VAIL, Colorado - NASA has begun a fact-finding appraisal of how best to detect, track, catalogue and characterize near-Earth asteroids and comets--and what can be done to deflect an object found on course to strike our planet.

The need to prepare is highlighted this week as astronomers watch a large asteroid that will pass close to Earth on July 3.

Selected experts from a variety of fields are here this week at a NASA workshop on Near-Earth Object (NEO) Detection, Characterization and Threat Mitigation. The meeting is a unique, "idea gathering" event being carried out under direction of the U.S. Congress. The intent is to provide lawmakers with an "executable program"--but also one that will clearly need funds to implement that program in an orderly and timely fashion.

NASA is on a fast-track to provide by year's end an initial report to Congress that includes an analysis of possible alternatives that might be employed to divert an object on a likely collision course with Earth.

The U.S. Congress has tagged NASA to use its "unique competence" to deal with the potential hazard faced by Earth from such celestial wanderers, in order to help establish a warning and mitigation strategy.

Another chief agenda item on the table is putting in place the survey skills to spot NEOs equal to or greater than 460 feet (140 meters) in diameter. In plotting out that survey program, the merits of ground-based and space-based equipment are to be mulled over to achieve 90 percent completion of a NEO catalogue within 15 years.

Global...not national problem

This week's gathering is viewed by many as a turning-point in shaping a NEO action plan.

"It is historic in the sense that it's the first time the U.S. government has ever had a formal interest in the problem, in the global problem, that is, in the detection, tracking and beginning to look at the mitigation issues. I think that's very significant," said William Ailor of The Aerospace Corporation and on the workshop's mitigation working group.

Similar in view was Russell Schweickart, former Apollo astronaut and Chairman of the B612 Foundation. This group consists of scientists, technologists, astronomers, astronauts, and other specialists that want to significantly alter the orbit of an asteroid in a controlled manner by 2015.

"This is really the first time that NASA will have ever put the words NASA and asteroid deflection together internally ... so it's a very positive move," Schweickart told in a pre-workshop interview. He later advised workshop participants that "this isn't a national issue...this is a planetary issue."

Schweickart added that, given the likely scenario of decades of warning time, "this is not a last minute search and destroy mission."

Unfriendly fire

There's been no shortage of ideas how to fend off unfriendly fire from the cosmos: laser beams, space tugboats, gravity tractor, and solar sails for example, as well as using powerful anti-NEO bombs, conventional as well as nuclear.

Ailor, also Director of The Aerospace Corporation's Center for Orbital and Reentry Debris Studies, told that creative ways to deflect Earth-harming NEOs are far from being exhausted.

"People have put a lot of concepts on the table over time," Ailor said. "Now we're beginning to try and develop an organized way of looking at those things and finding out which ones are really viable in the short-term, medium-term, and what technologies do we need to protect and develop for the long-term as well."

A key message early in the workshop is that detection of NEOs is a first priority. The on-going, three-part mantra agreed to by attendees is simple and direct: "Find them early...and find them early...and find them early." 

Realistic alternatives

A likely setting is one where a modest Earth impact probability by a NEO is identified decades in advance, then, future mitigation technologies would be most appropriate.

Furthermore, "opportunity science" could be derived from such a response. NASA has an interest in harvesting NEOs for their minerals as well as siphoning from them water to further long-range space exploration goals.

Former shuttle astronaut Tom Jones, taking part in the meeting, has had a long-standing interest in asteroids and told

"The NEO workshop this week is both informative--with the latest NEO data presented by experts in the field--and encouraging as the space agency seems intent on developing realistic alternatives for detecting most of the potentially hazardous NEOs. That's good ... Congress expects NASA to answer the mail on how to deal with NEOs. This meeting is an important move forward in beginning to materially address the hazard."

As if a warning shot of sorts, several workshop attendees made note of next week's close flyby of Earth of asteroid 2004 XP14. Discovered in late 2004, the space rock will slip by Earth on July 3, passing just beyond the Moon's average distance from Earth.