Seth Shostak quotes:

Forecasting Armageddon has become trendy of late, with a great deal of attention being given to an interpretation of the Mayan Calendar suggesting that Mother Earth is destined for doom in December of 2012.

The split between religion and science is relatively new. Isaac Newton, who first worked out the laws by which gravity held the planets and even the stars in their traces, was sufficiently impressed by the scale and regularity of the universe to ascribe it all to God.

Mining asteroids is a well-oiled trope of science-fiction. But someday, actually doing it will make economic sense. Many of the essential metals of our society, such as platinum, copper and zinc, are rapidly becoming scarce. The asteroids might offer a replacement supply, providing the materials our descendants will need for a high quality life.

Five centuries from now - barring unimaginable catastrophe - the moon will be developed real estate. There's economic incentive to exploit the moon - the helium-3 will be useful in powering fusion reactors, and the rare earth elements could supplant the limited terrestrial supply of these materials.

It's worth noting that invoking God as the entity who set our universe in motion isn't contradicted by the data. Of course, scientists would say the supreme being hypothesis is faith, and outside the realm of science - that it's not amenable to experiment. But we currently have the same problem with the notion of parallel universes.

The principal reason for the universe's poker face is that its constituents are far away. Stars careen through space, and galaxies spin at speeds thousands of times faster than a jet plane. But given their distance, you'd need the patience of Job to notice much change in their appearance or position.

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.

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.

Consider that the overwhelming majority of those 40,000 near-Earth asteroids are small enough to fit on the parking lot at the mall. And while these rocky runts won't cause Armageddon, they could still flatten such popular hominid hangouts as Manhattan or downtown Des Moines.

Neil Armstrong was no Christopher Columbus. In most respects, he was better. Unlike the famous fifteenth century seafarer, Armstrong knew where he landed. He also spent his time in public service, not in jail, and his passing was marked by world-wide encomiums. He ended his days as a celebrated explorer rather than a royal inconvenience.

Ever since the infamous quiz show scandals of the 1950s, the feds had insisted that TV game shows be honest - or that at least they didn't cheat. So as a 'Dating Game' bachelor, I didn't know what I was going to be asked. The other bachelors and I were required to concoct our answers in real time.

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.

Many people suggest using mathematics to talk to the aliens, and Dutch computer scientist Alexander Ollongren has developed an entire language (Lincos) based on this idea. But my personal opinion is that mathematics may be a hard way to describe ideas like love or democracy.

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.

On Mars, where the air is spare - a hundred times less dense than on Earth - someone could hear you scream. But you'd have to really strain to get anyone's attention. On the Red Planet, where the wind is high-pitched and faint, even a symphony orchestra will sound as thin as cheap gruel.

There will be an end point to how good TV pictures can get. The boob tube has hugely benefited from the rapid advance of digital electronics. Consequently, the strategy for hardware has changed. In the old days, sets had to be as simple as Elmer Fudd to keep them inexpensive. All the technical 'smarts' were at the transmitter end.

Look, science is hard, it has a reputation of being hard, and the facts are, it is hard, and that's the result of 400 years of science, right? I mean, in the 18th century, in the 18th century you could become an expert on any field of science in an afternoon by going to a library, if you could find the library, right?

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.

While it may be disappointing, I have to confess to people who ask for my insights on the meaning of it all that astronomy doesn't provide any clearly useful data on matters of sin and souls.

A practical way to travel between the stars is a must-have for space opera, and a sine qua non for our frequently vaunted future as a galactic society.

Studying Sol's interior by looking for analogous patterns on its incandescent face is known as helioseismology, an active - if largely unpronounceable - research area that uses sound as a probe of our home star.

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.

America's popular heroes have seldom been its great thinkers, and even less its scientists. The success of TV's 'Big Bang Theory,' which seems to give the lie to this claim, is more the exception that proves the rule.

Are two eyes, four appendages and an upright posture really essential for any creature that can ace the galactic SAT's? Maybe not. In fact, I'd venture that any aliens we ever detect or (less likely) encounter will look quite different than this self-referential stereotype.

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.

In the four years since its launch, Kepler has chalked up 122 new and confirmed planets. It's also caught the scent of nearly three thousand additional objects, of which probably 80 percent or more will turn out to be other-worldly orbs.

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.

In the 19th century, if you had a basement lab, you could make major scientific discoveries in your own home. Right? Because there was all this science just lying around waiting for somebody to pick it up.

