The newly discovered and confirmed exoplanet Kepler 22-B has made big news lately. Why? Well, it's the first confirmed exoplanet discovered by the Kepler space telescope that is roughly the size of Earth and sits in the habitable zone of it's host star! Now don't get too excited, this doesn't mean we've found Earth's twin, or that aliens exist. Being in the habitable zone doesn't imply that life actually exists there, it just means that the planet is the right distance from the host star such that it could harvest liquid water, if any exists in the system.
Artists impression of Kepler 22-B
The star, Kepler 22, is very similar to our sun in size and composition. The planet, Kepler 22-B, is about twice as large as Earth, and sits a little bit closer to its host star than Earth does to our sun. Astronomers don't yet know anything about the planets structure or composition. Due to its size and proximity to its host star, it's likely that the planet is rocky, but we need more information to confirm that. We also need more observations to see if the planet has an atmosphere and ,if it does, what that atmosphere is made of. One thing we must also keep in mind is that this system is 600 light-years away! At the speed of the space shuttle, it would take over 10 million years to get there! So all these news stories that suggest traveling to this planet are quite optimistic to say the least. Regardless, this is an amazing discovery, and astronomers expect to discover more planets like this in the near future. Could Kepler 22-B be very similar to Earth? Is there an alien species there? Only time will tell!
Credit: NASA/Ames/JPL-Caltech
