published Saturday, November 5th, 2011

Quarter-mile-wide asteroid coming close to Earth


AP Aerospace Writer

CAPE CANAVERAL, Fla. — An asteroid bigger than an aircraft carrier will dart between the Earth and moon on Tuesday — the closest encounter by such a huge rock in 35 years.

But scientists say not to worry. It won’t hit.

“We’re extremely confident, 100 percent confident, that this is not a threat,” said the manager of NASA’s Near Earth Object Program, Don Yeomans. “But it is an opportunity.”

The asteroid named 2005 YU55 is being watched by ground antennas as it approaches from the direction of the sun. The last time it came within so-called shouting distance was 200 years ago.

Closest approach will occur at 6:28 p.m. EDT Tuesday when the asteroid passes within 202,000 miles of Earth. That’s closer than the roughly 240,000 miles between the Earth and the moon.

The moon will be just under 150,000 miles from the asteroid at the time of closest approach.

Both the Earth and moon are safe — “this time,” said Jay Melosh, professor of Earth and atmospheric sciences at Purdue University.

If 2005 YU55 were to plow into the home planet, it would blast out a crater four miles across and 1,700 feet deep, according to Melosh’s calculations. Think a magnitude-7 earthquake and 70-foot-high tsunami waves.

Scientists have been tracking the slowly spinning, spherical, dark-colored object since its discovery in 2005, and are positive it won’t do any damage.

“We know the orbit of this object very well,” Yeomans said.

The asteroid stretches a quarter-mile across. Smaller objects come close all the time, Yeomans noted, but nothing this big will have ventured so close since 1976. And nothing this large will again until 2028.

Radar observations from California and Puerto Rico will help scientists ascertain whether the asteroid is pockmarked with craters and holds any water-bearing minerals or even frozen water.

Amateur astronomers would need a 6-inch-or-bigger telescope and know exactly where to look to spot it.

Astronomers consider 2005 YU55 a C-type asteroid — one containing carbon-based materials. “It’s not just a whirling rock like most of them,” Yeomans said.

Such objects are believed to have brought carbon-based materials and water to the early Earth, planting the seeds for life. The discovery of water-bearing minerals or ice would support that theory, Yeomans said.

This is the type of asteroid that NASA would want to aim for, with astronauts, Yeomans said, especially if frozen water is found. Such asteroids could serve as watering holes and fueling stations for future explorers, he said.

An asteroid is actually on NASA’s short list for destinations.

President Barack Obama wants astronauts headed to an asteroid and then Mars in the coming decades. That’s why the 30-year space shuttle program ceased this summer — so NASA could have enough money to get cracking on these new destinations.

As for an actual strike by an asteroid this size, that’s estimated to occur once every 100,000 years or so.

An asteroid named Apophis — estimated to be 885 feet across — will venture extremely close on April 13, 2029 — but will not strike. It has a remote chance of hitting Earth when it comes around again on April 13, 2036.

Scientists said information gleaned from 2005 YU55, as well as other asteroids, will prove useful if and when it becomes necessary to deflect an incoming Armageddon-style rock.




Purdue University:

about Associated Press...

The Associated Press

Comments do not represent the opinions of the Chattanooga Times Free Press, nor does it review every comment. Profanities, slurs and libelous remarks are prohibited. For more information you can view our Terms & Conditions and/or Ethics policy.
rolando said...

Anyone see the recent movie, Melancholia? It depicts what happens when a moon-sized near-miss passes close-by. Problem is, Earth's gravity did nasty things to its orbit...

These are the same "scientists" who said Man causes global warming...and falsified the data to prove it.

It was calculated decades ago that a solar system object one-kilometer in diameter [that's 6/10ths of a mile, slightly larger than this one] impacting the ocean [more than likely where this one would hit since Earth is mostly ocean] would penetrate the crust causing massive loss of life, etc. This is what happened to the dinosaurs. Seventy-foot tsunami? Yeah, right.

Hopefully it will miss would solve the electioneering issue, though.

November 5, 2011 at 5:02 p.m.
biofish said...

Wait, the scientists are wrong, however your data comes from a movie?

November 5, 2011 at 7:51 p.m.
rolando said...

No, biofish, the movie is new and obviously fiction; the data is from a mid-60s study. Please don't ask for cites...that was 50 years ago. But here is something a bit more modern... . Scary stuff.

[By the way, YU55 is only 1/4 the diameter of the study subject, not 1/2.]

For argument, the study assumed an approach from straight "in front" of the Earth -- opposite Earth's orbital direction -- the worst case scenario; the 1-km asteriod was assigned an estimated, typical terminal approach speed and impacted the ocean in a roughly vertical direction. [These were chosen as nominal characteristics of such a strike.] The water impact was the most disastrous, if memory serves -- the study used both water and earth impact. The estimated diameter at impact was about 500-600m, as I recall, perhaps a bit more -- a conservative estimate. Relative velocity was essentially unchanged when it penetrated the crust.

