Asteroids & Comets

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Profile janneseti
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Message 1880897 - Posted: 29 Jul 2017, 3:17:30 UTC - in response to Message 1880814.  

Asteroid 2012 TC4 may be slightly larger than the space rock that hit Earth's atmosphere near Chelyabinsk, Russia, in February 2013.
No biggie so to speak.
https://www.jpl.nasa.gov/news/news.php?feature=6906/
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Profile Tom Miller
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Message 1881679 - Posted: 2 Aug 2017, 21:31:01 UTC - in response to Message 1401413.  

There is a lot more space than asteroids. In theory one day, one will hit us, statistically it has to happen. What will be the outcome no-one can say.


Yupper, it has happened. Consider the 67 million year old Dinosaur ending asteroid that hit us in modern day Yucatan.

Tom
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Message 1881860 - Posted: 3 Aug 2017, 15:27:56 UTC - in response to Message 1880897.  

Asteroid 2012 TC4 may be slightly larger than the space rock that hit Earth's atmosphere near Chelyabinsk, Russia, in February 2013.
No biggie so to speak.
https://www.jpl.nasa.gov/news/news.php?feature=6906/

That depends on where it hits.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
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Message 1881862 - Posted: 3 Aug 2017, 15:29:50 UTC

I wonder how many asteroids fall into one of earths vast oceans and if the most common ones that make it to the surface can generate a big wave.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
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Profile Chris S Crowdfunding Project Donor*Special Project $75 donor
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Message 1881892 - Posted: 3 Aug 2017, 18:21:03 UTC - in response to Message 1881862.  

I don't think that any small asteroid would fall into earth's oceans, it would likely get burnt up in the atmosphere on the way down. meteorites do get through and there are quite a few samples to be found on land. If in time a big one hit an ocean that would be bad news all round.

https://whyfiles.org/106asteroid/2.html
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Profile William Rothamel
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Message 1881940 - Posted: 3 Aug 2017, 23:14:28 UTC - in response to Message 1881892.  

There was one overhead in Key West Florida which exploded and hissed by in flames. I saw it as we were about to march in for the sacrament of confirmation. The Navy said it landed in the ocean around Cuba --100 miles away. Size was indeterminate as you had no frame of reference to judge it's height.
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Message 1881997 - Posted: 4 Aug 2017, 7:11:02 UTC

We do have the NEO program now, but if a real biggie headed our way, we'd know it was coming but not be able to do much about it. The most we could do with current technology is fire all out ICBM and nuclear stuff at it hoping to break it into smaller fragments.

The last big one was in the Chicxulub crater in the Yucatan Peninsula 65 million years ago, that wiped out the dinosaurs, and 75% of plant and animal life on earth. It was estimated to be 6-9 miles in diameter, and carved out a crater 110 miles in diameter and believed to be 12 miles deep.
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Message 1882004 - Posted: 4 Aug 2017, 7:51:28 UTC

The trouble is most of the ICBMs are not designed to be launched into space, only to enter low earth parabola - one would want to hit the rock when it was at least four or five times the earth-moon distance away (preferably a few tens would be better).
Bob Smith
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Message 1882049 - Posted: 4 Aug 2017, 13:40:40 UTC - in response to Message 1881997.  

We do have the NEO program now, but if a real biggie headed our way, we'd know it was coming but not be able to do much about it. The most we could do with current technology is fire all out ICBM and nuclear stuff at it hoping to break it into smaller fragments.

The last big one was in the Chicxulub crater in the Yucatan Peninsula 65 million years ago, that wiped out the dinosaurs, and 75% of plant and animal life on earth. It was estimated to be 6-9 miles in diameter, and carved out a crater 110 miles in diameter and believed to be 12 miles deep.


The heavy lift rockets used to send space probes beyond Earth orbit would be needed, with as large nuclear warheads as they could carry, on top. Adapting nuclear warheads to these rockets might prove difficult.

