Taking asteroids seriously

By Phil Plait | December 9, 2008 10:21 am

Asteroids are sexy again.

Sure, in 1998 we had two blockbuster movies ("Armageddon", which sucked, and "Deep Impact" which was excellent) showing us that asteroid and comet impacts could generate giant tsunamis, wipe out all life, cause lots of quick-cut camera shots, make Ben Affleck cry, and so on, but in the intervening years they haven’t gotten as much attention. There have been documentaries on TV and some coverage in the dead tree media, but that’s about it.

Artist drawing of an asteroid entering Earth’s atmosphere

But in the past couple of weeks there’s been a resurgence of interest. Of course, having three big, bright fireballs lighting up the skies recently didn’t hurt: the one in Darfur months ago, or the one in Canada weeks ago, or the one in Colorado the other night (which I missed, dagnappit!). Maybe it was the publishing of a brilliant book with a whole chapter dealing with asteroid impacts. Hard to say.

But most likely it was the reporting on findings from panels of top-level scientists on the topic that’s caused a mini-flurry of stories. The BBC news had a story on it just the other day. They interviewed Professor Richard Crowther, chair of the UN Working Group on Near Earth Objects (NEOs); and as you might expect, his conclusion was that we need to get off our asteroids and do something:

The document says most asteroids entering the Earth’s atmosphere are small and burn up before reaching the surface. But it is the larger ones – perhaps 200m or more across – that would need to be deflected away from a collision course with the Earth.

Even a rock 50 meters across could take out a city, exploding high in the atmosphere and generating a devastating shock wave and fireball. But it’s literally impossible to find asteroids that small very long before impact. 150 meters or so is a reasonable size to find, and that’s also about the size where they start doing damage on a large scale.

The UK newspaper The Guardian also picked up on this story, talking about (what I think is) a different group called the International Panel on Asteroid Threat Mitigation:

The international community must begin work now on forging three impact prevention elements – warning, deflection technology and a decision-making process – into an effective defence against a future collision,’ said the International Panel on Asteroid Threat Mitigation, which is chaired by former American astronaut Russell Schweickart. The panel made its presentation at the UN’s building in Vienna.

This is an important point, We need to find these suckers, we need to understand what to do, and we need to understand how to do it. Think of it this way: we find an asteroid 300 meters across, and calculate it will hit in Germany. Uh oh! So we launch a rocket, use our tech, and push it out of the way… kinda. Something goes wrong, and it only gets nudged. We recalculate the path… and find out it will now hit Pakistan. Oops! Their government might be a little ticked over such a thing, so we need to have some sort of process in place to deal with these (fairly realistic) issues.

I’m glad that scientists are able to get their reports out to the public, and I certainly hope the UN takes the threat seriously — they will meet in February to discuss the issue. This is a global problem, and needs to be dealt with on an international scale.

CATEGORIZED UNDER: Cool stuff, DeathfromtheSkies!

Comments (41)

  1. Francis

    Phil, don’t know why you thought that Armageddon sucked and Deep Impact was excellent – the former was a lot more entertaining, and both were full of scientific inaccuracies. At least Armageddon didn’t try to pretend it was anything but a popcorn movie.

    And in Deep Impact isn’t there a scene where Vanessa Redgrave manages to get a taxi when the world is expected to end in a couple of days? That is what I call dedication to your job!

  2. Beachmaster

    Sorry but the money would be better spent on clean water and simple medicines for the millions suffering right now. We can gamble that the big one is a few decades in the future, the last large hit was just 100 years ago. I say we save millions now and take the odds that a space danger is in the far future.

  3. tacitus

    I’m glad they’re taking it seriously, though in the grand scheme of things, I’m not too concerned about killer asteroids. The thing is, they won’t be a threat for much longer. By the end of this century or not long after, it’s almost certain that we’ll be able to track just about all of them,and have the means to divert those that are on an impact course. Heck, we have a good chance of doing that today, if we see it soon enough.

    So, it will only be about 200 years from the time we first knew asteroids existed until the point they are no longer considered a major threat to our survival. Not too shabby, really.

    I’m more concerned about caldera volcanoes and underwater landslides around volcanic islands like Hawaii and the Canaries. They can and have caused devastation on a hemisphere-wide scale and while it may be possible to avert those natural catastrophes, the engineering it will take is of a far greater scale than required to avert an asteroid collision.

    Let’s hope we have a few hundred years in which to perfect it!

  4. IVAN3MAN

    Dr. Phil Plait:

    This is an important point, We need to find these suckers, we need to understand what to do, and we need to understand how to do it. Think of it this way: we find an asteroid 300 meters across, and calculate it will hit in Germany. Uh oh! So we launch a rocket, use our tech, and push it out of the way… kinda. Something goes wrong, and it only gets nudged. We recalculate the path… and find out it will now hit Pakistan. Oops! Their government might be a little ticked over such a thing, so we need to have some sort of process in place to deal with these (fairly realistic) issues.

