"It's the Size of Texas, Sir"
That classic line comes from the movie, "Armageddon", right before the NASA and government honchos decide to send Bruce Willis and his crew into space to divert an asteroid from its certain collision course with the Earth.
Now for the real thing.
Scientists say a giant asteroid the size of three football pitches will make the closest flyby of Earth in recorded history for an object of its size.
It will pass between the Earth and the Moon and will even come closer than the orbit of many telecommunications satellites, although astronomers insisted that there was little chance of a collision with the massive rock.
Anxious Earthlings need not worry too much for another 24 years, however, because asteroid 2004 MN4 is not due to make its closest approach to Earth until about 10pm London time on Friday 13 April 2029.
The latest calculations of the rock's orbit suggest that it will come so close that it will probably be visible to the naked eye from Britain. It will shine in the sky as a dim, fast-moving star - the first asteroid in modern times to be clearly visible from Earth without the aid of a telescope or binoculars.
The asteroid was first discovered in June 2004 and calculations of its orbit made by astronomers last Christmas Eve suggested that there was a one in 60 chance of it colliding with the Earth. However, within a week this was revised down to virtually zero probability of a collision.
If it did collide it would cause an explosion equivalent to about 20 hydrogen bombs being detonated simultaneously, turning vast areas of land into desert or generating a giant tsunami if it landed in the ocean.
I think we should all promise to meet up on Friday the 13th in 2029 for an asteroid-viewing party. Make your reservations now.
Meanwhile, someone call Mr. Willis and tell him to get his space shuttle ready - just in case.
Now for the real thing.
Scientists say a giant asteroid the size of three football pitches will make the closest flyby of Earth in recorded history for an object of its size.
It will pass between the Earth and the Moon and will even come closer than the orbit of many telecommunications satellites, although astronomers insisted that there was little chance of a collision with the massive rock.
Anxious Earthlings need not worry too much for another 24 years, however, because asteroid 2004 MN4 is not due to make its closest approach to Earth until about 10pm London time on Friday 13 April 2029.
The latest calculations of the rock's orbit suggest that it will come so close that it will probably be visible to the naked eye from Britain. It will shine in the sky as a dim, fast-moving star - the first asteroid in modern times to be clearly visible from Earth without the aid of a telescope or binoculars.
The asteroid was first discovered in June 2004 and calculations of its orbit made by astronomers last Christmas Eve suggested that there was a one in 60 chance of it colliding with the Earth. However, within a week this was revised down to virtually zero probability of a collision.
If it did collide it would cause an explosion equivalent to about 20 hydrogen bombs being detonated simultaneously, turning vast areas of land into desert or generating a giant tsunami if it landed in the ocean.
I think we should all promise to meet up on Friday the 13th in 2029 for an asteroid-viewing party. Make your reservations now.
Meanwhile, someone call Mr. Willis and tell him to get his space shuttle ready - just in case.
posted by cvo @ 9:48 AM
4 Comments:
At 10:11 AM,
Unknown said…
I never saw Armageddon. Did I miss a good thing?
At 10:21 AM,
cvo said…
You missed a typical Jerry Bruckheimer production - think The Rock or Con Air or Pearl Harbor - only set in space.
In other words, you didn't miss much, and I'm sure it was filled with scientific fallacies out the yingyang.
Basically, they landed the shuttle on the asteroid and detonated explosives on the asteroid to break it into smaller chunks and divert it away from Earth - thus saving the planet.
It did have a couple of memorable lines in it - including the line mentioned above.
The President of the United States (or one of his staff) is asking the NASA guy (played by Billy Bob Thornton) about how big the asteroid is and Billy Bob says "It's the size of Texas, sir."
At 12:35 PM,
Unknown said…
The size of Texas. Hmm.
If I recall, the estimated size of the object that appears to have wiped out the dinosaurs is about 15 km. That's big enough to wipe out most plants and animals.
A rock the size of Texas would, um, probably be large enough to assume a spherical shape under its own gravity. It might even be able to rip off enough of the earth's crust to form a new moon, if it hit at the right angle.
It also bears mentioning, I think, that the largest asteroid, Ceres, is smaller than Texas. I suppose that the thing in the movie would have to be a comet, then, but it still seems rather implausibly large.
At 6:41 PM,
R said…
It's interesting the kinds of connections that this blog enables. One of the problems I have been strugging with is how to estimate collision probabilities for a group of satellites that are co-orbiting in a close "formation." The way we usually do this for collisions between spacecraft and space debris is to assume that they are in very different orbits, so that during the very brief span during which their orbits intersect, you can model the relative motion by essentially ignoring they are in orbit at all. For formations, this doesn't work because the relative motion is much slower.
In reading this post, it occurred to me that maybe the way the near earth asteroid folks are computing these collision probabilities might be a good approach to use for formations too. Even though an asteroid impact with Earth is definitely not "slow," the dynamics are much more like what we see in near misses in satellite formations. That is, the orbits are almost on top of each other. Anyway, I followed a few links, and downloaded a paper I'm going to try to find the time to read tomorrow.
Thanks Curtis!
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