Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

City-sized asteroid to pass Earth this fall
space.com ^ | posted: 06:30 am ET 03 May 2004 | Robert Roy Britt

Posted on 05/05/2004 2:51:56 PM PDT by ckilmer

City-Sized Asteroid to Pass Earth This Fall
By Robert Roy Britt
Senior Science Writer
posted: 06:30 am ET
03 May 2004

A minor rumor has hatched on the Internet that a large and deadly asteroid will strike Earth this fall. Bulletin board discussions cite a 63 percent chance of impact, while concerned readers have e-mailed SPACE.com wondering if it is true.

Astronomers know of no such impending doom.

The rumors are likely rooted in a real event, however. On Sept. 29, 2004 an asteroid the size of a small city will make the closest known pass of such a very large space rock anytime this century.


   Images

Computer model based on radar data reveals different views of Toutatis. Note the shallow craters, linear ridges and a thin "neck" between two lobes. The neck my have been chipped away by impacts, or perhaps the lobes came together in a gentle collision.
   More Stories

Asteroid Vesta: The 10th Planet?


Asteroid Might Hit Earth in 2880, Unless it is Painted


Fresh Spin on Solar Powered Asteroids


Long-Destroyed Fifth Planet May Have Caused Lunar Cataclysm, Researchers Say


Animation of Asteroid's Close Brush with Earth

While not dangerous for now, asteroid Toutatis is incredibly strange. And scientists are quite familiar with it, having bounced radar off the tumbling stone on previous flybys to generate computer renderings of its weird shape and movement.

Toutatis looks something like a dumbbell hurtling awkwardly through space. It has a crazy rotation that makes normal days impossible. Scientists can't explain the shape or the spin, but they're eager to learn more in September when, during the close pass, even backyard skywatchers will be able to spot the asteroid.

Well known path

The orbit of Toutatis is pinned down with better precision than any other large asteroid known to cross Earth's orbit. Toutatis' 4-year trek around the Sun ranges from just inside the Earth's path out to the main asteroid belt between Mars and Jupiter. The asteroid visits us every four years.

This fall, it will zoom by our planet within a million miles, or about four times the distance to the Moon.

That's close by cosmic standards for an object that could cause global devastation. Toutatis hasn't been so near since the year 1353 and won't be that close again until 2562, NASA scientists have calculated. No other asteroid so large is known to have come so close in the past, though accurate tracking of space rocks is a fairly recent, high-tech skill that still leaves wide margins of error for many objects.

Toutatis is about 2.9 miles long and 1.5 miles wide (4.6 by 2.4 kilometers).

Many smaller space rocks have passed by much closer, well inside the Moon's orbit. Other asteroids in the size range of Toutatis have surely navigated that window, too, but were unseen in eras when the skies were not scanned so fully as today.

And throughout history, several asteroids and comets have hit the planet. In fact, an object the size of Mars hit Earth when it was very young, creating the Moon, scientists believe. But experts say the odds of a major collision in any year are extremely small. Any other near-Earth asteroid as big as Toutatis would almost surely be spotted decades or centuries before any possible impact.

The prediction of any such event would make huge news rather than small rumors.

Not dangerous, just bizarre

Asteroid Toutatis, officially numbered 4179, was discovered by French astronomers in 1989. Researchers can't predict far enough into the future to rule out Toutatis ever slamming into Earth, so it is listed officially as a Potentially Hazardous Asteroid. NASA says it won't hit for at least the next six centuries.

Meanwhile, previous close approaches have allowed intriguing radar examinations of one of the oddest things in space.

"The vast majority of asteroids and all the planets spin about a single axis, like a football thrown in a perfect spiral," explains Scott Hudson of Washington State University. "But Toutatis tumbles like a flubbed pass."

The result is a lack of anything resembling a normal day or night on the giant, pockmarked space rock.

Instead of a fixed north pole, Toutatis' axis of rotation wanders around in two separate cycles of 5.4 and 7.3 Earth-days. Stars seen from any location on the asteroid "would crisscross the sky, never following the same path twice,'' Hudson says.

More study planned

Steven Ostro at NASA's Jet Propulsion Laboratory has, with Hudson, studied Toutatis via radar on previous flybys. Ostro told SPACE.com that the population of near-Earth asteroids -- hundreds bigger than 0.6 miles (1 kilometer) have been found in the past six years or so -- are now known to come in "a zoo of shapes." And there are other asteroids that don't rotate on a single, main axis.

"But Toutatis remains the only non-principal-axis rotator in the solar system whose shape and spin state are well defined," Ostro said. More radar observations this year will try to further refine the spin rate and orbit.

There is more to learn. For starters, scientists also can't yet say if Toutatis has a hard surface or a thick layer of loose dirt similar to the Moon.

