Hey, sky fans! This time, that exclamation point is certainly in order, and has nothing to do with caffeine. The big news out of the cold and empty today, and probably all week, comes from NASA’s Kepler observatory, which spends its time staring at the same spot of the galaxy looking for exoplanets — planets orbiting other stars — as it orbits the Sun from a point that’s about 75 million miles away from the Earth at the moment. If you remember, a couple of weeks back, Kepler fell into emergency mode, and was recovered a short time later.
Well, today NASA announced that it has confirmed, hold onto your Boötes, 1,284 newly validated planets, which more than doubles the number of planets that were previously verified (more info here). Nine of the exoplanets announced today are in the habitable zone, sometimes called the Goldilocks zone, of their parent star. That means they’re not too hot and not too cold; the temperatures are just right for liquid water to exist. Here, back home, where there’s water there’s life, so, who knows?
Kepler finds planets using what’s called the transit method. It stares at the stars in the same area of the sky. When something, perhaps a planet, passes in front of one of these stars, as Mercury did the Sun yesterday, there’s a slight but noticeable dip in the amount of light Kepler sees from the star. The transit method only works for finding planets when the the star system is oriented more or less edge-on as seen from Earth. If it’s not, the planet will always pass to one side or the other of the star and Kepler will never see it.
That’s what makes these discoveries even more incredible. It’s only planets at stars in this small region and that are oriented just right. Anything that is in a different area, or is tilted too far turns up nothing from Kepler. Yet, it’s confirmed over 2,000 exoplanets. Amazing. And this doesn’t even the planets found by observatories that aren’t Kepler!
When I was a kid, I had a map of all of the known planets in the universe on my bedroom wall. They were all within about three billion miles of that map. Back then, we knew there were nine, not eight (or… maybe nine) planets. We knew Jupiter had 16 moons and we knew Saturn had 12. There was only water on Earth, and there may as well have been a giant Plexiglas wall just past Pluto. The stars were far-off and isolated. In 1992, that all changed, and now… imagine how big that map could be now, and how much water would be drawn on it.
These are incredible times. The speed at which we’re finding, and finding out, new things seems to be the only thing faster than light. Who knows what’ll be next? On nights like these, it seems like all there is to do is stand outside, look up, wonder, and wave. Clear skies everyone.