Washington: They came from Mars, not in peace, but in pieces. Scientists are now confirming that 15 pounds of rock collected recently in Morocco fell on Earth from Mars during a meteorite shower last July.

This is only the fifth time in history that scientists have chemically confirmed Martian meteorites that people witnessed falling. The fireball was spotted in the sky six months ago, but the rocks were not discovered on the ground in North Africa until the end of December.

This is an important and unique opportunity for scientists trying to learn about Mars' potential for life. So far, no NASA or Russian spacecraft has returned bits of Mars, so the only samples scientists can examine are those that come here in meteorite showers.

Scientists and collectors are ecstatic, over the fact that the rocks are fetching big bucks because they are among the rarest things on Earth and rarer even than gold. The biggest rock weighs more than 2 pounds (1 kilogram).

"It's Christmas in January," said former NASA sciences Chief Alan Stern, director of the Florida Space Institute at the University of Central Florida. "It's nice to have Mars sending samples to Earth, particularly when our pockets are too empty to go get them ourselves."

A special committee on Tuesday of meteorite experts, including some NASA scientists, confirmed test results that showed the rocks came from Mars, based on their age and chemical signature.

Astronomers think millions of years ago something big smashed into Mars and sent rocks hurtling through the solar system. After a long journey through space, one of those rocks plunged through Earth's atmosphere, breaking into smaller pieces.