Skip to main content

Two rocky super-Earths discovered just 33 light-years away

Researchers using NASA’s Transiting Exoplanet Survey Satellite (TESS) have discovered two rocky exoplanets in a system in our cosmic backyard, located just 33 light-years from Earth. These are some of the closest rocky planets discovered to date, orbiting around a small, cool star called HD 260655.

The two planets are of a type called a super-Earth, at 1.2 and 1.5 times the size of our planet, but they aren’t habitable as they orbit close to their star and have high surface temperatures. According to NASA the nearest planet to the star, called HD 260655 b, has a surface temperature estimated at 816 degrees Fahrenheit (435 Celsius), while its companion HD 260655 c is estimated to have a temperature of 543 Fahrenheit (284 Celsius).

Related Videos
Illustration of two newly discovered, rocky "super-Earths" that could be ideal for follow-up atmospheric observations.
Illustration of two newly discovered, rocky “super-Earths” that could be ideal for follow-up atmospheric observations. NASA/JPL-Caltech

Estimating the surface temperature of exoplanets is tricky though because it depends on whether the planets have an atmosphere. In our solar system, for example, Venus is hotter on its surface than Mercury even though it is farther from the sun because its thick atmosphere traps the heat.

So to understand more about exoplanets, we need to measure their atmospheres — something which has historically been very difficult but will be possible with new tools like the James Webb Space Telescope, set to begin science operations this summer.

And these two planets are ideal candidates for studying exoplanet atmospheres, because they are relatively close to us and because the star around which they orbit is bright despite its small size.

“Both planets in this system are each considered among the best targets for atmospheric study because of the brightness of their star,” explained one of the researchers, Michelle Kunimoto of MIT, 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.”

Artist's drawing of a satellite exploring two super-Earths.
MIT astronomers have discovered a new multiplanet system that lies just 10 parsecs, or about 33 light-years, from Earth, making it one of the closest known multiplanet systems to our own. The star at the heart of the system likely hosts at least two terrestrial, Earth-sized planets. MIT News, with TESS Satellite figure courtesy of NASA

James Webb will be able to investigate exoplanet atmospheres by looking at the light which shines from a star and passes through a planet’s atmosphere. By splitting this light into a spectrum, researchers can see which wavelengths have been absorbed by particular molecules, and that allows them to work out what the atmosphere is composed of.

There’s no indication yet on whether these two newly discovered planets have atmospheres or not, but they are exciting targets for further investigation.

The research was presented at the meeting of the American Astronomical Society on June 15 and will be published in the journal Astronomy & Astrophysics.

Editors' Recommendations

Researchers discover planet in the habitable zone of an ultra-cool star
The telescopes of the SPECULOOS Southern Observatory gaze out into the stunning night sky over the Atacama Desert, Chile.

Even though we've discovered over 5,000 exoplanets, or planets outside of our solar system, most of these aren't very Earth-like. They're often much bigger than Earth, being more like gas giants Saturn and Jupiter than small and rocky, and relatively few are located in the habitable zone where liquid water could exist on their surface. That's why it's exciting when a planet comparable to Earth is discovered in its habitable zone -- as one such recently discovered planet is.

Researchers looked at a planet called LP 890-9b or TOI-4306b, previously discovered by NASA's Transiting Exoplanet Survey Satellite. Using a ground-based telescope called SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars), they studied the planet which is around 30% larger than Earth and orbits extremely close to its star, with a year lasting just 2.7 days.

Read more
Astronaut reveals source of ‘intriguing’ bright light on Earth
The bright light of a solar power station as seen from space.

Peering out from the International Space Station 250 miles above Earth recently, European Space Agency astronaut Samantha Cristoforetti spotted an “intriguing” bright light in the middle of a desert.

Sharing several photos of the strange sight, the Italian space traveler noted how unusual it is to see a bright spot like this in the daytime.

Read more
This galaxy is a mind-bending 13.5 billion light-years away
A zoom-in image of galaxy HD1.

The universe is a bit less than 14 billion years old, and because light takes time to travel, looking far enough away is like looking back in time to the start of the universe. Recently, an international team of astronomers identified the most distant astronomical object ever observed: A galaxy 13.5 billion light-years away, which formed just 300 million years after the Big Bang.

The galaxy has been named HD1 and identifying it required considerable patience and the use of four different telescopes -- the Subaru Telescope, VISTA Telescope, UK Infrared Telescope, and Spitzer Space Telescope -- with a total of more than 1,200 hours of observations. The distance to the galaxy was confirmed using another instrument, the Atacama Large Millimetre/submillimetre Array (ALMA), which is an array of 66 radio telescopes working together in Chile.

Read more