Another asteroid shaves the Earth

By Phil Plait | March 17, 2009 10:39 pm
Artist drawing of an asteroid entering Earth’s atmosphere

I just saw on Universe Today that asteroid 2009 FH — a tiny thing, maybe 20 meters across — will pass the Earth at a distance of about 80,000 km, about 1/5 the distance to the Moon and well above our geosynch satellites.

The most recent numbers I’ve seen show that closest approach will be on March 18 at noon UT, just a few hours from now as I write this. It won’t get terribly bright, since it’s really small. It’s only about the size of a house, which is dinky as these things go.

People always ask what an asteroid like this would do if it hit us. Bear in mind this one won’t, but if something this size whacked us, it almost certainly wouldn’t reach the ground (unless it were an iron asteroid, which are less common than stony ones). Instead, it would burn up in our atmosphere, probably exploding several kilometers up. It might be big enough to generate a shock wave that could cause grief on the ground; recent work showed the Tunguska blast in 1908 was probably from a rock 30 – 60 meters across. So this one would do far less damage, because it would have had less than half the mass of that one at best.

So another one slips past us. Let me say this again: while things like this make most people more nervous, it actually makes me happier. It’s not that more of them are passing, it’s that we’re getting better at spotting them! And that means when the day comes when one of these big enough to do serious damage has us set in its crosshairs, we may know about it far enough in advance to do something about it.

CATEGORIZED UNDER: Astronomy, DeathfromtheSkies!
ADVERTISEMENT

Comments (35)

  1. It’s not that more of them are passing, it’s that we’re getting better at spotting them!

    Do you know how HARD it is to get people to understand that? I’m already hearing woo reports that the solar system is passing through a dirty section of space and the sun will get blocked out in (you guessed it) 2012… Sometimes I think it would just be easier to devise a way to ship off the stupid to one of these rocks, and just “forget” them there. Although, I worry what that would do to the mass of those rocks… Could make for quite the massive object. Especially considering how dense they are. 😉

  2. Brian

    It is good to hear that we really are getting better at spotting them. I might have otherwise assumed that we were just getting noisier at fretting about them. So to speak.

  3. IVAN3MAN

    @ Larian LeQuella:

    Sometimes I think it would just be easier to devise a way to ship off the stupid to one of these rocks, and just “forget” them there.

    In Douglas Adams’ The Hitchhiker’s Guide to the Galaxy, one alien race did something just like that to their undesirables, and their spaceship ended up on Earth — which is why we now have the same problems as those aliens once had!

  4. Totally messed up the program IVAN3MAN. And sadly, those guys died out from a disease spread by dirty telephone receivers. 😉

    Although, I think there is a huge difference between useless and wilfully (intentionally even) stupid. 😉

  5. I find it kinda thrilling. The Universe just chucked another rock at us and missed. *shakes fist in the air* “Ha, you missed us again cosmos!”

    Thanks for pointing to my article Phil, it was blind luck I found the lead to this story. For some reason I wanted to see what the asteroid situation was looking like and a close shave popped up on the JPL page :)

    Cheers! Ian

  6. IVAN3MAN

    Yes, you’re right, Larian LeQuella; it’s been more than seven years since I had last watched that TV programme. However, it’s still a good idea to send such undesirables into deep space, is it not?

    Well, I’m going back to sleep!

    zzzzzzzzzzzzzzzzzzzzzzzz…

  7. José

    Sometimes I think it would just be easier to devise a way to ship off the stupid to one of these rocks, and just “forget” them there.

    I know how to get funding for this. Just pitch it as a reality show. Call it The Witless Protection Program.

  8. Woof

    > it actually makes me happier. It’s not that more of them are passing, it’s that we’re getting better at spotting them!

    Nah, we know better: Close approaches by asteroids make for more book sales. 😉

  9. Tim G

    I think humanity could benefit from an impact event slightly greater than Tunguska provided that it occurs in a sparsely populated area and the residents are given ample time to evacuate.

  10. Charles Boyer

    We are getting better at spotting these near-earth objects, and the media has been trained to dutifully report each one as a close call for the Apocalypse.

