NASA’s Kepler spacecraft has found at least eight new exoplanets. These exoplanets are located near the zone of their stars, and at least two of them are similar to Earth.
Those planets, which are similar to Earth, are Kepler-438b and Kepler-442b. Both these planets are revolving around dwarf red stars, which are cooler and smaller than our sun. The Kepler-438b has a diameter that is 12% bigger than Earth’s and has a 70% chance of being rocky. Meanwhile, Kepler-442b is about one-third larger than Earth and is 60% rocky.
Astronomers believe that the planets are circling their stars in the habitable zone. The habitable zone is a narrow zone in which temperatures are mild enough to allow liquid surface water to exist. Also in this zone the planet is neither too hot nor too cold and receives as much sunlight as Earth. This zone is also called the ‘Goldilocks zone’.
Kepler-438b receives about 40% more light than the Earth giving it a 70% probability of having a habitable zone. Kepler-442b gets about two-thirds as much light as Earth and is 97% likely to be in the habitable zone.
Dr Guillermo Torres, from the Harvard-Smithsonian Center for Astrophysics in Cambridge, US, and the lead scientist of this find, said, “We’re not claiming they’re inhabited. For our calculations we chose to adopt the broadest possible limits that can plausibly lead to suitable conditions for life.”
None of the planets are close to our solar system. Kepler-438b is located 470 light years away from Earth, while the Kepler-442b is 1,100 light years away.
However, these new planets are too far away to be examined directly for any signs of life, even with the next generation of giant Earth and space-based telescopes. They’re also too distant for their existence even to be confirmed with 100 percent certainty. Kepler does its work by looking for a slight dimming of a parent star as a planet passes in front of it.
Co-author Dr David Kipping, also from the Center for Astrophysics, said: “We don’t know for sure whether any of the planets in our sample are truly habitable. All we can say is that they’re promising candidates.”