more:ABC News: Satellite Collision Puts Hubble at RiskThe already hobbled Hubble Space Telescope could be further harmed by space debris from Wednesday's unprecedented satellite collision, a chief NASA scientist told ABC News.
There has always been a small risk that Hubble and other spacecraft could be damaged by the thousands of pieces of junk floating through space.
But now that the space telescope is orbiting 75 miles below where the collision took place, experts say the risk is much greater.
"Clearly debris from the event is going through the altitude that the Hubble flies, so we're going to be looking at what is the new risk to Hubble," said Nicholas Johnson, chief scientist at the Orbital Debris Office at NASA's Johnson Space Center.
When two large satellites crossing paths at hypervelocity -- each weighing more than 1,000 pounds and going 17,500 miles an hour -- collided Wednesday over Siberia at an altitude of 491 miles, it was the first time there had ever been such a crash in space.
No one knows yet why the Iridium communications satellite and an old Russian Cosmos satellite ended up on a collision course.