Quotes from Seth Shostak

Recent results from astronomers who study the occasional gravitational lensing of unknown worlds by intervening stars suggest that orphan planets could be at least as numerous as the stars. In other words, there could be hundreds of billions of orphan worlds shuffling through our galaxy.

The mission of NASA's Kepler telescope is to lift the scales from our eyes and reveal to us just how typical our home world is. Kepler operates by measuring the dimming of stars as planets pass ('transit') in front of them. It has found thousands of previously unknown worlds.

The cosmos is three times as old as Earth. During most of creation's 14 billion year history, our solar system wasn't around. Nonetheless, the early universe still had the right stuff for life, and contained worlds that were just as suitable for spawning biology and intelligence as our own.

The overwhelming bulk of the cosmos is deathly quiet. But here and there - on worlds where matter is thick and conditions are right - noises are commonplace. And in some cases, these noisy worlds may ring with the sounds of life - the bleats and bellows of creatures we have never seen, but may someday discover.

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.

The usual metric for whether a planet is habitable or not is to ascertain whether liquid water could exist on its surface. Most worlds will either be too cold, too hot or of a type (like Jupiter) that may have no solid surface and be swaddled in noxious gases.

The math is dead simple: it seems that the frequency of planets able to support life is roughly one percent. In other words, a billion or more such worlds exist in our galaxy alone. That's a lot of acreage, and it takes industrial-strength credulity to believe it's all bleakly barren.

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.

The Moon stabilizes Earth's obliquity. Well, almost. The tilt actually varies between 22 and 24.5 degrees - and the variation is enough to induce such environmental inconveniences as the occasional ice age. Without the Moon, it might be much worse.

In archaeology, context is the basis of many discoveries that are imputed to the deliberate workings of intelligence. If I find a rock chipped in such a way as to give it a sharp edge, and the discovery is made in a cave, I am seduced into ascribing this to tool use by distant, fetid and furry ancestors.

Given the tendency of many to picture God's realm as somewhere high above Earth - an idea that sounds suspiciously like the Greek stories of deities perched on inaccessible mountain tops - it may seem plausible to assume that astronomers have special insight. Well, of course they don't.

As far as I can tell, the only unambiguous consequence of the claimed invasion of Earth by beings from another star system has been a nonstop torrent of TV specials. So if you're one of the many who believe the aliens are here, you really do have to admit this: They're the best houseguests ever.

The total funding of SETI (the Search for Extraterrestrial Intelligence) in the U.S. is 0.0003 percent of the tax monies spent on health and human services. And it's not even tax money. The SETI Institute's hunt for signals is funded by donations.

The total number of people that do a job that has the same description as mine in the entire world is fewer than 10. There's a lot of effort looking for life in space - that's a lot of what NASA does, but they're not necessarily looking for the kind of life that can hold up its side of a conversation.

Since the Renaissance, a concept called 'progress' has been baked into our society. Progress - founded on an accumulation of knowledge through experience (and in the case of science, through experiment). To build on the past rather than endlessly relive it. That's what separates us from the beasts.

You may not see massive UFO exhibits at your local science museum, but there's no dearth of saucer stories infesting my email. Every day, I receive several reports of alien sightings, extraterrestrial plans for Earth, and agitated screeds about the reluctance of scientists to take the whole subject seriously.

Hollywood usually guesses that extraterrestrials would only be interested in one of three things: (1) They want to breed with us, because their own reproductive machinery is on the blink; (2) They want Earth's resources; or (3) They want the Earth. All of it.

Despite the impression you may have from watching too much TV, movies are not about reproducing reality. They're about telling stories.

Sure, our three-pound brains might be inadequate to understand the universe. But perhaps they're just good enough to build something that can.

While I have always thought that the motivation for looking for E.T. was both self-evident and patently worthy, it's possible that I'm a victim of my own job description. Others don't inevitably agree. Some will opine that there are better ways to spend the money.

If aliens are really hanging out in our 'hood, it's hard to imagine any other fact more worthy of study. If not, then why does such a large fraction of the populace insist on believing they're here?

It's hard to imagine anything more interesting than learning how we're woven into the enormous tapestry of existence. Where did our universe come from? How special is our world, and how special are we? We allocate tens of billions of dollars annually to NASA, NSF and academia in search of the answers.

Scientists - who prefer explanations subject to laboratory tests - figure that everything we see today was as inevitable as wrinkles, once the Big Bang established physics. Stars and planets were cooked up as huge clouds of matter collapsed and coalesced.

'Battleship' is not a film that Francois Truffaut would have made. Nor would any of those other namby-pamby European directors. Nope, this picture eschews that Continental obsession with small stories, set in quaint towns filled with pockmarked folk doing their banal things.