Kepler just can't stop discovering exoplanets. Nearly two years after scientists said it was crippled, the planet-hunting telescope recently identified eight new planets. But that's not all. They're all in the Goldilocks zone of their respective stars, and two of them are more Earth-like than anything astronomers have ever seen.


This is exciting. If you've been following mankind's planet-hunting pursuit, you'll know that the Goldilocks zone is that magical area around a star that's friendly to life as we know it. That basically means that planets in the Goldilocks zone get about the same amount of sunlight as Earth. Planets in this zone just might be habitable.

Astronomers have spotted planets in the Goldilocks zone before. In fact, some believe that one in five stars has a planet in the habitable zone. But two of the newly discovered exoplanets are special not just because they're in the habitable zone. They're also probably rocky, like Earth, and about the same size as our planet. The Harvard-Smithsonian Center for Astrophysics explains in a release:

The two most Earth-like planets of the group are Kepler-438b and Kepler-442b. Both orbit red dwarf stars that are smaller and cooler than our Sun. Kepler-438b circles its star every 35 days, while Kepler-442b completes one orbit every 112 days. With a diameter just 12 percent bigger than Earth, Kepler-438b has a 70-percent chance of being rocky, according to the team's calculations. Kepler-442b is about one-third larger than Earth, but still has a 60-percent chance of being rocky.


Could we live there? It's hard to tell. Astronomers can get a lot of information from the Kepler telescope, but these planets are too far away for close inspection—Kepler-438b is 470 light-years from Earth, and Kepler-442b is 1,100 light-years away. So if we really want to find Earth 2, we'd best keep looking. [Harvard]