NASA's TESS exoplanet fighter telescope has been at work for less than a year, but is already amassing some impressive discoveries. Following the announcement of a new "Hot Saturn" in March, NASA has just revealed that TESS found its first Earth-sized planet outside our solar system.
The TESS – an acronym for Transiting Exoplanet Survey Satellite – is designed to detect the exoplanet indicator signals orbiting the observed stars, noting the small changes in brightness associated with a planet passing in front of them. This last observation is actually the 10th confirmed planet that TESS has discovered, but it is the first that is probably close to Earth in general size. Still, you definitely would not want to go there.
The Earth-sized planet, called HD 21749c, is estimated at about 89% of Earth's size, and orbits a star that is about 70% as large as our Sun. However, very little about the planet's relationship and its star is like the earth. The finding is described in detail in a new article published in Astrophysical journal letters.
A year on the planet lasts less than eight Earth days, suggesting that it is incredibly close to the star. This close relationship means that the HD 21749c is absolutely hot, and researchers estimate that its surface is probably around 800 degrees Fahrenheit, or about 427 degrees Celsius.
The planet and its star are not particularly distant. It is believed that the HD 21749 is only 53 light-years away, which means it may be possible to study it and its hottest planet in even greater detail.
HD 21749c is not the kind of place where we would expect to find life as we know it, so alien hunters will need to look elsewhere, but the discovery of any planet outside our solar system is still undeniably interesting. In the future, new discoveries of exoplanets by TESS must continue, so it should not take long for NASA to find a world even more similar to ours.