By CHRIS BATEMAN
and the Associated Press
Did you hear a sonic boom early on the morning of Feb. 1?
Or see what might have been the shuttle's trail across the predawn sky?
Or find anything that might actually be shuttle debris?
NASA wants to hear from you: Its Johnson Space Center Debris hotline number is (281) 483-3388. Operators want to hear from anyone who heard or saw anything unusual in the sky just before 6 a.m.
Also, NASA today has asked U.S. Forest service rangers to be on the lookout in this area.
The space agency said rangers should look out for debris in five areas where the search may be limited by isolation and snow accumulation: Calaveras, Tuolumne, Amador, Alpine and Mono counties.
None of the hundreds of possible debris sightings in California or anywhere west of Fort Worth, Texas, have been linked to the breakup of Columbia, investigators said today.
But they said photographs and data suggest the shuttle began breaking up over the western United States.
Andreas Dibbern, who is leading the NASA debris recovery operation in California and Nevada, asked the Forest Service to alert its employees in counties to watch for shuttle remnants.
''We are telling our folks to keep an extra sharp eye out for anything unusual, as they make their normal rounds,'' said Forest Service spokesman Matt Mathes. ''Unfortunately, of course, a lot of the country we manage is high elevation, in very rugged terrain and under snow right now.''
Dibbern's request said NASA would try to make an initial evaluation based on a digital photo of any suspicious object. If it appears to be a portion of the shuttle, or if the experts are unsure, NASA will send a team to the site.
Talking to foothills people who might have seen or heard anything related to the shuttle's disintegration could be crucial to the investigation.
"This is very important," said Doug Kohl of Confidence, an aerospace engineer who worked many years for a NASA-hired space-shuttle-program contractor.