Whether or not we acknowledge it, the possibility of an asteroid impact on the Earth continues to loom over us, along with the possibility that humankind may well go the way of the dinosaurs. Asteroid impacts may be rare, but they can have utterly devastating results; moreover, thinking about how to estimate and respond to asteroid impacts good practice for all kinds of thinking about big-picture, slow-changing planetary challenges. We now have another chance to practice.
According to New Scientist, asteroid 2004 VD17 has been given a Torino scale rating of 2 -- higher than any other object in the sky, at present -- indicating a small but measurable risk of impact. As of measurements on February 26, the asteroid has a 1 in 1600 chance of hitting the Earth in 2102 -- an increase over the initial estimate. So far, almost every time astronomers have discovered an asteroid on a potential impact course, subsequent refinements of the data confirm that the rock will miss us. It's extraordinarily rare for further refinement to increase the measured risk; the last time this happened was with asteroid 2004 MN4, which is now estimated to miss the Earth by a whisker in 2029.
It's likely that further observations will put the risk of impact at 0 -- but it's not guaranteed. Eventually, we will find that an asteroid is on a direct impact orbit, and we'll have to start thinking about how to deal with it. That's why this bit from the New Scientist article so frustrating:
NEO [Near Earth Object] hunter, Andrea Milani Comparetti of the University of Pisa, Italy, says VD17 "is a serious problem, but not for our generation".
Dr. Comparetti is absolutely wrong. A major impact in 75 or so years is a problem for our generation, because all of the plans for making certain that we aren't hit require both a great deal of preparation and a long time for execution. The "gravity tugboat" idea, for example, which was proposed last year in the pages of Nature, would require that a 20 ton space craft be parked by an asteroid for a year or more, at least twenty years before the possible impact. Given that VD17 is three times the size of the one used for the gravity tugboat idea, it would need both a bigger space craft and more time. We've never put that much mass into deep planetary space, and would need a decade or more to design, build and test the equipment necessary -- this is not something that we'd have many chances to retry if it failed.
And while a 580 meter asteroid isn't a planet-killer, it would do tremendous damage. Based on the Asteroid Impact Effects page at the University of Arizona, if VD17 was an otherwise typical dense rock asteroid, it would hit the ground with an impact equivalent of a 10 gigaton nuclear bomb, knocking down buildings a hundred or more kilometers away, and leaving a 9 kilometer-wide crater.
This is one of the key reasons why an active robotic space program is so important: a civilization that cannot get its tools into space is a society that cannot save itself from destruction.
The biggest problems our planet faces are, unforunately, the ones that we seem least well-equipped, cognitively, to handle. Evolution has gifted our brains with the ability to analyze a situation quickly, looking for subtle patterns and clues related to past experiences. Problems that unfold slowly, or take a long time to show change (for the better or worse), or have a significant lag between cause and effect, appear to our monkey brains as not-problems. We need to train ourselves to take the long view, to examine the big picture.
It's possible that as we figure out how to deal with climate disaster, we will pick up that training as a matter of course. If we're lucky, we'll do so in time to deal with the next round of big picture problems, asteroid or otherwise.
This sort of information really gives credence to programs like LiftPort (http://liftport.com/) that are trying to make space more accessible. The main limitation to space has always been flight and payload availability for many programs. If LiftPort can deliver on their 12 year deadline to get to orbit (via a space elevator), then we have a major transformational tool at our disposal that can deliver a very advanced detection and deflection package.
Jamais, you make a valid point, but it's going to take a lot of worldchanging for us to start worrying about vague threats of catastrophe in 100 years time, especially as more immediate catastrophes can arise without warning and have to be dealt with. Consider what happened with the reporting of 2004 MN4: the most significant threat since observations started (likelihood of impact getting as high as 1 in 50), yet its publicity was literally swamped by the Boxing day tsunami.
Still, with six billion+ souls aboard, I think we can afford to do a few things in parallel!
Just to underscore your point: while 2004 MN4 will just miss the Earth in 2029, a miss will *not* as good as a mile. The asteroid will pass so close to the Earth that it will be clearly visible to the naked eye as it whizzes past (est mag 3), and it will be deflected into a new orbit. The dynamics of that orbit cannot be determined beforehand, but there is a slight possibility that it will result in a collision in 2036.
(refer New Scientist, Jun 25, 2005: http://www.newscientistspace.com/article/mg18625051.200.html. subscription needed)
Jamais says, "We need to train ourselves to take the long view, to examine the big picture."... So true, but based on recorded history chances the are slim.
