A planet roughly 2.4 times the size of Earth has been discovered orbiting its star in the “life zone” or “habitable zone.” Found by NASA’s Kepler mission, the planet is in a solar system approximately 600 light-years away.
The “life zone” is the sort of “sweet spot” around a star that is neither too hot nor too cold for water to exist in its liquid form, and consequently, for life as we know it to thrive on any planets that may be in that region. The star in the system is G-class star, like our own, but a little bit smaller, so the life zone around it is about the same region as the distance between the orbits of Venus through Mars, as illustrated in this diagram here.
The planet, thus far only referred to as Kepler 22b, is almost 2 1/5 times the size of Earth, and orbits its star a bit closer than Earth does, but having passed this first investigatory hurdle, astronomers will be studying it even more closely to try to determine what manner of planet it may be. As of yet, they do not know whether it is terrestrial (made of rock and soil like Mercury through Mars), covered in liquid (like Uranus and Neptune), or composed of gaseous clouds (like Jupiter and Saturn).
For more information please call 229-432-6955. Credit: NASA. Image credit: NASA/Ames/JPL-Caltech.