At quarter to five this afternoon, the Earth will almost be hit by an asteroid. Asteroid 2004 XP14 will pass within 450,000km - around 1.1 times the orbit of the Moon. Which is good, because at half a mile across, if it hit us we'd be looking at some serious damage. Probably not the end of civilisation - we're spread out enough that we'd need a much bigger rock to do that - but it would destroy a city, or if it landed in the ocean, cause massive tsunamis which would inflict devastation across a wide area.
Whenever I see a story like this, I can't help thinking the same thing: there are an estimated 2000 near-Earth asteroids big enough to be a problem. And we only know about a couple of hundred of them. Given this paucity of data, we might not know about it until it was far too late.
... 2000 at least, and with a continuing supply from the Kuiper Belt and the Oort Cloud. We're lucky in having the gas giants vacuum up a fair proportion, but plenty will get through - Earth seems to get zapped by a biggie every 70m years or so - we're probably coming up for one soon (just to be alarmist). My bet is one from the Kuiper Belt, which is near enough to the same plane as us.
ReplyDeleteComfort yourself in the maths:
ReplyDeletecross section of the earth = ?r2 = 111 million sq km.
area of a 450,000km circle = 628 billion sq km
Ratio = 1:5000 - so 1 in 5000 asteroids like this will hit us. If interactions like this happen every few years, it's highly unlikely that it'll happen in our lifetime.
The most important question is what will the policy response be from Labour to ensure there is no asteroid attack. Maybe a Kyoto Protocal for asteroids also?
ReplyDeleteThe meteor due in 2011 will be more interesting. It's supposed to hoon past the planet at a distance of 160K kms, about half the distance from the earth to the moon.
ReplyDeleteThe Society for Persecution of Community Sinfulness today launched an attack on NASA for its asteroid missions. In particular, it lambasted the US national space agency for unnatural encounters with the 'long, pendulous and suggestively shaped' asteroid Eros, which strongly resembles a....
ReplyDeleteCraig Y.