April 21, 2014
A New Earth
Does anyone else out there remember the animated film Titan A.E.? When I was younger, I loved that movie. Heck, I still love that movie. Even now it holds up pretty well as a well-designed, fun, science fiction flick. So, for those who are not in-the-know about the film, here is a basic rundown: the planet blows up. No, this is not really a spoiler, as this happens in the first five minutes of the film. So, yeah, Earth goes boom and humanity is left to seek out a new home. Titan A.E. is the story about what happens next, which is an interesting question to ponder. If something were to happen to our home planet, what would happen to us? Humanity is both proud and stubborn, so I find it unlikely that we would just go quietly into the night. What other worlds are out there that might be suitable to be a new home? Where would we go?
Well, one possible answer is Kepler-186f, a recently discovered planet that is both Earth-sized and exists within that solar system’s habitable zone, that being a distance far enough from the sun that water is able to exist in liquid form, yet not so far that it is too cold to potentially support a functioning ecosystem. The discovery was made using the Kepler Space Telescope and then confirmed using the W. M. Keck Observatory and the Gemini Observatory.
The Kepler Space Telescope, or any other telescope for that matter, is not currently able to directly spot an exoplanet of such a small size – and yes, Earth-sized planets are considered small – at such close proximity to its star. What can be done, however, is to eliminate all other known possibilities of what it might be so that being able to identify it as a planet is the only remaining viable option. What the team did in this case was use the Gemini North telescope to attain extremely high spatial resolution observations using a technique called speckle imagining, and adaptive optics (AO) observations from the Keck II telescope. Using these, they were able to eliminate the possibility that Kepler-186f might just be a background star or a stellar companion, both of which could mimic what Kepler initially detected. These two telescopes were able to rule out those possibilities and confirmed that what Kepler found was indeed a small planet in an orbit around its host star. According to Thomas Barclay, a Kepler scientist an a co-author of the paper announcing the finding of Kepler-186f, “The observations from Keck and Gemini, combined with other data and numerical calculations, allowed us to be 99.98% confident that Kepler-186f is real.”
Kepler-186, the star around which Kepler-186f (hopefully it will soon be given a more simple moniker) orbits, is an M1-type dwarf start that is relatively close to our own solar system. It is about 500 light years away from us and is in the constellation of Cygnus. Kepler-186f shares its solar system with five other planets, four of which have very short-period orbits and are very hot.
A truly remarkable discovery.
Image Credit: NASA Ames / SETI Institute / JPL-CalTech