Spaceguard: Current Progress and Future Capabilities
By: David Morrison
While the present Spaceguard Survey will be 75% complete by the end of 2004, much bigger survey telescopes such as Pan-STARRS in Hawaii and the DCT at Lowell Observatory are making progress.
At the end of 2003, there were 2600 known Near Earth Asteroids (NEAs), and of these 691 are brighter than absolute magnitude H=18, which is taken to correspond to 1 km diameter. Of these, 131 are classed as PHAs (potentially hazardous asteroids) larger than 1 km. These data are from Alan Chamberlin and are posted on the JPL/NASA NEO Program Office website
For comparison, there are estimated to be a total of 1100 +/- 100 NEAs larger than 1 km. Thus at the end of 2003 we had found 63 percent of these NEAs.
Recently there appears to have been a modest slow-down in the discovery rate of NEAs larger than 1 km, perhaps reflecting the fact that we have already discovered nearly 2/3 of this population group. For the most recent three complete years (2001, 2002, and 2003), the numbers discovered are: 89, 95, and 67, respectively. We can check this effect by noting that the total discovery rate of all NEAs has not changed much, remaining at about 450/yr. Previously, improvements in the search systems more than compensated for the declining number of unknown asteroids bigger than 1 km waiting to be discovered.
The Spaceguard Goal is 90 percent completeness by the end of 2008. This corresponds to discovery of 990 NEAs brighter than H=18 for the nominal population. The survey passed its halfway mark of 495 in mid-2000 (see News Archive note for 08/01/00). The 75 percent objective is 742 NEAs larger than 1 km. If we anticipate 50 discoveries during 2004, then the survey should reach this milestone at the end of this year.
First we find them, then we need to figure out how were going to prevent one from smacking our planet. Fortunately, we are working on the problem, here's a story about the PAN-STARRS telescope, from the previous link-
COMING SOON: PAN-STARRS TO SEARCH FOR KILLER ASTEROIDS
Honolulu Star-Bulletin, 25 April 2004 By Helen Altonn
If one of the thousands of asteroids hurtling through space crashes into Earth, the damage could equal 700 Hiroshima-size bombs blasted at once. The potential danger of a collision with a 198-foot asteroid was pointed out recently to a U.S. Senate science committee by astronaut Ed Lu, who calls Honolulu one of his hometowns. He said there is a 10 percent chance of this happening.
The first warning of a small killer asteroid could come from a special array of four small telescopes planned in Hawaii. The first telescope in the Panoramic Survey Telescope and Rapid Response System, called Pan-STARRS, is scheduled to be operating in two years on Haleakala, Maui, to test the system.
"The project serves as a guardian," said Kenneth Chambers, of the University of Hawaii Institute for Astronomy. Chambers is principal scientist for the first prototype telescope. "We want to find them as far in the future as we can because it's much easier to do something about them," he said.
The full telescope array will either be at Haleakala or Mauna Kea, on the Big Island, depending on environmental and site studies under way. When it is completed, the scientists expect to detect about 100,000 asteroids a month, said UH astronomer Nicholas Kaiser, principal investigator for the estimated $50 million Pan-STARRS project. "Most of those will be harmless," he said. "We're looking for the odd, bad one."
Lu and astronaut Rusty Schweickart urged the Senate committee to use unmanned spacecraft to test methods of bumping an asteroid from an impact course with Earth. Lu said such capability could save the planet if space surveys warn of an approaching asteroid years in advance. [emphasis-ed.]
That is the prime mission of Pan-STARRS, Chambers said, describing it as a "time machine." The goal is to find 99 percent of asteroids that could significantly damage Earth, determine their orbits and predict what they will do in 20 to 50 years, he said.
The system will enable astronomers to detect objects as small as 330 yards in diameter and 100 times fainter than those observed by other telescopes. Instead of looking through telescopes to understand what happened in the past, Chambers said, astronomers will be looking at what will happen in the future. Repeatedly sweeping big patches of sky, he said, "we can find the ones that will be a threat in the future and those that will zoom by but are not going to do any harm, and only get worked up by those that are a threat."
Now someone remind me why we need to spend trillions of dollars going to Mars, but we can only find 1% of Nasa's budget to work on the NEO issue? Anyone? Bueller?
Then tell me what would be the point of having all of these fancy Mars or Saturn programs after our planet is sent back to the dark ages? Not much use in sending back pictures of the surface of Titus if there isn't anyone there to see them.
Don't get me wrong, I don't believe that we should spend ALL of our time and money on the NEO issue, but I most certainly don't think that we are spending nearly enough. This should be priority one for NASA, everything else should be either related or secondary.
And god said -Boom.
Update: Priorities aside, this Picture of Phoebe, one of Saturns Moons, is pretty freaking cool though......