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Author Topic: Is there an Earth-bound asteroid larger than the moon?  (Read 4857 times)

Offline kierae0608

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when is the asteroid thats ment to be bigger and closer to us than the moon suppose to be here. ?
« Last Edit: 06/08/2011 10:59:31 by chris »


 

Offline Phractality

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Re: Is there an Earth-bound asteroid larger than the moon?
« Reply #1 on: 06/08/2011 06:51:48 »
There is no such known asteroid. Perhaps you are thinking of 2011 MD, which passed 12,000 kilometers of Earth on on Monday June 27 at about 1:00 PM EDT. That one was about as big as a tour bus.

Asteroid 2005 YU55 will pass at about .85 lunar distance (327,000 km) on November 8, this year. It'll be the largest ever known to pass that close in recorded history. Still, it's only about 400 meters across. The moon is about 2,160,000 meters across. Of course, many much larger asteroids have hit Earth in prehistory, and many times that number have scored near misses. We just haven't been able to see them until recently. 

I personally believe the meteor that I witnessed on March 12, 2005 was bigger than 400 meters. From what I saw, it apparently skipped three times across the 8-foot swells of the Pacific Ocean and kept on going. Based on other eye-witness reports, it had to be over 200 km away from my location at nearest approach, and it was about the same angular size as the moon, which makes it at as big as an aircraft carrier. Official reports downplay the event as if it was nothing special.
« Last Edit: 06/08/2011 18:39:16 by Phractality »
 

Offline Soul Surfer

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Re: Is there an Earth-bound asteroid larger than the moon?
« Reply #2 on: 06/08/2011 09:35:43 »
What you saw was probably a modest sized man made satellite entering the atmosphere they come in at very low angles often break up and show  green cores because of the copper wiring evaporating and ionising.  I have, many years ago, witnessed a similar meteor.  The size cannot be estimated by the size of the fireball because meteors get surrounded by glowing gas and the brightness makes them look much bigger than they really are.  You must remember most meteors are about the size of a grain of sand and something the size of a pea will produce a spectacular fireball.
« Last Edit: 06/08/2011 09:38:54 by Soul Surfer »
 

Offline CliffordK

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Is there an Earth-bound asteroid larger than the moon?
« Reply #3 on: 06/08/2011 12:24:00 »
I think astronomers have detected all objects this side of Pluto that are larger than our moon.  That doesn't mean that there isn't something beyond Pluto that we don't know about.  Comets often are difficult to detect until they are in the middle of our solar system.

However, the chances of an enormous asteroid the size of our moon just appearing out of nowhere and impacting the Earth are very small.

The US has a new "fireball" tracking system that you can look up meteor sightings on.

http://fireballs.ndc.nasa.gov/
 

Offline Phractality

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Is there an Earth-bound asteroid larger than the moon?
« Reply #4 on: 06/08/2011 18:37:09 »
Perhaps I misread your question. "Earth-bound" could mean headed for Earth or locked in Earth's gravity field. There is an asteroid named Cruithne in a wide orbit around Earth's L-4 point. Cruithne is about 5 km across. Its closest approach to Earth is about 30 times farther than the moon, and it is not expected to get significantly closer to Earth in the forseeable furture. In the long term, however, its orbit is unstable because it crosses the orbits of both Venus and Mars.
 

Offline RD

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Is there an Earth-bound asteroid larger than the moon?
« Reply #5 on: 07/08/2011 00:33:22 »
when is the asteroid thats ment to be bigger and closer to us than the moon suppose to be here. ?

Quote
December, 2012.
http://en.wikipedia.org/wiki/Nibiru_collision
« Last Edit: 07/08/2011 00:35:48 by RD »
 

Offline Soul Surfer

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Is there an Earth-bound asteroid larger than the moon?
« Reply #6 on: 09/08/2011 00:07:50 »
The nibiru collision is complete fiction anything that is as big as a planet entering the solar system would be detected by many amateurs and professionals years before it could get anywhere near the earth and the mechanism of publicing new and important things spotted in the sky is so global and immediate that it could not possibly be hushed up.

That does not mean that we are not at risk of an unexpected collision with a much smaller body though.  however it would be unexpected.
 

Offline syhprum

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Is there an Earth-bound asteroid larger than the moon?
« Reply #7 on: 09/08/2011 06:02:17 »
Although a rogue planet sized object approaching the solar system would very soon be detected how about a planet mass black hole (if such a thing could exist) ? .
Its gravitational influence would of course precede it but how obvious would this be and would any other radiation from it be apparent ?.
 

Offline Soul Surfer

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Is there an Earth-bound asteroid larger than the moon?
« Reply #8 on: 09/08/2011 09:53:28 »
There is no process that could create a planet mass black hole around at the moment  remember this black hole would only be around one centimetre across.  It would also be quite cold and emit minimal amounts of radiation and on a cometary orbit moving very fast and completely undetectable.  If one existed and hit the earth it would go straight through like a bullet in about three minutes and release quite a lot of energy but not swallow a significant amount of the earth as it did it
 

Offline yor_on

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Is there an Earth-bound asteroid larger than the moon?
« Reply #9 on: 12/08/2011 21:29:19 »
Ouch Phractality - 327,000 km -

Too close for my taste.
 

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Is there an Earth-bound asteroid larger than the moon?
« Reply #9 on: 12/08/2011 21:29:19 »

 

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