A research team led by astronomer Jonathan Swift has estimated that the Milky Way galaxy contains somewhere between 100 and 200-billion alien planets, at least one of which is capable of supporting human life without spacesuits or us having to create massive atmosphere processors or something. Which is a good thing, because at our rate of destruction and consumption in the past five million odd years since humans have been about (f**k off with your few thousand years Creationists) we’ve killed, consumed, destroyed and blew a lot of stuff up. Probably a good idea to have an exit strategy:
How did Swift and company arrive at this conclusion? By studying the makeup of a planetary system designated Kepler-32, located about 915 light-years from Earth. The system includes five planets, all closely orbiting an M dwarf, a type of star smaller and cooler than our own sun. The planets are very similar to other exoplanets found orbiting other M dwarfs in the past, which made Swift and his colleagues suspect a trend.
About 75 percent of the Milky Way’s 100 billion or so stars are M dwarfs like the one in the Kepler-32 system, and the researchers believe many of the other M dwarfs in the galaxy may also host one or more planets. Because the Kepler telescope operates by detecting when a star dims as a planet passes in front of it, it can only see planets from a certain angle, so the researchers calculated how many of the galaxy’s M dwarf stars would be at the right angle to show their planets to the telescope. After all that calculation, Swift and company arrived at the 100 billion number.
Stephen Hawking has often spoken of the vast expanse of the Universe, never mind our pebble of a Galaxy, so it’s not really that surprising that we’ve got a sh*t load of planets next door that we formerly didn’t know about, seeing as how, well the Universe is absolutely massive.
“It’s a staggering number, if you think about it,” Swift said. “Basically there’s one of these planets per star.”
The M dwarf stars are considerably cooler than our sun though its viable that even planets orbiting relatively close to these could be habitable, and indeed it seems the Kepler-32 planet orbiting furthest from the star (still much closer than Earth is to the sun) is in the habitable zone. Which means that one in five planets in that system is habitable. There’s an additional 200 billion out there which could also thus be habitable, so lets just say when the shizz hits the fan; we’re invaded by Giant monsters or accidentally engineer the apocalypse – presuming we have some form of space travel then we got options.