PDA

View Full Version : If a meteroite (Do I have the right term?) the size of Texas..

2006-Dec-01, 04:57 AM
I was watching the movie Armageddon, and I was wondering about something they said. In the movie, the asteriod/meteor/thinger, about the size of Texas, crashed through the asteriod belt and caused a major meteor shower on earth, creating all kind of major damage.

What is the possibility, if an meteor of that size did "crash through" the asteriod belt, would it actually hit anything IN the belt, or are the asteriods too far apart? And if it did hit them, would they actually head towards Earth, or would they scatter? I'm thinking they would scatter about...

But I'm no expert on anything. That's why I'm asking. :)

BISMARCK
2006-Dec-01, 05:39 AM
I'm no expert either, but everything I've read about the asteroid belt says that each asteroid of any appreciable size are so far from each other that if you were standing on one of them, you'd need a good telescope to even see the one closest to you.

So, I'd guess that an asteroid the size of Texas, large though it is, most likely wouldn't hit anything other than dust when crossing the asteroid belt.

I suppose.

01101001
2006-Dec-01, 05:40 AM
What is the possibility, if an meteor of that size did "crash through" the asteriod belt, would it actually hit anything IN the belt, or are the asteriods too far apart? And if it did hit them, would they actually head towards Earth, or would they scatter? I'm thinking they would scatter about...

The Asteroid Belt is not as dense as some might imagine. Routinely, spacecraft pass through it without coming anywhere near an asteroid accidentally. If the spacecraft is desired to pass near one, it must be carefully aimed.

Now, Texas-sized is a bit larger than your typical spacecraft, but it still might pass through without contact. The average distance between asteroids is estimated at 1-million km or 3-million miles, or 2-million km -- take your pick -- according to a quick Google search I just did. I don't want to calculate the probability of an actual encounter during a belt passing.

If hit, an asteroid might head any direction, but with only a minor bump, an asteroid would be inclined by inertia to continue in roughly the orbit it had. If it eventually wound up near Earth, it would take a very long time after it was perturbed. With a major collision, an asteroid would probably be inclined not to remain in one piece; the fragments could probably head anywhere, if they didn't just stick to the Texas-sized object.

antoniseb
2006-Dec-01, 11:42 AM
If hit, an asteroid might head any direction, but with only a minor bump, an asteroid would be inclined by inertia to continue in roughly the orbit it had.
If a Texas sized KBO were to hit a main belt asteroid, the asteroid would leave a crater on the inbound KBO. There would be some escaping debris in Earth's direction, but not much.

Argos
2006-Dec-01, 12:13 PM
Nitpicking, a Texas side object (~1000 km) is now called a dwarf planet.

2006-Dec-01, 01:54 PM
When one describes an asteroid a being "Texas-sized", are they talking about a cone with a Texas shaped cross section and apex at the center of the Earth with a base the size of the surface of Texas? If one takes 800 miles as the longest dimension of the surface of Texas, it would be better to describe the asteroid in terms of the volume equivalent to a sphere of 400 miles radius and the density of silicon---or forget the shape and size and specify the mass.

George
2006-Dec-01, 09:33 PM
I assume any reference to Texas-sized objects is a euphemism; you just can't get any bigger that is tangible to the mind. I think that is what I've heard, or was it "it doesn't get any deeper" than in Texas, in lieu of "bigger". :think: [/cornjunktive]

Anyway, compare the volumes. Even if an impact took place in the belt, the volume inside the belt is 200,000,000,000 times more than the volume of the Earth. Although a splintered object might have at least two chances to hit the Earth as it is thrown back from the sun, these chances are still "slim and none". [This assumes a belt thickness of 1 million miles, though I could not find an established value. This number is much greater than Texas so it defys grasping.] There are other issues, of course, but maybe that helps a little.

01101001
2006-Dec-02, 12:01 AM
When one describes an asteroid a being "Texas-sized", are they talking about a cone with a Texas shaped cross section and apex at the center of the Earth with a base the size of the surface of Texas?

I'd never expect that. Too complicated. When that kind of size is mentioned, I usually picture a sphere, with a diameter equal to the rough diameter of Texas -- something that would punch a Texas-sized hole in my ticket.

From SpaceRef.com: Ceres: A Texas-Sized Space Rock (http://www.spaceref.com/news/viewpr.html?pid=7059)

The Texas-sized asteroid Ceres, about 930 kilometers (580 miles) across, was the first asteroid ever detected.

===

Oh, I don't think anyone addressed the title sub-question directly:

[...] meteroite (Do I have the right term?)

A meteorite is a meteor that landed, and is a kind of rock, like so many other -ite rocks and minerals. A meteor is the rock streaking through the atmosphere. A meteoroid is the rock in space that could become a meteor.

2006-Dec-02, 02:06 AM
A meteorite is a meteor that landed, and is a kind of rock, like so many other -ite rocks and minerals. A meteor is the rock streaking through the atmosphere. A meteoroid is the rock in space that could become a meteor.

Thanks for clarifying that!

And thanks for the info, everybody. It helped a lot- I'm no longer wondering.

:cool:

If a Texas sized KBO were to hit a main belt asteroid, the asteroid would leave a crater on the inbound KBO. There would be some escaping debris in Earth's direction, but not much.

Would a KBO actualy drift all the way to the asteriod belt?

Haha, I'm so full of questions..:)

antoniseb
2006-Dec-02, 04:30 AM
Would a KBO actualy drift all the way to the asteriod belt?
No. There are a few places where that film shows some unlikely events. That's one of them.

Delvo
2006-Dec-02, 05:30 AM
The movie didn't specify that it was a KBO; in fact, in contradicted that idea (at least in reference to what people are usually talking about when they say "KBO") by showing a craggy, spikey shape instead of a sphere. The implication of what they were saying was, to me, that it was from outside the solar system, or at least as far out as the Oort Cloud if not farther.

A KBO or Oort Cloud comet wouldn't just drift into the inner solar system, but it could be perturbed into coming here by another passing object. But if it crossed through the asteroid belt and perturbed some asteroids and small debris there, then it and that smaller stuff wouldn't both go toward the Earth; the objects that were already in the belt would have had momentum in a completely different direction from the big intruder's direction of travel, and their new vector would be a combination of that momentum and the big intruder's influence, not just the same as the big intruder's vector alone.

BTW, to whoever asked why use a vague or hard-to-interpret analogy instead of just specifying its mass: in the movie, the scene that the phrase "the size of Texas" comes from has two guys from NASA on the phone with the President, and one of them starts doing what you suggest, then the other says "It's the size of Texas, sir." So the purpose of the phrase isn't to quantify it with any precision but to convey a quickly-grasped impression to a layman.