Possible Earth Sized Planet Confirmed

On April 17th 2014, NASA announced that the Kepler space telescope had discovered a planet about the size of the Earth orbiting a distant star. The planet, named Kepler-186f orbits an M-type dwarf star some 490 light years away. What is unique about this particular planet is that it is the first Earth sized planet that orbits its star in what is know as the "Goldilocks," or habitable zone.

The habitable zone is the area around a planet's star where the temperature is not too hot and not too cold, but just right to find liquid water, which is essential for life to form. Kepler-186f inhabits an orbit that would be similar to that of Mercury, here in our own solar system. But, since its star is an M-type, or Red dwarf star, the heat it emits is about a third of that of our sun. It is believed that Red dwarf stars make up 70% of all of the light we see in our own Milky Way.

Though Kepler-186f is slightly larger than the Earth, about 1.5 times its size, researchers feel that it is small enough to be a rocky planet just like the Earth. This is significant because most of the planets that have been found orbiting other stars have been extremely large. Finding smaller, rocky, earth like planets in the habitable zone could mean that these planets may also possess water.

There is still much research to do. It is not yet known what the planet's mass is, what elements it's composed of, or whether it has an atmosphere. While life needs water, it also needs a favorable atmosphere such as the Earth's oxygen, nitrogen, and carbon dioxide, which has proven necessary for maintaining and supporting that life. The type of atmosphere it has would also help to determine whether Kepler-186f  is either too warm or too cold to support life, as we know it.

While it's too soon to say for certain, this discovery could possibly be the first of many. If that is found to be true, then Earth like planets orbiting stars similar to our own, in their habitable zones, may be common not only in this galaxy, but throughout the universe. That might mean that the possibilities for finding life would not be restricted to our own little corner of space time.