Sun Tzu

Most of you have probably seen one of these simulations / movie scenes. I'm caught between begin fascinated by the work that went into the animations, and some how feeling like maybe we deserve this after seeing the "leave Britney alone video".

__________________
To confine our attention to terrestrial matters would be to limit the human spirit.- Stephen Hawking

SSJTWIZTA

Woah. That first video is amazing. I cant understand a damn thing that she's saying, but still amazing.

__________________
First they came for the Jews and I did not speak out because I was not a Jew.
Then they came for the communists and I did not speak out because I was not a communist.
Then they came for the trade unionists and I did not speak out because I was not a trade unionist
Then they came for me And there was no one left to speak out for me.
-Pastor Martin Niemoller

bobby

wow......do you think I need 2 disaster kits?

xoxoxoo

__________________
"Life goes on,within you,and...with out you !" xoxoxoo

Martian

It's all a very visually impressive bunch of hooey.

Yes, I believe that is the technical term.

I reckon most folk don't realize that collisions with objects are a daily event. Most are small enough that they burn up within the atmosphere. A few actually make it to the surface and fewer still are large enough to cause any impact damage. There's actually a type of rock known as a tektite, which is a piece of solidified debris caused by impact with some form of solar debris.

The first video is the coolest to watch and also the least likely to actually occur. The object depicted in that video was huge; it's hard to put an exact size on it, but I'd have to say it was at least the size of Charon (~1200 km diameter) and possibly as large as Pluto (~2200 km diameter). The odds of anything that big making it that far into the solar system are slim to begin with and even if it did, it's not very probable that it would get here without us seeing it.

The second and third are from feature films. The third is obviously Armageddon and the second is, I believe, Deep Impact. I take my astronomy from neither Bruce Willis nor Morgan Freeman, thanks.

The fourth is all more or less factually correct, but tries very hard to make everything seem very dramatic. Jupiter is regularly struck by large pieces of debris; part of the reason that so little makes it through to the inner solar system is because of Jupiter and the other gas giants. They have very large gravity wells and act as sort of the defensive linebackers of the solar system, blocking all of the most dangerous objects. The objects in the asteroid belt aren't all that dangerous; if one were to consider them a threat, one would also need to include the Trojans objects as well as the theoretical (or real, for that matter) LaGrangian objects sharing an orbit with other planets. If one accepts the hypothetical Oort cloud as fact, the objects there may pose a threat, but it's really the Kuiper belt that we need to worry about the most, for the simple fact that we don't know nearly as much about the objects there. The real threat, however, comes from what are known as Near Earth Objects (NEOs). There are currently thousands of NEOs catalogued, of which roughly seven hundred are known to pose a potential threat to the Earth. Of all of those, the only one that's considered more significant than background objects is the object mentioned, 1950 DA. While 1950 DA is estimated to be large enough to cause a extinction level event, we do have almost nine hundred years to figure out a solution.

It's not impossible that something will slip through, mind. But every day we scan more of the sky and make more observations about existing objects. Thus, with each passing day the probability of us having one of these things leap out at us, so to speak, diminishes further. With the highest-risk object being the better part of a millennia in the future, this isn't something I'm going to be losing a lot of sleep over.

Still, they're cool videos.

__________________
I wake up in the morning more tired than before I slept
I get through cryin' and I'm sadder than before I wept
I get through thinkin' now, and the thoughts have left my head
I get through speakin' and I can't remember, not a word that I said

- Ben Harper, Show Me A Little Shame