I have had several people ask questions about this, so I figured it was time to blog it. On Monday, a meteor about 100 feet wide passed pretty close to Earth. Pretty close in this point is 40,000 miles (about twice as far away as geosynchronous telecommunication satellites). It was discovered merely two days before closest approach by Rob McNaught in Australia.
What would this type of object do if it were to hit Earth? Well, we have a pretty good idea since it is roughly the same size as what hit over Tunguska in 1908. Fortunately Tunguska is not very populated as the energy output is easily into the many megaton range (~10 megatons is a commonly cited figure). Not enough to wipe out life on Earth, but you sure don't want it to hit near a major city. It could easily kill a few million people if it were to hit a major metropolitan area.
These asteroids are small and dim. They are difficult to find as we don't have the telescopes to search the whole sky on a regular basis for the. That is changing. Pan Starrs, a series of four 1.8 meter telescopes in Hawaii, each with a 1.4 gigapixel camera, will be able to scan the entire sky about every four nights. Around 2014 or so, the Large Synoptic Survey Telescope, an 8.4 meter telescope to be build in Chile, will be able to image even fainter asteroids and scan the sky ever three nights.
Fortunately, we are looking for them and getting a lot better at finding them. I expect news of these near misses to become increasingly common (because we find more, not because they hapen more frequently!)
There is a group called the B612 Foundation working on the problem. Their ambitious goal is to alter the orbit of an asteroid by 2015. Contrary to the movies, blowing up a nuclear bomb isn't a good option. We want to be able to make sure the asteroid misses Earth and that it will continue to miss Earth in the future!
We are smart enough to find the rock with our name on it...and just about smart enough to do something about it when we find it.
Reprinted with permission from the Half-Astrophyscist Blog.
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13 comments:
"It was discovered merely two days before closest approach by Rob McNaught in Australia."
If we can't get any more warning, I don't want to know.
geosynchronous....don't you dare use that language with me, young man!
No swearing week! Sorry.
If we found something like this a few days in advance heading toward a populated area, you could get a lot of people to safety in that time. If we found it was going to hit the ocean, you may need to evacuate the coast as it could cause a tsunami. Either way, you have the potential to save thousands to millions of lives.
These guys that could do serious regional damage are the tough ones. Large asteroids that could wipe out all human life are, fortunately, easier to find so we are likely to have more warning. More warning means more opportunity to do something about it.
And I have to add a link to this comic from Savage Chickens that is related to the meteor discussion.
I heard (I think) that it was as big as a ten story building and if it had impacted the earth, could have caused a fireball and flattened as much as 500,000 acres.
Large enough astroids that could wipe out human life? Yikes. If we can't divert them, I don't want to know too much in advance either. All I want is enough time to get in a last steak dinner and then contact Zoltar to send over one of her "flaming hot" varieties! ;>
Heck, I want to know. There are folks I'd rather help to their ends than allow chance to do it.
On a more ominous note, I noticed we heard about this AFTER the event was over. I think if we were really going to get hit and they knew ahead of time, common man wouldn't know until impact.
Heavens...it will probably hit my home land of India.......everything chaotic seems to be happening there lately......oh me.
Huck, there as no conspiracy to keep it from the public. I heard about it within hours after it was discovered, well before it passed. The Sky and Telescope article I linked to was posted before it passed encouraging amateurs to try and image the asteroid. It was also featured on Spaceweather the day before it passed. If you want, you can subscribe to IAU circulars to get notified of these discoveries via email. Astronomers are pretty lousy at keeping secrets :)
I was listening to one of my guilty pleasures, the No Agenda podcast today. The two hosts were talking about Comet Lulin and bouncing conspiracy theories about why they had never heard of it before. I propose the reason they hadn't heard of it is that they are not astronomers. It was discovered in 2007 and the people who are likely to study it, knew about it.
Oh, and there is another one passing closer than the Moon on Friday...don't say I didn't warn you!
Oh, and kk, just curious...is this post getting a lot of hit? I have a nice spike in hits on the halfastro blog today due to this post.
Funny thing, hale... I almost posted something about that earlier. I was poking around this afternoon and I thought something was wrong, like I somehow had set a filter to only show this page and its page loads. Almost every recent load was landing on this page, coming from all across the nation. Yes, baby, you are quite the "hit" today!
What is this new one on Friday? Must we worry? Do I need to get in contact with Mme. Zoltar... may I, pretty please???
Oh, the one on Friday is slightly smaller (23 meters) and will pass about 200,000 miles away. No worries!
:) So, I can only justify the steak?
This blog made the first page of search results on CNN.com...and the JTI site is ABOVE mine...hey!
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