    Extract from Wikipedia — Asteroid deflection strategies:

    Carl Sagan, in his book Pale Blue Dot, expressed concerns about deflection technology: that any method capable of deflecting impactors away from Earth could also be abused to divert non-threatening bodies toward the planet. Considering the history of genocidal political leaders and the possibility of the bureaucratic obscuring of any such project’s true goals to most of its scientific participants, he judged the Earth at greater risk from a man-made impact than a natural one. Sagan instead suggested that deflection technology should only be developed in an actual emergency situation.

  5. tacitus

    I enjoyed Armageddon for what it was right up to the point when they’re all saying their teary goodbyes before Bruce Willis sacrifices himself as he saves the day. When an asteroid is about to reach the point of no return any second and wipe out the entire Earth, who the heck delays pushing the trigger for five freaking minutes just to engage in a soppy farewell scene with their kid?

    Honestly, it made me want to stand up in the movie theater and yell “get on with it, you idiot”.

  6. T.E.L.

    Beachmaster,

    The cost of a dedicated detection program would be dwarfed by what’s already spent on public health programs. There’s no good reason to expect a deflection technology to cost an arm and a leg either. And since very early detection vastly reduces the demands, and so the cost, of deflection, it makes plenty of sense to spend some shillings on this, a known threat which is within our abilities to do something proactive about.

  7. T.E.L.

    IVAN3MAN,

    Sagan was occasionally afraid of his own shadow.

  8. TheElkMechanic

    Part of the reason the problem doesn’t get more attention is a lack of compelling acronyms. International Panel on Asteroid Threat Mitigation? IPATM doesn’t spell anything, and you can’t even pronounce it as a pseudo-word. Maybe if they’d named themselves the Society for Prevention of Looming Asteroid Threats, they’d have gotten more media attention before now. Or perhaps the Asteroid Neutralization Union of Scientists?

  9. Cheyenne

    Tacitus- The caldera volcano issue is one of those things that 99.9% of the population has never even heard of (and I agree- that is something to be concerned with).

    Yellowstone happens to have the biggest one. If that erupts in the worst possible way it would (supposedly) dump ash 6 feet deep all the way to the East coast.

    I think it’s pretty cool that we are keeping an eye on asteroids though and getting this technology in place. Sooner the better.

  10. DonQ

    This has to be Plan B… Trusting such a mission to the United Nations has all the strategic wisdom of ‘planning’ to bring a knife to a gunfight.

  11. featheredfrog

    DONT YOU KNOW ITS GODS WIL IF HE WANTS TO TAKE OUT A CITY? YOUOR FLAUNTING HIS DEVINE AND THAT CITY IS PRBLY SINFUL. SODOM/GOMORA ETC.

  12. featheredfrog

    sorry, there should have been a </snark> there…

  13. IVAN3MAN

    T.E.L.: “Sagan was occasionally afraid of his own shadow.”

    Can you blame him, when you consider that President Ronald Reagan, in the 1980′s, had his finger on the “big red button”?

  14. Bjørnar Tuftin

    Taking out a city isn’t “large scale”?

  15. SJC

    ‘Honestly, it made me want to stand up in the movie theater and yell “get on with it, you idiot”.’

    Yeah, I imagine that his delaying to the last possible moment, while averting a collision, would have spawned hurricanes as the asteroid fragments skimmed the upper atmosphere. Not so heroic now, are you, Bruce?

  16. tacitus

    DONT YOU KNOW ITS GODS WIL IF HE WANTS TO TAKE OUT A CITY?

    Can you imagine the orgasm Billo the Clown would have if the city under threat from an impending asteroid was San Francisco? On second thoughts, better not to.

  17. T.E.L.

    IVAN3MAN Said:

    “Can you blame him, when you consider that President Ronald Reagan, in the 1980’s, had his finger on the “big red button”?”

    Well, my point is that just because Carl Sagan said it doesn’t mean it’s in our best interest. And whatever the case, it’s already possible for several countries to contemplate single-handedly diverting small asteroids, for good or evil purposes. Since the threat from asteroids hasn’t been diminished by this state of affairs, we may as well figure out how to deflect them for our own safety.

  18. Thomas Siefert

    I could never understand that it came down to one single man to detonate the nuke in Armageddon. The whole human race was at risk, they should all have stayed to make sure that the bomb went off.

  19. John

    “We recalculate the path… and find out it will now hit Pakistan. Oops! ”

    Not oops, more like great shot there. Anymore asteroids for Iran and North Korea, and larger one’s for Russia and China. Or maybe not, as large ones would be a problem for us all.

