Over the break, I couldn’t help being fascinated by the prospect of an asteroid smacking into Mars. At a 1-in-75 chance, the possible January impact of 2007 WD5 into Mars. Then, the news reported that the chances were tripled! That sounds like a lot, but it just means that WD5 now has a 1-in-28 chance of impact. Doesn’t sound too rosy. However, there’s still time for more observations to be made, and a better estimate to be derived. Or, we could just wait until the 30th of January to find out what happened!
You know what, I hope it hits. Yes, if I had the power to intervene and violate mechanistic causality in the favor of striking the planet Mars with 2007 WD5, I would. By putting it that way, that means I’d be using magic. Why the destructive bent, is this some post-modernist artsy desire? No, it’s science!
- We have studied many craters – they’re everywhere in space. However, catching the formation of a crater in real-time would help us refine our understanding of the process, and help predict the outcome of collisions both real and fantastic.
- It would expose fresh terrain on Mars. Given that one of the rovers are near where it might impact, perhaps we might be able to get a ground camera there in a year or so? Well, maybe that would require another violation of causality if the rover is too far from the impact site. But think of what we might learn about the planet from newly exposed layers of rock? Would we find water gushing forth to later freeze and sublimate, or layers of sediment that hint at an interesting geologic and hydrologic past?
- Such an impact would wake people up on this planet to the possibility of asteroids hitting the Earth. There was much public discussion when a comet hit Jupiter years ago, and this would bring the topic back into the public realm. Although few asteroids are currently known to be heading toward the Earth, and the asteroid that could catastrophically hit us in 2014 has only a 1-in 990,000 chance of doing so, we still don’t know the full extent of the risk, and we do not have a way of stopping it.
The time frame of this event is realistic. The asteroid was discovered on November 20th and may hit on January 30. If there’s an asteroid heading toward the Earth, we may have only the couple of months to prepare or respond to it. What would we do if 2007 WD5 was headed toward us with a 1-in-28 chance of impact? Bruce Willis can’t save us this time, just like he couldn’t save the movie Armageddon from being a crappy film. (Yet successful at the box-office!)
What do you think, do you hope, as I do, that on January 30, there’s ejecta blasted into the thin atmosphere of the Red Planet?
There’s another really cool (in a nerdy way) thing about this news. With imprecise measurements you can get a wide range of possible outcomes – and this animation of the probability of impact (from wikipedia) demonstrates it. The range of positions (white line with dots at the ends) that the asteroid may take represents the error rate of the individual observations. As you make more observations, even though they may still deviate from the true position of the asteroid, your mean value will get closer to the true position of the asteroid.
The 1-in-28 chance is based on the fuzzy data, and it could resolve into a 1-in-1 chance of missing, or 1-in-1 chance of hitting dead-on. It makes me wonder, then don’t we need more accurate instruments for tracking asteroids? The “chance” of hitting Mars isn’t so much a random chance like rolling a die, but is more a reflection of the inaccuracy of our measurements.
For more news, go to the Near Earth Object site at NASA.