Give consideration to the fact that alien astronomers could have scrutinized Earth for more than 4 billion years without detecting any radio signals, despite the fact that our world is the poster child for habitability.Seth Shostak
Consider: Life arose on Earth close to four billion years ago. Four billion years of slithering, swimming, and soaring life forms. But only in the last 200 thousand years has a species arisen that can fathom the laws of nature and build hardware able to signal its presence.Seth Shostak
Consider: The human genome consists of about 3.3 billion base pairs. Since there are only four types of pair, that amounts to 0.8 gigabytes of information, or about what you can fit on a CD. With a microwave radio transmitter, you could beam that amount of information into space in a few minutes, and have it travel to anyone at light speed.Seth Shostak
Mars still remains the astrobiology community's number one choice for 'nearest rock with life,' but there are many researchers who argue that the moons of Jupiter are better bets. In particular, Europa, Ganymede, and Callisto are all thought to hide vast oceans of liquid water beneath their icy, outer skins.Seth Shostak
I've often fantasized about visiting the Bahamian beach where Columbus first stumbled ashore in 1492. Sadly, no one knows where that beach is. In fact, no one's even sure which island Columbus first encountered (there are three candidates). It's a pity, a disappointment, and a lost revenue source for the Bahamians.Seth Shostak
It will be the mother of all telescopes, and you can bet it will do for astronomy what genome sequencing is doing for biology. The clumsy, if utilitarian, name of this mirrored monster is Large Synoptic Survey Telescope, or LSST. You can't use it yet, but a peak in the Chilean Andes has been decapitated to provide a level spot for placement.Seth Shostak
The bottom line is, like, one in five stars has at least one planet where life might spring up. That's a fantastically large percentage. That means in our galaxy, there's on the order of tens of billions of Earth-like worlds.Seth Shostak
Astronomers still can't decide what the shape of our universe is. Is it closed and finite, which is to say, is there a countable tally of all the galaxies that exist, even beyond the ones we can see? Or is it infinite? The latter possibility is still on the table.Seth Shostak
Diminutive worlds are more likely to be rocky, and lapped by oceans and atmospheres. In the vernacular of 'Star Trek,' these would be M-class planets: life-friendly oases where biology could begin and bumpy-faced Klingons might exist.Seth Shostak
Sure, nobody will make a fortune if we figure out why the Big Bang happened. But just about everyone would like to know.Seth Shostak