Astronomers had some good news for us this week. An asteroid called Apophis passed by in its orbit about fourteen million kilometers away from us. But if the name sounds familiar (beyond references in the Stargate TV series) it’s because in 2004 there were alarming predictions that Apophis could strike the Earth. It didn’t then, but scientists calculated that it would come close in 2029, and had a 1 in 250,000 chance of impacting our planet in 2036. Now, Apophis isn’t huge but it’s moving at tremendous speed, so it would cause a lot of local damage if it were to hit us (though not planet-wide extinctions).
This week’s pass gave astronomers a much better look at Apophis. The bad news is that it’s actually bigger than they’d earlier thought—about 325 meters in diameter. But the good news is that the chance of it hitting Earth in 3036 has been downgraded to 1 in more than 7 million.
You might be breathing a sigh of relief (or you might say, “Hey, I still buy lottery tickets.”)
In any case, if you really want an excuse to cry that the sky is falling, there is one asteroid that will actually pass by the Earth closer than the orbit of some satellites this coming February 15th. It’s called 2012DA14 and it’s about 45 meters across—say, a large building lot.
Checking your home insurance policy fine print for asteroids?
People are already saying we need to wake up and prepare defenses against this kind of hazard, and there are projects in the brainstorming stages, but it will be years before any of them are ready.
For now, we call these objects “near-Earth asteroids”. Maybe one day we’ll call them “target practice”.