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Posted on 11/13/2007 9:52:30 AM PST by SunkenCiv
I will start by commending the Committee for its efforts since the early 1990s in seeing that this public safety issue is responsibly addressed. The impact of near-Earth objects with the Earth is properly described as a cosmic natural hazard of potentially unprecedented dimension, threatening both life and property. Unlike other natural hazards, however, we can in this instance, using current space technology, both predict and prevent the occurrence of such a disaster... NEOs are part of nature. A NEO impact is a natural hazard in much the same way as are hurricanes, tsunamis, floods, etc. NEO impacts are deceptively infrequent, yet devastating at potentially unimaginable levels... Unlike other natural hazards, however, NEO impacts can be predicted well ahead of time and actually prevented from occurring. If we live up to our responsibility, if we wisely use our amazing technology, and if we are mature enough, as a nation and as a community of nations, there may never again be a substantially damaging asteroid impact on the Earth. We have the ability to make ourselves safe from cosmic extinction.
(Excerpt) Read more at spaceref.com ...
Testimony of Donald YeomansCelestial debris hits the Earth all the time, but the vast majority of it is so small that it does not survive passage through the Earth's atmosphere... The Earth is pummeled with more than 100 tons of impacting material each day but almost all of it is far too small to cause anything other than a harmless meteor, or shooting star, or the occasional fireball event... While a basketball-sized object strikes the Earth's atmosphere daily, larger car-sized impactors hit only a few times each year, and even these generally break up into smaller pieces as they streak through the atmosphere. Occasionally a fragment of a larger impactor will reach the Earth's surface -- one such hit may have occurred less than two months ago when a reported asteroid fragment perhaps one meter in diameter struck in southern Peru creating a 13-meter crater near Lake Titicaca. Larger impactors with diameters in the 50 to 140 meter range, while they do not usually impact the ground, can result in damaging air blasts that cause significant destruction. For example, on June 30, 1908, an impactor with a diameter of about 50 meters detonated over the Tunguska region of Siberia and leveled trees for 2000 square kilometers. Its impact energy has been estimated at about 10 million tons of TNT explosives (10 megatons or 10 MT), comparable in energy with a modern nuclear weapon. Roughly speaking, PHAs that have diameters larger than 140 m can punch through the Earth's atmosphere and cause regional damage if they strike land or create a harmful tsunami should they impact into an ocean. There are thought to be about 20,000 PHAs in this size range, each with a potential impact energy of 100 MT or more. On average, one of these objects would be expected to strike Earth every 5000 years and therefore would have a 1% probability of impact in the next 50 years. Although their mean impact frequency would be about once every 500,000 years, PHAs larger than a kilometer in diameter could cause global consequences due to not only the extraordinary blast itself (50,000 MT) but also the dust and debris thrown into the air, and the subsequent firestorms and acid rain.
Jet Propulsion Laboratory
Thursday, November 8, 2007
Congressional testimony on Earth-threatening
asteroid deflection technology and mission
Space Ref | 04/07/2004
Posted on 04/07/2004 12:29:08 PM EDT by cogitator
http://www.freerepublic.com/focus/f-news/1113138/posts
Astronaut Asks Congress to Investigate Threatening Asteroid
Space.com | May 19th, 2005 | Leonard David
Posted on 05/20/2005 2:33:56 AM EDT by Termite_Commander
http://www.freerepublic.com/focus/f-news/1406900/posts
Astronauts push for strategies,
spacecraft to prevent cosmic collision
Flagstaff Arizona Sun | 11/06/2005 | Marcia Dunn
Posted on 11/06/2005 8:53:40 PM EST by Graybeard58
http://www.freerepublic.com/focus/f-chat/1517000/posts
Astronaut Seeks Craft to Bump Asteroids
AP via Earthlink | January 23, 2007 | AP
Posted on 01/23/2007 11:52:26 PM EST by John W
http://www.freerepublic.com/focus/f-news/1772659/posts
Asteroid Threat Demands Response, Experts Warn
New Scientist | 2-17-2007 | Ivan Semeniuk
Posted on 02/17/2007 2:41:10 PM EST by blam
http://www.freerepublic.com/focus/f-news/1786624/posts
U.N. Urged to Take On Asteroid Threat (2036?)(Freep Poll)
AOL News/Reuters | February 18, 2007 | Irene Klotz
Posted on 02/19/2007 4:35:54 AM EST by 2ndDivisionVet
http://www.freerepublic.com/focus/f-news/1787225/posts
UN urged to take action on asteroids
National Post | Feb 19, 2007 | James Clwan
Posted on 02/19/2007 2:07:31 PM EST by Big Mack
http://www.freerepublic.com/focus/f-news/1787434/posts
Would The United Nations Stop An Asteroid?
Creators Syndicate | February 21, 2007 | Ben Shapiro
Posted on 02/21/2007 8:01:08 AM EST by UltraConservative
http://www.freerepublic.com/focus/f-news/1788448/posts
Nice graphic, thanks Fred:
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Any body believing that government is going to develop an efficacious, robust, thrifty and timely Asteriod defense system is smoking rope. I propose setting up a for profit corportation and charging an insurance fee to each nation, no fee, no protection.
Maybe la cosa nostra can run it.
KD, a space ping?
My dirty little meglomaniacal secret is that whoever controls this Space Protection Corp, is instantly the most powerful military force on the Planet, and master of the Universe.
I'm a little mystified that the writer, or possibly the editor, didn't include the fact that the late Gene Shoemaker was *the* geologist who brought impacts of this kind into mainstream geology; and of course, even more mystifying, is the lack of mention of the SL-9 comet impacts on Jupiter, which buried the derision of the simpletons who derided the role of impact, yet considered themselves scientists.What To Do Before the Asteroid StrikesAmid fears about global warming, terrorism, disease, and nuclear proliferation, the threat of rocks from space may seem more the province of bad Hollywood movies than front-page news. Even professional astronomers have long dismissed asteroids as undistinguished flotsam and jetsam, would-be planets that circle the sun endlessly in a belt between Mars and Jupiter. Their derision left the field of asteroid hunting largely to amateurs and eccentrics.
by Andrew Lawler
Thursday, November 1, 2007
Only recently have researchers glimpsed the dangers lurking in our deceptively quiet neighborhood. "Impacts are a fact of life in the universe, but when we look up, it's not what we see," says Carolyn Shoemaker, who, together with her late husband, Gene, pioneered ways of spotting asteroids and comets. It was geologists who first noticed the evidence of huge impact craters on Earth that had formed long after the solar system settled into its present form, prompting biologists to speculate on whether those collisions dramatically altered life's evolution. Later, using new technologies on the ground as well as robotic spacecraft, scientists like Shoemaker started to track, catalog, and closely examine the objects.
Barringer Meteor Crater in Arizona is the scar of an asteroid hit from less than 50,000 years ago. (Image courtesy of NASA)
;’)
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