Remember the other day, when we told you that scientists had found some potentially habitable planets hiding in Kepler data? Well, scientists have found 18 more – and they're just as important.
Scientists led by Guillermo Torres from the Harvard-Smithsonian Center for Astrophysics re-analyzed some data from the Kepler space telescope to confirm some of its candidate planets really existed. These are known as Kepler objects of interest (KOIs). The research is available on arXiv.
Importantly, most of the planets are not only similar in size to Earth, but also orbit in their star's habitable zone where liquid water could exist.
“These are not the first small planets in the habitable zone, but they are important because they increase the sample of such objects, which is important for statistical studies that aim to tell us how common these planets are in the Universe,” Torres told IFLScience.
Of the 18 planets, 15 have a confidence level of 99.73 percent that they exist. The others are slightly lower. Almost all of them orbit M dwarf stars, or red dwarfs, so they're not quite the same as us. The planets range in size from 0.8 times Earth’s radius to 2.76, and have orbits ranging from 18 Earth days to almost two years.
Five of the planets definitely orbit in their star’s habitable zone, and of those, two have a greater than 97 percent chance of being similar in size to Earth. They are KOI-2626.01 and KOI-4036.01. Another, KOI-2418.01, is definitely similar in size to Earth, and most likely orbits in its star’s habitable zone.