Horizon; Asteroids

[Mich the Tester]

Saw this last night, quite enjoyable; watch it here if you've missed it.

BBC - BBC Two Programmes - Horizon, 2010-2011, Asteroids - The Good, the Bad and the Ugly

[TimberWolf]

I had it on in the background but it was so drawn out that I missed the important details about small asteroids being more of a threat. They could have condensed the whole thing into a couple of minutes.

[kandr]

I had it on in the background but it was so drawn out that I missed the important details about small asteroids being more of a threat. They could have condensed the whole thing into a couple of minutes.

I would have thought the bigger the asteroid that hits the earth, the more damage, but then I am basing it on physics of our universe.

[Ravello]

I would have thought the bigger the asteroid that hits the earth, the more damage, but then I am basing it on physics of our universe.

I didn't watch the program, but I'd assume that whilst the above is true, the greater risk from smaller asteroids is due to the fact that there are many more small asteroids floating about the place than there are those of earth-destroying proportions...

[Mich the Tester]

I had it on in the background but it was so drawn out that I missed the important details about small asteroids being more of a threat. They could have condensed the whole thing into a couple of minutes.

The big asteroids seem to have been identified, and the chappies who track them are confident that none are going to hit earth any time soon. But there was an interesting bit about a small asteroid that exploded over Sudan in 2008; it was spotted only 20 hours before it hit earth. Trouble with small asteroids is that you can´t see them coming, but when they hit they can cause immense damage as they explode above the ground; the shockwave from the explosion hits the ground and sends extremely powerful winds in all directions, so strong they can pick up a house and dump it hundreds of kilometers further up. The two well known hits by small asteroids are Tunguska in Siberia in 1908, and Sudan in 2008; both happened in very sparsely populated areas, luckily.

[TimberWolf]

If you want to learn something interesting about orbital mechanics, try Googling "orbital resonance". Not only interesting for planetary formation reasons, but in the creation of integers from a continuum too. Not just integers from nowhere, but special ratios of integers too. Quantum mechanics has a similar thing where quanta arise from a continuum. You just can't avoid those darned integers.

[kandr]

I didn't watch the program, but I'd assume that whilst the above is true, the greater risk from smaller asteroids is due to the fact that there are many more small asteroids floating about the place than there are those of earth-destroying proportions...

But surely the smaller ones burn up in the atmosphere?

[DimPrawn]

I had it on in the background but it was so drawn out that I missed the important details about small asteroids being more of a threat. They could have condensed the whole thing into a couple of minutes.

Usual dumbed down BBC Horizon.

Asteroids are rocks, some are big, some are small, the big ones are easier to spot, so the small ones are more dangerous as we won't have much/any warning that one is about to hit a major city.

There you are, why do they need an hour to tell you that.

[DimPrawn]

But surely the smaller ones burn up in the atmosphere?

By small they meen a few hundred meters across, rather than several km.

They have a tendency to explode in the atmosphere.

Tunguska event - Wikipedia, the free encyclopedia

[Mich the Tester]

Usual dumbed down BBC Horizon.

Well at least it was more interesting than yet more politics, eco-bloody-nomics or financial markets and that kind of boring crap.

Just thought I'd get a slightly nerdier thread going to amuse the science geeks among us.

Sorry,