There is so much interesting stuff happening here, but one in particular happening in the building next to mine is very, very interesting.
The headquarters of Kepler is here at Ames. Now Kepler is a NASA planet hunter telescope and you can imagine it being like a next gen Hubble telescope. It's in space, huge, but a lot more advanced.
Unlike the Hubble, which rarely looks at an object for more than a week, Kepler’s field of view of millions of stars never changes.
From what is known of the formation of solar systems it thought that there should (no-one knows yet) be planets around nearly every star. And not just one or two, but a whole multitude like in our system. Roughly 300 hundred planets have been found around other stars in other experiments (the Hubble even managed to take a photo of another planet), and the largest number of planets found around 1 star is 5. Of course no one yet knows if these are huge exceptions to the rule, or not.
Stars come in a variety of sizes and the bigger they are the faster and hotter they burn. The biggest stars only last for a few millions of years, and as it took a couple of billions of years for the Earth to form there’s no point looking at the biggest stars. The Sun though is about half way through its 10 Billion year life and due to the fact we’re here and even able to look suggests stars of a similar size are a pretty good place to start looking.
Therefore Kepler is looking at 200,000 stars simultaneously that are roughly the same size as ours.
There is a partular zone around a star called the 'goldilocks' zone. It sounds ridiculous but if a planet is orbiting in this zone it shouldn't be too hot or too cold for liquid water to exist on the surface. Why this is important is that wherever you find liquid water on Earth you find a perlephera of life. Earth you'll be unsurprised to find is slap bang in the middle of this zone.
Kepler then is hoping to see an Earth sized planet orbiting a Sun sized star in this zone.
What Kepler is looking for is a slight dimming of these stars due to a planet crossing in front of it. This dimming is in the order of 20 parts per million. It’s like trying to see a glow fly in front of a car's full beam headlights from 10 miles.
But this telescope can do it. Not only that but before they launched NASA weren't sure exactly how good precise it would be but they've found that it is able to see 5 parts per million. This is easily low enough to see an 'Earth' size planet.
It's only been working for two month and they've already seen hundreds of planets, and even one only twice the size of the Earth that orbited in the Goldilocks zone. Why they only 'think' they've seen this is that a planet like the Earth orbiting at roughly the same distance as us from its star will have an orbit of about a year as well. This means that it will be another year before they can confirm it. They even think they've also seen a planet smaller than the Earth so hopefully seeing a new Earth will be possible.
And it really is as simple as that. Once a month they get a download from the telescope and each time they do there is a higher chance of seeing a new Earth. Everyone is very excited about it .
What Kepler should also be able to do is detect reflected light off any atmosphere the planets might have. What this might mean is that the people here might be able to see what elements the atmosphere is made up off i.e. look for methane, co2, or carbon hydrogen chains, all pretty good clues for life!
Kepler has also discovered a planet orbiting a binary star system. 45% of systems are binary (two stars orbiting very closely to each other) and a scientific paper ten years ago 'proved' that planets wouldn't be able to form
around them. The fact they can further increases the chance of finding these new Earths. I asked the guy runnig the show (he came to our house for a barbecue) how many Earths he thought they'd find. If they were very pessimistic with their models they predicted they see about 50, but from what they'd seen so far he thought maybe more like 500. Some computer models gave a figure of 2000! And don't forget that Kepler is only looking at 200,000 stars and the galaxy is made up 100 billion stars (100,000,000,000). There might be quite a few earths out there.
Well I really must go as my boss just came in and saw that I was obviously not working.
All the best,
P.s. Sorry for the essay!
Fascinating stuff. Don't apologise for the essay Harry, write a book, or be a teacher. You've got a good touch. Tom
Posted by: Tom | September 14, 2009 at 01:04 PM
Fascinating I must say. Don't apologise for the essay Harry, write a book, or be a teacher. You've got a good touch. Tom
Posted by: Tom | September 14, 2009 at 12:59 PM
cool! perhaps we can find another one to muck up! xxxxxxx
Posted by: camilla | September 12, 2009 at 01:40 PM
Harry - Fantastic updates from tomorrows world(s) keep 'em coming
Posted by: Paul | September 12, 2009 at 12:34 PM