This evening I attended another of the UofA's night time, free, public Astronomy lecture series. Dean (poor Dean!) is working evenings this week, and wasn't able to attend. I was, however, joined by our friend from Saskatchewan, Ed, who is in town for the next couple of weeks. This evenings topic was the Catalina Sky Survey, which is done from the observatory on the top of our local Mt. Lemmon. Ed Beshore (co-Investigator), of the Catalina Sky Survey (CSS) was the featured speaker, and gave a most interesting talk. The CSS is (in a nutshell) surveying the sky, along with two other observatories, searching for asteroids big enough to cause catastrophic damage should they impact the earth. There is evidence of such an impact occurring some 65 million years ago, in the Yucatan Peninsula of Mexico. The damage attributed to that impact is suspected to have caused the extinction of the dinosaurs. There is evidence that the impact was significant enough to cause a thin iridium layer to be found, virtually, every where on our dear planet Earth; and it is suspected that it blew debris out as far as our Moon. So, the value of searching for asteroids the size of cruise ships that may "hit home" is significant, to say the least! Granted, you can observe and search - but how do you know you're right? The CSS got the 'confirmation' that it needed last fall, when Asteroid 2008TC3 hit Sudan. The CSS had discovered the asteroid, determined that it would impact the Earth, predicted when it would hit and it was observed impacting the Sudan desert as predicted. Furthermore, it was just announced (in the past few days) that an asteroid fragment had been found and recovered at the site! Granted, what was left is the size of a large shooter marble and damage was nil. However, picture "The Love Boat" tumbling through the atmosphere with your house in it's site. It would be nice to know in advance. You can't 'plan' a test of the survey, it was by chance that it all came together with 2008TC3 and the Sudan. Interestingly, between the three observatories (Mt. Lemmon/Mt. Bigelow; Palomar Observatory in California; and Siding Spring Observatory in Australia), they are able to do a deep survey of the entire sky once a month. The Steward Observatory Mirror Lab (Dean and his work buddies) are currently creating the 8.4 meter mirror for the new LSST (Large Synoptic Survey Telescope). I know that Dean has blogged about that telescope in previous posts, but it bears repeating. Once completed and running, the LSST will be able to do a total deep sky survey every three days. Incredible! It's nice to know that someone is 'watching our backs', as they say!
(Photos courtesy of the CSS website - please visit their site for pictures, videos, and news releases.)
Addendum: Rest assured, we have no reason to believe that Asteroid 124075 Ketelsen will ever pose a serious threat to our fragile blue planet.
Monday, March 2, 2009
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