英语听力：自然百科 探索世界奥秘之Life On Mars(火星生命)Unit02（在线收听）

I think it is exciting. Because it would imply that if life arose independently on Mars. The implication is that life is pervasive throughout the universe.

This is why Mars has so obsessed scientists. If life has arisen independently on the planet just next to us, then the chances / must be that life be everywhere, in which case, we are not alone.

The idea of life on Mars was first popularized by an American astronomer called Percival Lowell in the 1890s. He claimed he could see evidence of a civilization on Mars. The lines crisscrossing its surface he believed were not geological accidents, but canals linking Martian cities.

Gee, hwish!

Lowell's vision inspired a global obsession with aliens, and spawned thousands of movies about little green men.

But in July 1965, reality intruded. Mariner 4 became the first probe to fly by Mars and photographe it. At last, the world would see what the land of the little green men really look like.

"When Mariner 4 flew by Mars, it just took a few pictures with a very coarse-grained television camera. And what it showed was a surface that could've been the moon. Clearly there was no civilizations, no canals, probably not even trees and insects. It was really a bleak landscape that was being photographed there. It really gave the impression that Mars was dead, and has always been dead since its early history. And they really dashed the hopes of dreamers thinking that maybe there was life there.

crisscross: to move back and forth through or over

Percival Lowel: American astronomer. He founded the Lowell Observatory in Arizona (1894), where his studies of Mars led him to believe that the planet was inhabited

dash: To destroy or wreck