Southwest Research Institute Clark R. ChapmanYou asked us great meteor questions, readers, ones that went beyond the mere fact of the seriously cool video coming from all over Russia. But we wanted to give you a deeper look at the science behind bombardments from space, so we called in a respected source to help.
Clark R. Chapman is a senior scientist at the Southwest Research Institute in San Antonio and a pioneer in the field of asteroid threat assessment. He is co-author of the 1989 book, “Cosmic Catastrophes†with David Morrison, a senior scientist at the NASA Ames Research Center in Mountain View, Calif.
This is an unusual strike. It will take a while for analysis of the videos, and presumably of the seismic records of the explosion, before we can estimate the size of the projectile. I’m guessing it’s a once-in-a-decade kind of event.
Why unusual
It’s unusual in the sense that it’s rare. It’s not the kind of event that happens very often. A! lso, they’re talking about maybe 1,000 people injured and some in the hospital. I’m not aware of a strike that has caused that much injury. That’s because it hit in a somewhat populated part of Russia, instead of the ocean or the desert or the middle of Siberia where relatively few people would have got hurt.
These things happen continually. This one was probably a few meters in diameter but they’re flying by the Earth ll the time. And they hit - ones this big - maybe once in a decade. Things that would really devastate a city if they hit would occur maybe once every few centuries. It happens on a scale (of meteors small and large). Anyone living out in the countryside or a rural area, if the skies are clear, can look up at night and see apple-seed-size meteors hitting every few minutes, or at least every few hours.
Conceivably it could be part of a swarm, but it’s not associated with DA14 [the big asteroid that is to fly close by the Earth on Friday]. They’re on totally different trajectories. I ! don’t h! ave the numbers in front of me, but their orbits are totally different. They both intersect the Earth, more or less, but the asteroid is moving maybe south to north and the Russian meteorite west to east. They’d have to be coming in the same direction to be part of a swarm. It’s a remarkable coincidence that what may be the most damaging meteor strike in modern history would happen on the same day as the closest passage of an asteroid as big as DA14.
How big is DA14
It’s about 100 feet across.
Should we be scared What can we do
The estimated danger from a large impact has dropped in recent decades because of telescopic observations and sky surveys. We should continue to monitor the skies for undiscovered large asteroids and for very much smaller ones that could still be quite dangerous, depending on where they hit. We should continue to look.
No space telescope now searches for such threats. Would such a device help
That kind of project wouldn’t find what hit Russia (as the asteroid was too small) but it would find ones that are much more dangerous. And once they were detected, we could warn people. We could say, “It’s going to hit such an area at a certain time on a certain day and you should stay away from the windows.†You could provide warning of impacts that could be dangerous.
Could we divert a planetary threat
If it’s found early enough - quite a few years in advance of its hitting - then NASA and the European Space Agency and other space agencies have the technology to divert the asteroid so it would miss the Earth.
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