Saturday, April 4, 2009

looking for other earths

astronomy nova scotia drew another packed house on a friday night last night at smu. this time, we were there to get an update on space from ray jayawardhana, an astrophysicist from the u of t.

he was in fine form, bouncing around the podium in his enthusiasm to bring us the latest from the final frontier - and i mean latest, like things being discovered in march and things being searched for this month. he had a laser light to use as a pointer for the powerpoint, but the little green light spent more time shining in his face as he excitedly used his hands to show us how different planets interact with different stars.

i interviewed ray a little while ago for my culture corner column and have rather lazily pasted it in below.

what amazed me most last night was the ingenuity people used to make the best of our limited technology. we can't get to distant stars, so we build telescopes to see them. we can't see distant planets, because they disappear in the starlight, so we look for how they affect the movement of the stars, and how when a planet passes in front of a star, it dims it.

most of the extra-solar planets discovered so far have been huge, jupiter-like gas giants in close to their stars. this could make you conclude, therefore most planets outside of our solar system are jupiter-like giants near their stars, but no. it's just easier to see giants, and when they're close to their stars, they spin around them every few days, giving us a better chance to observe them. jupiter itself only goes round our star every 12 years, meaning you'd basically have to stare at empty space for 12 years to see it once, and 24 years to see it twice. so, with time, as our astrophysicists stare at empty space for a few more decades, we will find more smaller planets further from their suns - in the 'habitable zone' where we know from our earthly experience that life can form.

The 2008 UFO survey released last month by Winnipeg’s Ufology Research reported a record-high 1,004 “sightings” in Canada. Nova Scotia had a record high of its own, with 34 unidentified flying objects spotted.
This citizen science mostly consists of people glancing up, being stumped by something in the sky, and firing off an e-mail. About 90 per cent have been explained and less than one per cent of “high quality” reports have yet to find a non-alien explanation.
For some star-gazers, this lazy approach to finding other life in the universe won’t do. Ray Jayawardhana, astronomy and astrophysics professor at the University of Toronto, approaches the job with hard work and hard science.
“It’s one of the most exciting areas of astrophysics: the discovery of extra-solar planets. People have talked about finding planets for centuries, if not millennia, and finally in 1995, astronomers made the first definitive discovery of planets around another star,” the Discovery Channel expert says from his Ontario home.
Since then, we have found more than 300 planets.
“It’s an incredibly dramatic progress. Stunning discoveries are announced almost every month now.”
So far, we’ve mostly found gas giants similar to Jupiter, which aren’t hospitable to life as we know it. Some are just tens of light years away while others are halfway to the centre of the galaxy. As our machines improve, we will find smaller, more stable planets.
“In the next three or four years, there’s a pretty good chance that astronomers are going to find more Earth-like worlds, which raises the question of habitability and life out there,” Jayawardhana says. “If they have more massive rocky planets in other solar systems, they may actually be even more hospitable to life than the Earth itself.”
That’s because the big, rocky worlds would have plate tectonics, like ours does. The gigantic grinding of the planet stirs the primordial soup, making life more likely.
While the Mulders of the world tear apart the shadows, Jayawardhana & Co. are busy casting light. If the little green men turn up, I’m guessing it’s Jayawardhana who will see them coming.
Jon Tattrie is a journalist and writer in Halifax. Black Snow, his first novel, is now available at The Book Mark on Spring Garden Road or via
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