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Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
Asteroid 2012 TC4 may be slightly larger than the space rock that hit Earth's atmosphere near Chelyabinsk, Russia, in February 2013. 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. |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
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. |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
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. |
rob smith Send message Joined: 7 Mar 03 Posts: 22202 Credit: 416,307,556 RAC: 380 |
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 Member of Seti PIPPS (Pluto is a Planet Protest Society) Somewhere in the (un)known Universe? |
Michael Watson Send message Joined: 7 Feb 08 Posts: 1384 Credit: 2,098,506 RAC: 5 |
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 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. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
According to NASA 2012 TC4 will pass at 44000 km from Earth. Tullio |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
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 |
Lynn Send message Joined: 20 Nov 00 Posts: 14162 Credit: 79,603,650 RAC: 123 |
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. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
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 |
moomin Send message Joined: 21 Oct 17 Posts: 6204 Credit: 38,420 RAC: 0 |
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 |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
If you read the text, not the caption, it was at10 million km from the Earth. Tullio |
moomin Send message Joined: 21 Oct 17 Posts: 6204 Credit: 38,420 RAC: 0 |
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. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
This again demonstrates the usefulness of Arecibo radar in monitoring Near Earth Objects. Tullio |
moomin Send message Joined: 21 Oct 17 Posts: 6204 Credit: 38,420 RAC: 0 |
This again demonstrates the usefulness of Arecibo radar in monitoring Near Earth Objects. And that NASA need someone that proofread their articles:) |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
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 |
Michael Watson Send message Joined: 7 Feb 08 Posts: 1384 Credit: 2,098,506 RAC: 5 |
That looks like a large crater, rotating into view at the top edge of the image, near the end of the sequence. |
moomin Send message Joined: 21 Oct 17 Posts: 6204 Credit: 38,420 RAC: 0 |
That looks like a large crater, rotating into view at the top edge of the image, near the end of the sequence.Yes. On its surface near the equator there is a large depression with a diameter of several meters, as well as a dark circular formation near one of its poles. The black “Spot†can be a crater or just a hollow. The diameter of the object is 6 km, 1 km more than previously thought. |
Lynn Send message Joined: 20 Nov 00 Posts: 14162 Credit: 79,603,650 RAC: 123 |
A gigantic asteroid which is larger than the world's tallest building, the Burj Khalifa, will hurtle past our planet in around two weeks time. The 2002 AJ129 asteroid has been classed a 'potentially hazardous' by Nasa and will fly past at speeds of 67,000mph (107,826kmh). This makes it nearly 15 times faster than the world's quickest manned aircraft - the hypersonic North American X-15, which travelled at 4,520mph (7,300kmh). It will pass. |
Michael Watson Send message Joined: 7 Feb 08 Posts: 1384 Credit: 2,098,506 RAC: 5 |
As an interesting contrast, a quite small asteroid called 2018 AV 2, about 8 meters in diameter, recently passed within 2.7 times the distance of the Moon. The only really noteworthy thing about it was its velocity. This was remarkably low , 0.10 kilometers per second, or 360 kilometers per hour. That's less than one percent the velocity of next slowest Near Earth Object, as far as I could discover. One assumes that the object's orbit must closely resemble that of the Earth, yet the 2018 part of it's name indicates that it was only discovered earlier this month. |
moomin Send message Joined: 21 Oct 17 Posts: 6204 Credit: 38,420 RAC: 0 |
And a newly discovered asteroid designated 2018 BD flew past Earth at a very close distance of 0.10 LD / 0.00026 AU (~38 895 km / 24 168 miles) at 15:43 UTC on January 18, 2018, some 7 hours after it was discovered. This is the fourth closest approach to our planet since 2017 EA on March 02, 2017, 2017 GM on April 4, 2017, and 2017 UJ2 on October 20, 2017. https://www.cnet.com/news/asteroid-2018-bd-earth-potentially-hazardous-2002-aj129/ 2018 BD is a newly discovered car-size asteroid that passed us on Thursday -- coming near the altitude where many man-made satellites orbit -- and hardly anyone noticed. |
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