The big question: Did they leave artifacts behind for us to find?
In the three-way horse race to prove that biology is not just a terrestrial aberration, there's one steed that many people ignore: sampling the air of distant planets to see if they contain the exhaust gases of life, or in the jargon of astrobiologists, biosignatures.
"We really do know that pretty much every star in the sky hosts at least one planet," says astronomer Adam Frank.
Scientists argue "early Armageddon" snuffs out alien life before it has a chance to evolve.
Just as MS DOS was a good operating system for the Intel x86, but even Bill Gates wouldn't use it now, our understanding of religion also needs to upgrade as human progress continues. But lets not just assume that "software upgrades" haven't already been taking place
Until then! (Story continues below photo.) Robert Wadlow (1918-1940), the tallest man who ever lived. Ultimately, Shostak
The study was published online on April 9 in the journal Nature. As Geoffrey Blake, a planetary scientist at the California
Last month Russian scientists said they discovered sea plankton on the International Space Station that might be alive and thriving. NASA shed doubt on the discovery, and little has been said since. However, the German Aerospace Center recently responded to questions on the issue, confirming the discovery of "bacterial DNA" but casting doubt on other aspects of the Russian report.
I'd welcome an alien in my church pew any Sunday, as an astrobiologist who is also a pastor. However, none have shown up as yet.
For decades, at least, astronomers will be unable to know that an Earth twin's spectrum that shows signs of both oxygen and methane comes entirely from a single object. In other words, even if we find such a tantalizing signal, we might not know that we've found life on the Earth twin.
Aliens almost definitely exist. “The chances of finding it I think are good and if that happens it will happen in the next
Electron micrographs of Bacillus pumilus SAFR-032 spores on aluminum before and after exposure to space conditions. [Reproduced
Earth’s atmosphere is heavy—it’s what keeps water from flying off into space. So astronomers looking for alien worlds that
Hollywood is in the midst of a science-fiction boom, yet few of its sci-fi movies are based on real science. That's a shame, because the scientific discoveries emerging from NASA these days are as exciting as any Hollywood blockbuster.