  20. Mike

    If we’re dependent on the UN, we are totally screwed.

  21. cid kilroy

    ‘(“Armageddon”, which sucked, and “Deep Impact” which was excellent)’

    boo phil. boooooo.

  22. Charles Boyer

    We can gamble that the big one is a few decades in the future, the last large hit was just 100 years ago.

    And the odds of another hit the next day were precisely the same that they are today. Odds do not change because of a given event. Just because I cast a die and roll a six has no bearing on me casting the die again — the chance that I may roll another six are precisely the same.

    Sorry but the money would be better spent on clean water and simple medicines for the millions suffering right now.

    And even less money could be spent on clean water and simple medicines if we were to spend money on the real problem, overpopulation. Pollution, war, you name it, it likely has its roots in overpopulation.

    could never understand that it came down to one single man to detonate the nuke in Armageddon. The whole human race was at risk, they should all have stayed to make sure that the bomb went off.

    Because if you have Liv Tyler waiting to give you a hero’s welcome, you make damn sure the writer gets you back home safely so you can…celebrate.

  23. I thank the asteroid that he has choosen my home-country to fall on in the first place ;)

    Just like in the nice “end_day” videos (they are really well done and a must-watch; in the last part Phil’s good friend Brian Cox appears. I linked to the first part in my name) where the asteroid smacked down on Berlin!

  24. Joe Meils

    This is an odd question, but my wife and I were witness to another meteor just a couple nights after the Canada one. I’ve been keeping tabs on the reports of these via various news searches, and the number of sightings seems to be up… are we currently passing through a belt of debris, or something?

  25. Joe Meils

    I agree with Phil. Deep Impact was far more believable than Armageddon was. Plus, I much preferred the idea that D.I’s theme was you are better off not giving up until the last possible moment. In all, “A” was about special effects, and macho posturing… D.I. was a much more realistic, human story.

  26. IVAN3MAN

    Has anyone noticed how in movies it’s always the “family man” who ends up getting killed?

  27. Tim G

    It seems like every asteroid or comet disaster movie involves the possibility of humanity being wiped out or nearly so. Far more likely would be a threat of not as great as a Chicxulub but still greater than Tunguska.

    I have long thought that an object posing such a threat would have severe geopolitical repercussions if a partial deflection were possible. This would actually make a more intelligent disaster movie!

    Imagine an asteroid capable of wiping out virtually everything within 500 km is detected and will impact Germany in two weeks. If only a partial deflection were possible, perhaps the impact site could be moved to the less densely populated region of Sweden which would be evacuated. But who will compensate the Swedes? Germany? The United Nations?

  28. Daffy

    “Has anyone noticed how in movies it’s always the “family man” who ends up getting killed?”

    Hence the character “Dead Meat” in Hot Shots.

  29. MarkH

    @TheElkMechanic

    I know how we could get funding from the Star Wars and Apple fans in one annagram.
    International Pannel on Asteroid Detection, Mitigation, Avoidance and Education (couldn’t think of anything else to go here:) ).
    I-PADMAE

    Millions I tell ya, millions :o

  30. JoeSmithCA

    I’d like to point out the positives of an asteroid strike:

    1) A good sized Cretaceous-Tertary class asteroid would be great. We could use the data to finally validate that it was or wasn’t big enough to directly cause the extinction of large animals. Nothing like a good field test to finally resolve that question.

    2) Large scale urban renovation. Demolition of buildings is time consuming and costly, not to mention evicting people from unsafe buildings is difficult.

    3) Large scale temporary/permanent population control. We’ve just go too many people on the earth.

    4) Involuntary, free space exploration: Provided you’re incredibly lucky to survive an insurmountable set of lethal events in just the right way you might just get a free trip into outerspace (for however long you last).

    5) Incredible surfing! Who’s ever been able to claim they’ve ridden a several hundred meter high wave.

    6) Global warming supression. Well, depending on the size of the asteroid, the whole earth might get baked down to bed rock, but you know–at least we won’t have to worry about global warming after everything cools off.

    7) No more cheezy Hollywood asteroid movies!

  31. @BA “and “Deep Impact” which was excellent”

    The biggest flaw in Deep Impact is their depiction of the tsunami wave caused by the impact of the smaller piece of the original comet in the Atlantic? ocean. Of course, they did the Hollywood thing – it’s one big gigantic wave and that’s it. In reality it doesn’t work that way. The tsunami wave is multi-frequency and different frequencies travel at different speeds. The low frequency, long wavelength waves travel the fastest and will be the first to reach the coast.

