The House and Senate are holding hearings this week on the threat of asteroids to Earth. Scientists are calling for continued funding and support for NASA satellites and observation programs that look for near-Earth objects.
They warn the Earth could be facing an Armageddon-like scenario this century, adding that there is almost no way to stop asteroids and debris from hurtling toward the planet.
On Tuesday, lawmakers on the House Science Committee asked NASA Administrator Charles Bolden what his agency could do if a large asteroid headed for Earth was discovered with just weeks before impact.
"The answer to you is, if it's coming in three weeks, pray," he replied.
Scientists say the only way to protect Earth is to have decades of advance warning of a major object heading our way.
"With 10, 20, 30 years notice, it is fairly easy to deflect an asteroid," Dr. Ed Lu, a former NASA astronaut and CEO of the B612 Foundation, testified before a Senate panel Wednesday.
Witnesses told the panel that without increased funding for NASA and support for satellites and observation programs we could never detect asteroids in time to prevent mass casualties.
"The ones that I've been talking about, had that happened over a city -- let's say NYC -- we would have 7 million casualties, at least. Whatever the population of NYC is, they would be gone," Dr. Lu said.
So far, NASA has detected only about 10 percent of near-Earth objects that are wider than 87 miles across. It's estimated that hundreds of thousands may remain unknown.
Scientists say that while the odds of an asteroid strike causing mass casualties and destruction are very small, the consequences are so large that the risk must be taken seriously.
"I just want to again point out that there is a 30 percent chance that there is a 5 mega ton or so impact that's going to happen in a random location on this planet this century, so this is not hypothetical," Dr. Lu said.
In 2005, Congress gave NASA a deadline to detect 90 percent of these space rocks. NASA said because of budget cuts they won't meet that deadline until at least 2030.