It would probably be better to detonate the warhead a little distance from the asteroid, so as to push it slightly off course, making it miss us. Breaking it up would take up much of the energy, reducing the diversion effect. It would also be unpredictable. If the asteroid could be reduced to pebbles, fine. What if it was more durable, and merely split into a number of large pieces, all headed our way? That could be almost as bad as leaving it alone.
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Message 1883127 - Posted: 11 Aug 2017, 7:22:25 UTC

According to NASA 2012 TC4 will pass at 44000 km from Earth.
Tullio
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Message 1884667 - Posted: 18 Aug 2017, 7:22:11 UTC

Asteroid Florence, named after Florence Nightingale, will pass at 7 million km from Earth on September 1. It is 4.4 km wide and could be a real danger if closer.It will be tracked by radio/radar telescopes at Goldstone and Arecibo.
Tullio
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Message 1897519 - Posted: 26 Oct 2017, 6:22:54 UTC - in response to Message 1884667.  

From Lyra??


We may have just seen the first comet from another solar system


The solar system may be hosting a visitor from the stars. A newly discovered comet is screaming away from Earth, and based on its weird orbital trajectory astronomers think it might be the first comet ever observed that came from interstellar space. A sky-surveying telescope in Hawaii spotted the fast-moving object, now called C/2017 U1, on 18 October, after its closest approach to the sun.

Michael started a thread on this Comet. Posting for posterity.
ET Phone Home
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Message 1908805 - Posted: 24 Dec 2017, 18:11:23 UTC
Last modified: 26 Dec 2017, 3:10:29 UTC

Arecibo is again working as a radar and has monitored Phaeton 3200 on 16 December. What is funny is that the caption of the images says that Phaeton 3200 was at 1.8 million km from the Earth, while the following text says that Phaeton3200 was at 10 million km from the Earth. Anyway, welcome Arecibo!
Tullio
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Message 1909153 - Posted: 27 Dec 2017, 11:33:52 UTC - in response to Message 1908805.  


Observations of Phaethon were conducted at Arecibo from Dec.15 through 19, 2017. At time of closest approach on Dec. 16 at 3 p.m. PST (3 p.m. EST, 11 p.m. UTC) the asteroid was about 1.1 million miles (1.8 million kilometers) away, or about 4.6 times the distance from Earth to the moon. The encounter is the closest the object will come to Earth until 2093.
https://www.nasa.gov/feature/jpl/arecibo-radar-returns-with-asteroid-phaethon-images
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Message 1909156 - Posted: 27 Dec 2017, 12:03:42 UTC - in response to Message 1909153.  

If you read the text, not the caption, it was at10 million km from the Earth.
Tullio
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Message 1909157 - Posted: 27 Dec 2017, 12:42:22 UTC - in response to Message 1909156.  

I didn't notice that:)
And it was about 27 times the distance from Earth to the moon.
Not 4.6 times the distance from Earth to the moon as the caption says.
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Message 1909235 - Posted: 28 Dec 2017, 7:07:30 UTC - in response to Message 1909157.  

This again demonstrates the usefulness of Arecibo radar in monitoring Near Earth Objects.
Tullio
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Message 1909238 - Posted: 28 Dec 2017, 7:40:38 UTC - in response to Message 1909235.  

This again demonstrates the usefulness of Arecibo radar in monitoring Near Earth Objects.
Tullio

And that NASA need someone that proofread their articles:)
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Message 1909268 - Posted: 28 Dec 2017, 14:51:54 UTC

Proofreading has been abolished by most publishing houses.New books and articles are printed from magnetic medias, with all errors included. This is called progress.
Tullio
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Message 1909280 - Posted: 28 Dec 2017, 16:03:12 UTC

That looks like a large crater, rotating into view at the top edge of the image, near the end of the sequence.
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Message boards : Science (non-SETI) : Asteroids & Comets


 
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