Like you, I thought asteroid impacts were the stuff of movies. They were an abstraction I figured, products of an overly imaginative screenwriter…and then I met Ed Beshore. Ed’s a scientist at the Lunar and Planetary Lab in Tucson, Arizona. It’s his job to find those asteroids that might pose a threat to Earth. How many has he found?
“When I started doing this job there were only about 170,000 asteroids known and now there’s over 400,000,” he told me. Four hundred thousand? The crew and I spent the night up at the frigid summit of Sacramento Peak as Ed scanned the skies looking for asteroids. He’s fulfilling a Congressional mandate to locate and catalogue every asteroid a kilometer across or bigger that’s within 30 million miles of our planet. So far they’ve found about a thousand of these huge rocks and luckily none of them appear to be on a collision course with Earth. However, in looking for these Ed and his team find a lot of smaller asteroids that might still pose a problem.
“It can be sobering,” he said. “I do recall the first time I actually started working here it showed me all the asteroids that were flying around and it really brought home the fact that space is full of asteroids.”
Earth in fact sits in the middle of a cosmic shooting gallery. I’m paraphrasing a great book by Phil Plait on everything in the cosmos that can kill us, but it’s true. Everyday this planet is pelted with up to 20 tons of stuff falling in from the supposed vacuum of space. Most of this so-called stuff is small, but sometimes big rocks come roaring in. We’ve all heard of the asteroid that killed the dinosaurs 65 million years ago. It actually may have been a pair of giant space rocks since the discovery of a massive crater in the Indian Ocean from about the same time period. Some of you may have heard about the impact in a remote region of Siberia called Tunguska that happened in 1908. So what’s in store for the future? More impacts…a lot more impacts.
It’s a certainty that Earth will again be on the receiving end of a cosmic reaming. In fact, it’s a threat that we’re only now beginning to take seriously. Back in the 90’s Congress mandated that we find all space rocks a kilometer wide or bigger. They recently asked that we find all that are a 100 meters wide or bigger. The National Academy of Sciences just released a report saying that we in fact do need to find these rocks because it will take years, if not decades to come up with and implement a plan of attack. However, the bad news is there isn’t the money to fund a census of all the big rocks that can hit us and maybe cause widespread destruction.
So that leaves us with Ed and the skeleton crew working to scan the sky for errant asteroids, which is good, but not good enough.
“There aren’t very many people on the planet doing this job and it really is quite sobering to think that you as an individual are one of the people actually looking out for the planet.” Ed told me at the telescope. “We may find one day that there is something dangerous that we do have to respond to, not only as a nation, but as an entire planet and it could be one of the discoveries that we make right here.”