    There will be a gradual build-up of tsunami waves until the peak amplitude wave arrives and then the amplitudes taper off. For a 1-kilometer wide piece of comet with a density of 1.5 gm per cm^3, impacting at a velocity of 30 km/sec at a point in the ocean where the depth is 1,000 meters – the peak amplitude of the tsunami at a distance of 1,000 km from the impact point will be 48.9 meters. Travelling at a speed of 352 km/hour the tsunami reaches the observer in 171 minutes (2 hours 51 minutes). The wavelength of the peak amplitude is 21.9 km with a period of 3.74 minutes.

    That means that both at 167 minutes after impact and 175 minutes after impact waves slightly less high than the peak of 48.9 meters will slam into the coast. Thus, it’s NOT just one wave as portrayed in the movie. Instead, multiple 10-meter plus waves will slam into the coast over the period of several hours. The stuff that doesn’t get destroyed during the first wave will surely be annihilated after dozens of similar sized waves.

    I supposed I understand why Hollywood didn’t do it this way. The need to explain the multiple waves when the audience expected only one big wave would have probably required some dialog from some of the characters. Better to give the audience what they expect.

  32. tacitus

    This is an odd question, but my wife and I were witness to another meteor just a couple nights after the Canada one. I’ve been keeping tabs on the reports of these via various news searches, and the number of sightings seems to be up… are we currently passing through a belt of debris, or something?

    Very unlikely. A belt of debris — like those that cause the annual meteor showers — is strung out along the orbit of the object the debris came from. Earth passes through such debris belts in a matter of hours, not days or weeks. I suppose that it is theoretically possible for the orbit of a belt of debris to overlap Earth’s orbit for longer, if the two orbits are just right, but I suspect more qualified people than I would tell you that it’s highly unlikely to happen.

    The simple fact is that there are a lot of rocks up there in space. I suspect most people would be shocked by the actual tonnage that hit the atmosphere every year. The law of averages means that we will sometimes see more bright meteors than usual. We tend to want to believe such chance events are more than coincidence, but there’s not scientific reason why that should be.

  33. Steve A

    @Ivan

    This is a good point to consider, but unfortunately it is an argument against all space technology. Everything can be slightly twisted to have military applictions. However, in this case it is somehing to consider, so building a framework, like what is being considered at the UN, isn’t such a bad idea. Also, I think a lot of the mitigation schemes require such long times (like sending a massive probe to over time deflect an asteroid by its own gravity) that you may be able to deal with it faster than actually deflecting an asteroid as a weapon. So far anyways.

    BTW, a new experiment was done showing that an asteroid hit may have been able to spur the generation of life on Earth. It’s describe here: http://tinyurl.com/5pbw77

  34. KC

    >I say we save millions now and take the odds that a space danger is in the far future.

    Gee, thanks for gambling with 6 billion lives. Don’t worry – if you’re wrong the whole clean water and medicine thing will be solved!

  35. Just a simple question.
    When an ASTERIOD enters the atmosphere shouldn’t it be called an ASTER and when it impacts, an ASTERITE?

  36. Jeeves

    Had to smile at the name of the place where the Colorado fireball was recorded: The Cloudbait Observatory.

  37. E.P. Grondine

    Before anyone makes any statements about how minimal a threat asteroid and COMET
    impacts ares they better look at the record. Mankind nearly went the way of the dinosaur several times over the last 6 million years, and here in the Americas there were massive losses of life due to impact during the last 13,000 years.

    E.P. Grondine
    Man and Impact in the Americas

  38. T.E.L.

    Asteroid is something my doctor once gave me.

  39. @E.P. Grondine “Mankind nearly went the way of the dinosaur several times over the last 6 million years, and here in the Americas there were massive losses of life due to impact during the last 13,000 years.”

    However, the greatest natural threat to affect Homo sapiens was the Toba supereruption 74,000 years ago. There is some evidence that this event resulted in a population bottleneck as low as 10,000 people which means it came very close to causing the extinction of Homo sapiens. I’m not sure what kind of a population bottleneck happened in the Americas due to asteroid strikes. Do you have any URLs to share with us on that topic?

  40. Corvus

    TheElkMechanic Says:

    “IPATM doesn’t spell anything, and you can’t even pronounce it as a pseudo-word. ”

    Know what I do to little balls of ground beef when I make hamburgers? I PAT ‘EM.

  41. E.P. Grondine

    Hello Tom -

    I suggest you check the calibration of that genetic clock – the bottlenecks were more likely due to impact than to eruption.

    For the extinctions at the start of the Holocene, you can view the NOVA special online. A rough estimate for human mortality in the Americas at that time is around 90-95%, based on the ending of quarry usage.

    E.P. Grondine
    Man and Impact in the Americas

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
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »