanets discovered?

The two Earth-like planets were first discovered in October 2021 when Kunimoto, who is also a member of MIT's TESS team noticed dips in starlight emerging from the white dwarf. TESS, which is basically a space telescope, has been designed to discover exoplanets by looking for dips in light emerging from stars. This method helps because if a star has planets around it, and when the planets cross or transit the star's face, they would block the starlight occasionally causing fluctuations. Scientists look for these fluctuations and determine if there are planets around a star.