Search for E.T.
But not everyone buys one popular physicist's downbeat argument.
No one has found E.T. yet, but we may be getting closer.
E.T., phone China.
Columbia University astronomers say their laser plan would work, but others aren't so sure.
WHAT'S HAPPENING
The European-Russian mission is the latest to seek out Martian life.
It will be able to detect and receive signals from outer space and help search for extraterrestrial intelligence.
Scientists argue "early Armageddon" snuffs out alien life before it has a chance to evolve.
Acclaimed scientist says it may be disastrous to reach out and touch aliens.
The new planet is the most like Earth of any discovered so far