    It’s been happening forever, and it will happen as long as the Earth is here. Yes, one will eventually hit us, but probably not today and probably not tomorrow.

    I put odds of a cataclysmic asteroid or comet strike as 1:1 with the super-volcano at Yellowstone erupting. Possible but odds are so low that they are relatively infinitesimal on any given day.

  11. MadScientist

    Oh goody. I thought the earth was getting too hairy and was resembling a neanderthal hippy. A shave is good. “A Close Shave” (Wallace and Gromit) is awesome.

    @Woof: I think you got it right; the BA never misses a chance to spruik his stuff. Come on and buy your copy of Death from the skies! Quick, before a supersonic space rock whacks you, or a black hole gobbles you up, or …

  12. Charles Boyer

    @MadScientist,

    If a black hole is about to gobble me up, I’ll have spaghetti as my last meal.

  13. MadScientist

    @Tim G:

    Want to help me write a research proposal to fund a study on the economic viability of climate astro-geo-engineering by diversion of space rocks to low-population land areas? My proposal for using nukes to set off volcanoes to inject large amounts of sand and sulfur dioxide into the atmosphere was laughed at – no one understands genius. It’s all very reasonable though – we only need one eruption about the size of Pinatubo every 2 years and global warming is no longer an issue. If we can set off a Tambora or a Krakatao that’s even better – we can go skiing in Guam. Anyway, I think the mention of nukes must have triggered a morbid fear and avoidance reflex. Space rocks might win though.

  14. Tim G

    @MadScientist

    I was actually thinking about the public becoming more aware of impact threats and of space in general than any climate effects but I suppose some dust kicked up could cool the earth just a bit and provide spectacular sunsets.

    Yes, no one understands genius.

  15. Todd W.

    The asteroid shaved Earth? So is this evidence that Bic or Gillette are manufacturing asteroids, intent on subject us measly humans to their intergalactic empire?

  16. Torbjörn Larsson, OM

    Well that is genius considering that you don’t need to target very well – space rocks hitting densely populated areas will actually decrease AGW faster.

    Though of course there will then be less persons admiring pure genius left, so even your everyday evil genius cum mad scientist would try to avoid that. BWA-HA-HA-hee-hee-hee [snort]!

  17. Charles Boyer

    @Torbjörn: as soon as you buy a white Persian cat, we’re going to fear you mightily. :-)

  18. ND

    Phil: “And that means when the day comes when one of these big enough to do serious damage has us set in its crosshairs,”

    Let’s hope that’s not tomorrow night!

  19. Let us all cheer NASA for executing inexpensive photography and capture missions to deeply understand these conveniently local visitors. It would be a fool’s mission to spend a $billion traveling to the asteroid belt when everything one could desire is closer than the moon.

    Asteroid 99942 Apophis will do a 20,000 miles altitude skimmer on 13 Friday April 2029. Bring it home! – for its next snuggle on 13 Friday April 2036 could be a keyhole-threaded hit (NASA News Release 08-103).

  20. Knurl

    @Charles Boyer “If a black hole is about to gobble me up, I’ll have spaghetti as my last meal.”

    SINNER!!!! REPENT!!!!!!!! :-)

  21. Jeff

    some past statistics:

    Asteroid diameter (meters)
    Frequency of earth impact
    Expected damage

    100
    Once every 1,000 years
    Would damage an area the size of a city or cause a moderate tsunami in ocean

    1,000 (1 km)
    Once every 100,000 years
    Would damage an area the size of a state or cause a large tsunami in ocean

    10,000 (10 km)
    Once every 100 million years
    Would create a dust cloud that would encircle earth and cause a “nuclear winter”

  22. @Charles Boyer “If a black hole is about to gobble me up, I’ll have spaghetti as my last meal.”

    SINNER!!!! REPENT!!!!!!!! :-)

    All Hail His Noodly Appendage!

    RAmen!

  23. Would we have the wherewithall to put a gravitational tractor in place next to a large space rock, given just a year before it was scheduled to hit us?