"I'd very much like to know whether Toutatis' strange shape and ponderously slow, wobbly rotation are the result of collisional breaking apart or a gentle merger of the asteroid's two lobes, and when the responsible phenomena happened," Ostro said.

Answers to all these big questions might require an as-yet-unplanned visit.

"Because of the radar investigations, our physical characterization of Toutatis is the best we have for any Potentially Hazardous Asteroid," Ostro said. "But a spacecraft rendezvous could tell us a great deal more, and I would love to see this happen."

Looking both ways

On Sept. 29, backyard skywatchers on Earth can find Toutatis, providing they know where to look.

More to Explore

Map Asteroid Toutatis' location
with Starry Night software.


See the tumbling asteroid
Toutatis
in this video.
Credit: NASA/JPL, S. Ostro, S. Hudson et al.

Toutatis won't be visible to the unaided eye. Ordinary binoculars should be sufficient for spotting it if the sky is clear and dark, says Alan Harris, of the Space Science Institute in Boulder, CO.

"However, to actually know what your seeing, a small telescope would be useful," Harris says. That will allow you to detect the slow motion of Toutatis against background stars. The asteroid will appear as a point of light, much like a star. It is too far for surface details to be visible.

It's also interesting to ponder what Earth would look like form Toutatis. Ostro points out a simple relationship between the distance of Toutatis at this close approach and the size of the Moon. Toutatis will be four times farther than the Moon; the Moon is about ¼ the size of Earth.

"If you were on Toutatis and looked at Earth during the close approach, the Earth would look as large as the Full Moon does to us."

This article is part of SPACE.com's weekly Mystery Monday series.


TOPICS: Culture/Society; Extended News; Miscellaneous
KEYWORDS: asteroid; near; space; spacecom
Navigation: use the links below to view more comments.
first previous 1-2021-27 last
To: ckilmer
I blame Bush. The Jooooos too.
We should first get a UN resolution saying there is an
Asteroid. After 6 months of debate whether the Asteroid
is real, we can then debate for another 12 months whether
the Asteroid is dangerous. Meanwhile the UN will try to
bribe the giant rock into not slamming into us.

In other news, France is trying to surrender to the Asteroid, but experts predict the Asteroid won't listen.
Arabs the World over have declared a Jihad against the
asteroid, saying it's a Jooooo conspiracy.

Also, John Kerry is reportedly trying to hail the Asteroid
wearing his tinfoil hat and yellow bananna tricycle suit.
Earlier today however he was reported to be hiding under his desk crying. He later denied the accusations before admitting to them.
21 posted on 05/05/2004 4:24:22 PM PDT by Shaun_MD ("...Inter Arma Enim Silent Leges - In Times of War, The Law Will Fall Silent..." - Cicero)
[ Post Reply | Private Reply | To 2 | View Replies]

To: JohnBovenmyer
We'll have to learn how to move these masses around. Capturing one of the asteroids seems like a fine idea and something robots could do.
22 posted on 05/05/2004 4:25:38 PM PDT by RightWhale (Destroy the dark; restore the light)
[ Post Reply | Private Reply | To 19 | View Replies]

To: ckilmer
Chunk of rock that big could fer sure make for a bad hair day...
23 posted on 05/05/2004 4:26:06 PM PDT by djf
[ Post Reply | Private Reply | To 1 | View Replies]

To: ckilmer
Irrational, interplanetary, SHTF *bump*
24 posted on 05/05/2004 4:29:12 PM PDT by The KG9 Kid (Semper Fi)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Grig
There sure have been a lot of NEA's (Near Earth Asteroids) recently.

The NEAs have been there all of the time but mostly unseen. It wasn't long ago that investigators began devoting full time and adequate instrumentation to discovering and cataloging the potentially hazardous objects, resulting in a spate of new discoveries.

25 posted on 05/05/2004 4:53:41 PM PDT by ngc6656 (There is no greater peace than sitting with your dog on a hillside on a warm spring day.)
[ Post Reply | Private Reply | To 8 | View Replies]

To: ckilmer
...Great post, good on yer. What a ride that would be strapped to that space rock!!!
26 posted on 05/05/2004 5:21:30 PM PDT by gargoyle
[ Post Reply | Private Reply | To 1 | View Replies]

To: gargoyle
What a ride that would be strapped to that space rock!!!

Slim Pickens highly recommends it.
(The only thing I liked about that absurd Leftist propaganda movie was this scene.)
27 posted on 05/05/2004 8:28:04 PM PDT by walford (http://utopia-unmasked.us)
[ Post Reply | Private Reply | To 26 | View Replies]


Navigation: use the links below to view more comments.
first previous 1-2021-27 last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson