Skip to comments.Small Asteroid Passes Between Satellites and Earth
Posted on 12/23/2004 6:32:27 AM PST by ckilmer
Small Asteroid Passes Between Satellites and Earth By Robert Roy Britt Senior Science Writer posted: 22 December 2004 10:24 am ET
Astronomers spotted an asteroid this week after it had flown past Earth on a course that took it so close to the planet it was below the orbits of some satellites.
The space rock was relatively small, however, and would not have posed any danger had it plunged into the atmosphere.
The object, named 2004 YD5, was about 16 feet (5 meters) wide, though that's a rough estimate based on its distance and assumed reflectivity. Had it entered the atmosphere, it would have exploded high up, experts figure.
The asteroid passed just under the orbits of geostationary satellites, which at 22,300 miles (36,000 kilometers) altitude are the highest manmade objects circling Earth. Most other satellites, along with the International Space Station, circle the planet at just a few hundred miles up.
2004 YD5 is the second closest pass of an asteroid ever observed by telescope, according to the Asteroid/Comet Connection, a web site that monitors space rock discoveries. The closest involved a rock that flew by last March and was not announced until August.
2004 YD5 was discovered Tuesday, Dec. 21 by Stan Pope, who volunteers his time to examine images provided by the FMO (Fast Moving Object) project, an online program run by the University of Arizona's Spacewatch Project. After the initial detection, other observers noted the object's position during the day and its path was then calculated back. Closest approach occurred on Dec. 19.
The rock approached Earth from near the Sun and so would have been nearly impossible to detect prior to close passage. It soared over Antarctica -- underneath the planet, Washington State University researcher Pasquale Tricarico told the Asteroid/Comet Connection.
Astronomers are aware of this significant blind spot for asteroids that approach Earth while in the glare of the Sun. Only a space telescope could detect such objects before they arrive.
WATCH VIDEO: Prepare for impact! Join the watch for killer comets and ominous asteroids. Spend the night on Kitt Peak with the SPACEWATCH Project stalking the flying mega-mountains that could destroy us ... or save us.
Asteroids orbit the Sun, mostly in a belt between Mars and Jupiter. Some are redirected closer to the Sun, often by gravitational nudges provided by the planets. Earth has been hit by devastatingly large asteroids many times in the distant past. Astronomers say sooner or later the planet will be struck again, but the odds of a large impact occurring in any given century are extremely small.
This has been an interesting year for asteroid encounters.
On March 18, a giant boulder about 100 feet (30 meters) wide passed just above the orbits of geostationary satellites. Its path was bent about 15 degrees by Earth's gravity. The asteroid, 2004 FH, was discovered a mere three days prior.
On Sept. 29, the largest asteroid ever known to pass near Earth, named Toutatis, roamed by at about four times the distance to the Moon. Astronomers had known for years the flyby would occur, since Toutatis is 2.9 miles (4.6 kilometers) long and had been in Earth's vicinity before.
But many near misses by small asteroids likely go unnoticed, astronomers say, because the entire sky is not continuously monitored. Such small asteroids have been detected only in recent years as more sophisticated telescopes have been hooked up with digital cameras.
And some asteroids come even closer, entering the atmosphere. Most never reach the ground because they break apart under the stress of entry. One study of data collected by U.S. military satellites logged 300 in-air asteroid explosions.
2004 YD5 was announced Tuesday evening by the Minor Planet Center in Cambridge, Mass, where comet and asteroid observations from around the globe are digested.
Asteroid? Not a meteorite? Are they just trying the sound dramatic?
That's the tiniest asteroid I've ever heard of. It's the size of a meteorite.
You beat me to it. Sounds like they're trying to be dramatic.
yeah it does sound dramatic.
I think what's got them exercised is how close the thing came and that that they saw late but in real time.
sort of like thousands of years ago when they first started farming and realized their crops depended on the seasons and then began to wonder if spring would return...
It was a spaceship disguised as an Asteroid.
No, asteroid is the correct term. It would remain correct if it were the size of a grain of sand, though it'd admittedly sound a little silly.
Oh, and because I'm an engineer:
Meteoroid: a rock in space
Meteor: A space rock entering the atmosphere
Meteorite: A space rock that has hit the ground.
If I remember correctly, the AP Handbook advises using "asteroid" for all space rocks that don't enter the atmosphere in order to avoid confusion. Most American journalists follow AP style.
Nope. Did not hit the Earth.
Meteoroid? Yes, 'cause is flew by.
Often the smaller asteroids are called meteoroids and the larger ones are called planetoids. Note: Even though a planetoid can approach the size of a moon, since it is in solar orbit, it cannot be classified as a moon.
Meteorites are asteroids that reach the ground. There is no size limit that differentiates one from the other.
Heh, heh, hehh, heh
And if it hits water is it a Meteorine?
Meteoriod is probably the most accurate term. (Same source defines "asteroid" as being between several kilometers and several hundred kilometers in diameter.) It's like the distinction between "ship" and "boat".
meteoroid (mê´tê-e-roid´) noun
A solid body, moving in space, that is smaller than an asteroid and at least as large as a speck of dust.
The American Heritage® Dictionary of the English Language, Third Edition copyright © 1992 by Houghton Mifflin Company. Electronic version licensed from INSO Corporation; further reproduction and distribution restricted in accordance with the Copyright Law of the United States. All rights reserved.
How big does a sail boat have to be before it becomes a ship?
A friend of mine is buying a 118' sail boat.
He didn't know the answer.
At 118' it might be a sailing ship. If it was 118", then sailboat would be fine.
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