Who knows, maybe we will experience it first hand...or, perhaps, our intrepid reporter could get this crop of scientists started on another "What if it does hit us?"

"Deflecting" a 1k rock [.6 mi] running at speed? Good luck with that. Maybe Russia or China could launch something, 'cause we sure can't...our technology is gone, to say nothing of the people who built/flew it.

November 5, 2011 at 9:12 p.m.
dude_abides said...

Don't have to deflect it (Apophis). Just affect it gravitationally over a long enough period. This technology already exists. Problem is, dickheads will deny the need just like they still deny global warming, until that option has passed. If it hits the keyhole in 2029, it will be much harder to affect. Thank God The President of The United States of America is on top of the situation.

November 6, 2011 at 12:02 a.m.
prairiedog said...

Global warming is real. The controversy is over whether 100 parts per MILLION of CO2 is the reason. How is 1/10,000th of the atmosphere responsible for a less than 1% change in global temperatures? It's not. Water vapor is the #1 greenhouse gas, and it comes from evaporation over the sea because THE FREAKIN' SUN IS WARMER due to its natural 11 and 22-year cycles.

It was not too many years ago that scientists were warning us of an impending ice age. That's because the sun was cooler; also part of the natural cycle.

There are many viable theories regarding natural phenomena which could result in the warming trend we're seeing, and all of them together are responsible for the single degree of warming that has actually occurred. When they all act together in one direction or the other, they result in either warming or cooling. Most of the time, they are counteracting each other, and nobody notices the difference.

Before you buy into the CO2 theory, at least go take enough math and physics so you can get into a course on thermodynamics, and then figure out for yourself that replacing 100 bricks in a pile of 1,000,000 with 100 other bricks that hold heat a little better will result in raising the total temperature of all 1,000,000 by a single degree. I dare you.

Try this one. How much heat do 7,000,000,000 human beings with an average weight of (minimizing) 100 pounds operating at 98.6 degrees generate? Add to that the heat they use every day for cooking, transportation, etc. Maybe the CO2 is just a side effect of an increased population, and it's really the extra heat generated by a doubling of Earth's population that's to blame.

If public education in this country was any good, most of us would be able to figure these things out for ourselves instead of trusting people who get funding from politicians.

As for the asteroid, it's like a bullet. You never hear the one that gets you. If NASA knew we were going to be hit, they wouldn't tell anybody because there'd be nothing anyone could do.

NASA and its partners (mostly universities) are top-notch when it comes to determining the orbits of objects in space. Either way, it's not something to worry about. Personally, I'd rather die in a really cool cosmic event, just so I could say I was there when it happened. It's got to beat the alternatives I've witnessed over the past couple of years.

November 6, 2011 at 8:02 a.m.
rolando said...

Two points you conveniently omitted, dude.

One, I used "deflect" since that is the word used by the reporter. In any case, The Obama has effectively killed our space research it will remain up to Russia or China to take the necessary action. There's an interesting note on that last: Russia is doing a 500-day+ "reality" Mars-trip scenario. [We are too busy turning communistic to do it.]

Two, I never denied global warming was happening. I and many others including those oiginal "scientists" are denying climate change either way is caused by Man. Man is merely a mote in Nature's eye. And she will out.

November 6, 2011 at 9:31 a.m.
rolando said...

I'd rather die in a really cool cosmic event, just so I could say I was there when it happened.

Good one, prariedog. No one gets out of this alive so might as well be cool about it.

November 6, 2011 at 9:37 a.m.
dude_abides said...

lol. prairiedog, there'd be nobody to tell it to, except the good Lord, and he would probably already know. Your whole life is a really cool cosmic event, and you should hope it lasts as long as possible, unless we get so choked from pollution as to make it unbearable. I want to Occupy this planet forever!
rolandonother1, are you saying the ruskies are gonna "deflect" it from Mars? You say we're trying to be communistic... but it's the communists you hail as our potential saviors! prairiedog, how many ppm of logic in that argument?

November 6, 2011 at 4:25 p.m.
please login to post a comment

Other National Articles

videos »         

photos »         

e-edition »


Find a Business

400 East 11th St., Chattanooga, TN 37403
General Information (423) 756-6900
Copyright, Permissions, Terms & Conditions, Privacy Policy, Ethics policy - Copyright ©2014, Chattanooga Publishing Company, Inc. All rights reserved.
This document may not be reprinted without the express written permission of Chattanooga Publishing Company, Inc.