  24. To answer your question succinctly Chuck: NO! Not until one has already hit us. While scientists and astronomers know what it would take, the governments and people in general are only reationary. They won’t buy into an idea until it’s too late…

    @TheMadScientist, call me when you have your cat, I’ll gladly volunteer to be your #2!

  25. Quiet_Desperation

    It’s not that more of them are passing, it’s that we’re getting better at spotting them!

    Or maybe someone out there is calibrating something.

  26. dkary

    The only problem with visiting one that is passing really close to the Earth is this nasty thing called relative velocity: getting up to speed to meet velocities with something going past at several km/s can be just about as hard as traveling several AU to meet up with one.

  27. QUASAR

    Like I said in one my previous comments on another entry like this one, the biggest threats to humanity are right down here on Earth and given the big problems that we’re currently facing right now(you know very well which ones), asteroids don’t concern me very much!

  28. MadScientist

    @Larian LeQuella:

    That could be a long wait; I’m a dog person. I can often be seen crawling on all 4 and sniffing other dogs’ butts. It’s unlikely I’d be possessed to get a cat. I can get a hairless chihuahua I guess – that looks like a cross between a cat and a rat – it certainly doesn’t look like a dog. I once had a cat; except for killing the occasional mouse and eating the roaches he wasn’t of much use – he wouldn’t play tag and he brought out all his claws whenever he was wrestled.

    @Quasar: dead right; there are far greater threats on earth like drunks driving cars, the excessively greedy class of conmen known as CEOs, the biggest pyramid scheme of all (the stock market), and of course the acolytes of ignorance.

  29. IVAN3MAN

    MadScientist:

    [T]here are far greater threats on earth like drunks driving cars, the excessively greedy class of conmen known as CEOs, the biggest pyramid scheme of all (the stock market), and of course the acolytes of ignorance.

    Such as Jennifer Ann “Jenny” McCarthy.

  30. Torbjörn Larsson, OM

    as soon as you buy a white Persian cat, we’re going to fear you mightily

    Well, I’m a cat person, but not a Persian person. I like my significant others catty, not big-headed with runny eyes.

    That is from Dr. Evil, I presume?! Must see Mr “Mad” Mike Myers movies someday.

    Btw, did Mini-Me have a mini-Persian? Or at least a white rat?!

  31. Flymises

    @QUASAR + MadScientist:

    You are dead right in what you say but to conflate the issues is fallacious. None of the threats/risks you talk about or that we ‘currently face’ may cause the entire Earth to freeze over, or cause widespread, direct societal destruction as few-mile-wide meteor would!

    Sure, the risk is minute but VERY real (unlike, say, a Blavk Hole gobbling us up).
    To ignore this and to ignore potential greater efforts into protecting us from it is downright foolish!
    It’s just the kind of ‘idiot-human’ legacy that fits too well with our past human experimentations – there are two crucial differences with this little experiment, however:

    1) is that it could very really lead to our ultimate destruction.

    2) In the past, such passiveness was forgivable since we did not have the knowledge, but now we have much greater knowledge, are very aware of the threat and are the most technologically advanced we have ever been.

  32. Torbjörn Larsson, OM

    Flymises, I think the point is that our ultimate destruction by meteor is likely to happen after our likely destruction by other means, either individually or collectively. Or even by us collectively having evolved away hundreds of thousands of years hence, “having gotten our humanity/society destroyed” (evolved rather), for another long time perspective. Also on such perspectives, we know life likely will go on because it has weathered such events for a much longer time. So we shouldn’t be in “scare” mode, possibly not even in “threat” mode.

    But also that it is relatively easy and also constructive (learn a lot) to lower the risk appreciably, so we should do it anyway, sooner rather than later.

  33. Torbjörn Larsson, OM

    Btw, on that topic I’ve seen the plug that it will be the first threat that humanity has steered away from.

    [Not exactly true IMO, I read today that someone modeled what would have happened with the ozone layer if the world community hadn’t stopped fluorocarbons. Projected irradiation levels would have gone up 3 orders of magnitude in some UV bands in a century or so. Ouch! Then we also have lowered nuclear threat compared to before, as well as effectively exterminated smallpox pandemics.]

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+