Closest known asteroid miss on February 15

[mooncliff]

We often detect possible impactors only a few days out.

It is actually worse than it seems. It is not actually necessary that the object have a trajectory directly intersecting Earth. If the speed is low enough and it comes close enough, the object can become gravitationally captured in a chaotic orbit and eventually hit.

See the animation.

http://blogs.discovermagazine.com/ba.../#.UQ56-6VQacM

[c1ue]

Re: Closest known asteroid miss on February 15

Seriously, why is this such a big deal?

http://curious.astro.cornell.edu/que...php?number=470

A study done in 1996 (looking at the number of meteorites found in deserts over time) calculated that for objects in the 10 gram to 1 kilogram size range, 2900-7300 kilograms per year hit Earth. However, unlike the number above this does not include the small dust particles. They also estimate between 36 and 166 meteorites larger than 10 grams fall to Earth per million square kilometers per year. Over the whole surface area of Earth, that translates to 18,000 to 84,000 meteorites bigger than 10 grams per year.

Every shooting star you see is a meteor that 'struck the Earth'.

The ones that matter - the dinosaur killer/Chichon type - or even the Tunguska type, are extremely rare.

[mooncliff]

Re: Closest known asteroid miss on February 15

Because you dont know when the one that will be a big deal will come.
Shooting stars do not strike the Earth. They burn up before reaching the ground.

Tunguska happens much more frequently than what killed the dinosaurs. Read up about it.

[c1ue]

Re: Closest known asteroid miss on February 15

Because you dont know when the one that will be a big deal will come.

And so what then? If you cannot do anything about it, and it is both extremely rare and unpredictable, what exactly is the point of talking about 'near misses'?

For that matter, we've only had satellites for 30 years. For all we know, there have been thousands of near misses, or none.

[quote=mooncliff]Shooting stars do not strike the Earth. They burn up before reaching the ground.[quote]

I don't know where you get your information from, but shooting stars absolutely can and do reach the ground. Most don't, but simply because you can see a shooting star doesn't mean it is going to burn up in atmosphere.

Tunguska happens much more frequently than what killed the dinosaurs. Read up about it.

Sure, and how often has a Tunguska happened in a populated area? Oh right, never so far.

Eventually it will happen, but the fact is, the Earth is a very, very large area. Despite 7 billion-ish people, the Earth isn't so full that a Tunguska will automatically strike a populated area. Just consider the hundreds and thousands of tornadoes that crisscross the Central US every year - despite that, deaths and injuries are quite few.

[BadJuju]

Re: Closest known asteroid miss on February 15

I agree with c1ue here. It simply isn't something you should worry about it. It is wildly improbable.

[aaron]

Re: Closest known asteroid miss on February 15

I agree with c1ue here. It simply isn't something you should worry about it. It is wildly improbable.

But it sure does get you research dollars!