2006-10-21 12:36:03 · 12 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
I assume you mean all human life, rather than just one poor sap mowed down by a rock the size of a bowling ball.
The short answer is: Not very. Five to six kilometers in diameter will just about do it.
For comparison, take a look at the damage that the Shoemaker-Levy 9 comet did to Jupiter -- even after the comet broke up into a score of little pieces. Each of those pieces created a huge fireball, some of them as big as our whole planet.
The reason for this is that the objects are travelling FAST. (Compare: A bullet is very little threat to you unless it is going fast.) When they hit, they release a tremendous amount of heat and kinetic energy.
EDIT: Ignore the answers that talk about asteroids the size of Texas (or a country). Those folks are watching too many movies. (Michael Bay made the Armaggedon asteroid bigger than the script called for because he didn't think anyone would believe that such a small rock could do so much damage. Now everyone is even more clueless about space rocks than they were before. Sigh.) Oh, and ignore anyone who calls the object a meteor -- a "meteor" is just the light trail in the sky, and those usually come from small particles hitting the atmosphere. A big mountain from space is an asteroid or a comet (depending on its composition).
2006-10-21 12:39:32 · answer #1 · answered by Graythebruce 3 · 1⤊ 0⤋
If you mean *any* human life, I read that a lady a long time ago got a bad bruise on her leg from one that fell through her roof. I was maybe 10-20 lbs or so. It could have killed her if it hit her head.
If you mean *all* human life.The meteor that killed the dinosaurs was roughly 5 miles in diameter. I have not heard anyone make a particularly strong case that such a meteor would *not* cause total human extinction (sorry for all the negatives). Given sufficient planning, though, a small number could survive at least a while.
The Permian extinctor caused much more damage. It was about 30-50 miles in diameter. I think that would do it. Oxygen levels may have dropped enough to suffocate large mammals, if they had been around at the time. It was bad.
2006-10-21 21:30:41 · answer #2 · answered by Dr. R 7 · 0⤊ 0⤋
Large ones are quite rare and I don't think people often find many that are more then a handful. Most finds are rather small, and most don't even make it to the ground. Most Meteors are the size of a grain of sand and burn up in the atmosphere.
I don't think meteors are anything to worry about unless you got a rare large one that managed to go through your car or roof. Asteroids on the other hand are what could be destructive. But they are rare. The next closest NEO (Near Earth Object), and probably the closest in our history, will come past in 2029.
NASA has an interesting "Near-Earth Object Program" section to their site. http://neo.jpl.nasa.gov/index.html
(About the 2029 NEO) http://science.nasa.gov/headlines/y2005/13may_2004mn4.htm
2006-10-22 23:27:51 · answer #3 · answered by Indigo 7 · 0⤊ 0⤋
that depends, one human life or all human life? =)
to be a threat to one person, it could be very small (maybe the size of a basketball?) and that person would have to be rather un-lucky!
To be a threat to us all, well, first of all once a piece of space debris is bigger than about 100 meters (330 feet) it is called an asteroid, not a meteor, and you would need an asteroid about 16 kilometers (10 miles) wide.
2006-10-21 19:49:03 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Actually it would be an asteroid as small as 1 mile across and since they travel at 40,000 mi
an hour it would be an enormous impact and would take out about 1000 sq mi instantly then dust would go into the atmosphere blocking out the sun's rays resulting in a nuclear winter killing off vegitation and eventually us
2006-10-21 22:57:38 · answer #5 · answered by Anonymous · 1⤊ 0⤋
The meteor from the movie andromada ( It was the size of a country!) But any kind of meteor is a threat.
2006-10-21 19:39:50 · answer #6 · answered by omydorego 2 · 0⤊ 1⤋
Supposedly a meteor the size of a basketball on impact will destroy an entire city.
2006-10-22 00:07:43 · answer #7 · answered by Anonymous · 0⤊ 1⤋
One just landed yesterday in the Midwest US that was about 55mm in diameter. It came at such high speed that it became incandescent and set some guy's house on fire and burnt it to the ground. That sounds small but deadly as far as I am concerned.
2006-10-21 19:38:55 · answer #8 · answered by Rich Z 7 · 1⤊ 0⤋
1 mile wide would be enough destruction to repeat the good ol' dinosaur issue
2006-10-21 19:37:41 · answer #9 · answered by Anonymous · 1⤊ 0⤋
Doesn't have to be very large at all if your the unlucky bastard to get hit with it.
2006-10-21 19:46:06 · answer #10 · answered by Anonymous · 0⤊ 0⤋