Even if a 100-m asteroid hit the Earth it would be a catastrophe. They come a lot oftener than every 65,000,000 years.

Possibly every few thousand years, if this thread is right:
http://setiathome.berkeley.edu/forum_thread.php?id=35502#458184

Even if a 100-m asteroid hit the Earth it would be a catastrophe. They come a lot oftener than every 65,000,000 years.

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Ulli you are quite right to be concerned. I would be interested in comments from some of the other Seti@home folks about this issue. The ability of Arecibo as well as other large radio telescopes worldwide to detect, analyze and monitor near earth asteroids that might pose a collision threat is critical. I doubt that we want to be smacked back to pre-dinosaur days.

Don't think we need to worry about that. Last time a giant asteroid hit was 60 million years ago. What are the odds that another will hit within our lifetimes? Maybe 1 in 20,000? Looking for Earthbusters is a waste of money, as far as I'm concerned; atleast for the near-term.

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Ulli you are quite right to be concerned. I would be interested in comments from some of the other Seti@home folks about this issue. The ability of Arecibo as well as other large radio telescopes worldwide to detect, analyze and monitor near earth asteroids that might pose a collision threat is critical. I doubt that we want to be smacked back to pre-dinosaur days.

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this is a google Translation

The USA make all listening unit deaf mute

Of Thorsten Dambeck

The Arecibo observatory in Puerto Rico, location of the largest radio dish of the world, stands before from: The backers turn to new projects. Researchers warn of dangerous consequences. World-wide no equivalent replacement exists, in order to discover Asteroiden with course on earth.

Probably no scientific mechanism was ever blown up with a such bang effect in the Nirvana: No smaller one than James bond did gymnastics to the final of “GoldenEye” by the enormous 300-Meter-Schüssel of the Arecibo radio telescope in Puerto Rico. Where otherwise planet researchers scan Asteroiden with radar jets and after star corpses listens to astronomers, “007” brought its adversary, to the abtrünnigen “006”, to the distance. For the telescope the victory of the good one ends however fatal: The antenna exploded.

With less rabiaten means science politicians could obtain soon the same effect: The means for the world-wide largest radio telescope dish are to be cut. 2011, approximately 48 years after their opening in November 1963, could be shut down the Arecibo telescope. The American National Science Foundation (NSF), which the observatory maintains, plans already for the time thereafter. Instead of the legendary antenna new projects are to abhorchen like the Atacama Large millimeter array in Chile the radio sky in the coming decade. The NSF wants alone into this project 500 million dollar to put, the financing of Arecibo is against it to run out. Thus it recommends the responsible NSF Kommitee anyhow.

As radar device unequalled

For the new project inevitably shortening would have to be accepted with older mechanisms - otherwise the operating cost of a daily ate the entire budget, means Michael Turner, astrophysicist at the University OF Chicago. A similar fate met also smaller national observatories in Europe, took up than the common European south observatory (Eso) their enterprise in Chile.

Now if no new sponsors should step on the plan for Arecibo, the locking is forthcoming starting from 2011. The same fate threatens the Very Long cousin LINE array, a group out crosswise via the USA distributed 25-Meter-Radioteleskopen.

Some astronomers run however storm against these plans, because Arecibo has the rare ability to function also as enormous radar device. A “singular mechanism” is threatened from the locking, said about Donald Campbell. The US astronomer of the Cornell University scanned the polar areas of the moon with the Arecibo antenna recently for ice. Only the California gold clay/tone antenna offers one into comparable radar capacity, however with clearly smaller sensitivity.

Planetary safety risk

But with the coming decision for or against Arecibos is a matter it did not only continue using of scientific questions. Because the giant radar is particularly important for the exploration of celestial objects, which move us still closer on the Pelle than our own moon: near earth Asteroiden. They originally originate from the rock rubble belt between Mars and Jupiter. Small and larger breaking into their courses again and again leave and in the internal solar system are diverted. Some come thereby on collision course with the earth.

Still nobody knows whether and when it comes in more near future to an impact. But the systematic search of the past years today nevertheless furnished to 831 suspicious objects, to which is to be thought capable of. Larger breaking into with diameters starting from ten kilometers are considered than planetary safety risk: A collision with the earth would entail a global disaster. 65 million years ago the end of the dinosaurs and many further kinds could so have gone.

Hundreds of Asteroiden took astronomers with the Arecibo telescope in the radar visor. If it goes to the NSF, thereby conclusion would soon be. “From” threatens a promising golden age of the study of near earth Asteroiden, warned Steven Ostro of the jet Propulsion Laboratory of NASA in the discussion with MIRROR ON-LINE ONE. With particularly close Vorbeiflügen of the cosmic projectiles Ostro sat for many years with the antennas in Arecibo and gold clay/tone in the first row: By precise measurement of their radar reflexes spectacular Porträts of the umherschwirrenden rubble arrives to it.

Under favorable conditions the Arecibo antenna knows still surface details of up to ten meters of diameters constituted. Particularly for the precise forecast of future probabilities of collision radar is irreplaceable. Ostros so far last caper was the observation of the bizarren double Asteroiden 1999 KW4, whose hectic turn could tear a breaking into into pieces.

Radio programs for Aliens

Scientific successes arrive to distant celestial objects in Arecibo also with much far: Beginning of the nineties found a researcher team assistance of the giant dish the first planets outside of our solar system. They circle approximately 2600 light-years far away from the earth around a Pulsar, a rotary Relikt to supernew facts. Such neutron stars send bundled radio jets in the universe, which are caught of radio telescopes as in Arecibo as periodic pulses.

The course analysis of another pulse acre, for which with a normal star a double system forms, was particularly informative. The two US researchers Joseph Taylor and Russel Hulse measured his period in Arecibo and found strong indications for the mysterious gravitation waves predicted by Einstein. The researchers received for it 1993 the Nobelpreis. Beyond that the Arecibo antenna became as listening organ of the Seti project (“search for extraterrestrial Intelligence”) admits, which looks for radio messages of extraterrestial civilizations. In “Contact” with Jodie Foster in the main role had the observatory a second large film appearance. Also human messages were sent from Arecibo into the universe.

While such investigations are possible also with the coming generation of radio telescopes, it behaves in things Asteroidenforschung differently: None of the existing or new plants can measure in punkto radar with the Arecibo dish. That could have quite unpleasant consequences for the earth, warns NASA researcher Ostro: “A Asteroid on collision course with the earth should be discovered, a diverson of the object without previous radar investigations will probably fail. in our century”

the original came from here in German

Hit me

Greetings from Germany NRW
Ulli