Looking on the bright side, good news is if we all die in a fiery ball of asteroid death everyone goes to heaven.
Xavier, just so -- and we've pointed to Liftport's work several times over the last couple of years. Many of us here are ready to buy elevator tickets!
Still, with six billion+ souls aboard, I think we can afford to do a few things in parallel!
I agree 100%!
I've actually posted a few follow-up pieces on 2004 MN4 (aka Apophis), including this one outlining the 2035/2036 chances. For what it's worth, Schweikart and others have argued that dropping a transponder onto MN4 the next time it comes near would allow us to pinpoint its orbit and give us a better shot at predicting whether we need asteroid insurance for the mid-2030s...
Looks like Apophis is Looks like Apophis is no longer predicted to come close in 2029. At least, if I read all that info on the NEO site right.
Still it's always reassuring to know that the project continues.
You know, a near miss might be a right useful thing to happen.
Kinda get folks' attention, you know?
And open up a thriving market in tickets for the Space Ark. (Wow, that would make a wonderful new spin on the Nigerian scam.)
Sorry for doing this Jamais, but there seems to be a problem with the contact email system at WorldChanging. It keeps on asking me to input an email address (which I do) but does not recognize it. I haven't sent two emails to WorldChanging in several months, so i don't think that this could be a problem.
PS - This was the message I wanted to send...
Just thought you should check this site out. At first I thought they were a bunch of cranks, but then I started reading about the contracts they were getting and the validation test that they were undergoing. It looks like this company is just about to produce a polymer based room temperature super-conductor. Might be worthwhile...
People keep mentioning Liftport without any prompting and we're going to think we're onto something.
Someone said it a few years ago, around a conference call .. we're selling hope. That sounds corny in the cold light of day but it feels right. Hard to hang a business plan on that of course.
Jamais, you make a valid point, but it's going to take a lot of worldchanging for us to start worrying about vague threats of catastrophe in 100 years time,
We don't - I submit - need to actually DO a lot of worldchanging to make asteroid defense doable. We only need to put in place infrastructure in space that is flexible and adaptable to changing circumstances.
When incoming is sighted you take a few days, inventory what you've got in cis-lunar space, equip the craft with supplies and off they go. Dramtic tension and movie-of-the-week material but we don't have a forlorn hope and we don't have to just sit around and _watch_ like dinosaurs.
Getting to that point is not easy, I'll allow. But we're so damned close to being able to make it happen. Dropping the price to orbit south of $500 dollars a pound should be the straw that broke the chicken's egg.
Here is an analogy to the Asteroid issue.
Spacecraft typically have what is called a watchdog timer. The watchdog timer counts for a specified period (say, 30 seconds) and then sends a signal to power cycle the main processor board on the spacecraft. The flight software on the main processor board sends a reset signal to the watchdog timer during each specified period to prevent the watchdog timer from sending the signal to power cycle the board.
With this arrangement, if a flight software glitch locks up the main processor, the watchdog timer will power cycle the board because it never received a reset signal.
The asteroid (in the aggregate) is the watchdog timer, and life the software. Every 60 million years or so, the watchdog timer restarts the evolutionary process (power cycles the board). It repeatedly does this until life becomes interesting enough to be able to reach out and reset the watchdog timer, by deflecting/destroying the asteroid. The main difference is that in our situation, the software has to write itself from scratch between restarts. Perhaps the current version of the software will be able to reset the watchdog timer in time.
By the way, the current version of the software also has the capability of restarting the board on its own, unfortunately.
Since our technological prowess is already naturally advancing exponentially, it seems quite certain that we'll either have already destroyed ourselves or will easily reject the asteroid by the time it arrives (if it were to). No special preparation necessary. Artificial risks far outclass the severity and likelihood of natural risks as far as destroying the human race in the next century, hands down.
Aside from giving us the means to deal with something coming in well before VD17, starting to prep early also avoids the "oops" experience of the exponential advance of technology not going in a direction that makes shifting asteroids a casual affair.
It may well be that super nanotech and post-singularity AI will make deflecting incoming asteroids a piece of cake -- if so, hurray! But if things don't work out that way, basing all of our plans on a future of indistinguishable-from-magic technology will seem a bit... short-sighted.
I agree. We need to be pushing for this capability now. Simply waiting for technological advancement to give us a better tool kit is risky. They might not be the right tools. We should push (or at least nudge) R&D with the goal (among other goals) of being able to deflect and mine asteroids.
How about a Tunguska Event Centennial Party? It would be a fun way to remind everyone of how lucky we were, and that we might not be so lucky the next time. Mark you calendars for June 30, 2008!