Like prospecting in the 19th century, reconnaissance of the asteroids would of necessity take place in an arena where trouble is likely and help is distant. Heroic stories of individual triumph and failure, set on landscapes never seen by humankind, are in the cards.

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.

The stars look the same from night to night. Nebulae and galaxies are dully immutable, maintaining the same overall appearance for thousands or millions of years. Indeed, only the sun, moon and planets - together with the occasional comet, asteroid or meteor - seem dynamic.

The majority of my UFO diet consists of reports describing suspected encounters. This is not surprising, as there are thousands of sightings annually. The emailer has seen something unusual in the sky that he interprets as probable evidence of alien presence.

What was there before the Big Bang?' That's a question that both kids and adults love to pose to anyone who seems sympathetic. After all, if the universe has only been around for roughly 14 billion years, isn't it legitimate to ask what was in existence before the mother-of-all-events cranked up the cosmos?

The era during which only governments could put hardware on the Moon is coming to an end. There are 26 private teams competing for the $30 million Google Lunar X-Prize - to be awarded for sending a robotic spacecraft to this nearby world that can roam at least 500 meters, and send back data such as a photo.

When I was a kid, which was just after Edison invented moving pictures, there were films that involved aliens coming to Earth for bad purposes.

Any beings advanced enough to traverse interstellar distances are at least a thousand years beyond our technical level. Spending gobs of time examining our missiles is equivalent to sending the Air Force back to the Middle Ages and insisting they examine the chain mail factories.

Clearly, enriching the cosmos with heavy elements takes a while. So there's inevitably an interval between the sterile aftermath of the Big Bang and a time when the cosmic chemistry set had enough ingredients to make rocky planets (and squishy biology).

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.

By 2020, most home computers will have the computing power of a human brain. That doesn't mean that they are brains, but it means that in terms of raw processing, they can process bits as fast as a brain can. So the question is, how far behind that is the development of a machine that's as smart as we are?

In a movie, it's often important to have aliens whose gestures and facial expressions can be 'read' by humans. And in the days before sophisticated computer animation, most extraterrestrial bit players were guys in rubber suits. Such practical considerations forced Hollywood's hand when it came to aliens - they look like us for good reasons.

Our computers double in capability on time scales of only a few years. It's hardly outrageous to believe that we will successfully develop thinking machines within a handful of decades, or at most a century or two. If that happens, these artificial sentients will quickly leave us behind.

Plate tectonics is not all havoc and destruction. The slow movement of continents and ocean floors recycles carbon dioxide dissolved in the oceans back into the atmosphere. Without this slow speed carbon cycle, Earth's temperatures would cool dozens of degrees below your comfort zone.

Every day, the temperature of Sol's surface increases by five billionths of a degree, a change of no consequence for thousands of millennia to come. But a few hundred million years from now, barring a fix by our descendants, this relentless heating will substantially change Earth's biosphere in ways that might not be survivable for us.

Today's voguish threats, including climate change, population growth, massive war, and resource depletion, are all amenable to a fix if we act prudently. And even if we don't, these problems are incapable of obliterating all of humanity, let alone destroying the Earth. No, the real End of Days will happen slowly, as the Sun ages.

It's easy to reckon that the oomph to hurl even a Smart Car-size spacecraft to another star at, say, 20 percent the speed of light (and land it when it arrives) is the energy contained in 50 billion gallons of gasoline. The tank's not big enough.

The bottom line is that finding orphan planets - small, faint, and located who-knows-where - is not for the faint of heart. The task is comparable to observing a match flame at the distance of Pluto. The WISE satellite, a hi-tech, space-based infrared telescope especially suited for such work, has found only a few.

Disasters happen. We still have no way to eliminate earthquakes, wildfires, hurricanes, floods or droughts. We cope as best we can by fortifying ourselves against danger with building codes and levees, and by setting aside money to clean up afterwards.

According to 'Star Trek' mythos, Starfleet Command - operational headquarters for a flotilla of craft that keep the cosmic peace - is located in San Francisco's Presidio, in the shadow of the Golden Gate Bridge (still carrying traffic, even in the 23rd century).

Thanks to the fact that the Earth isn't a perfect sphere, and invoking a bunch of Newtonian physics, you can deduce that our planet wobbles, too, taking roughly 26,000 years to trace out a small circle on the sky, a phenomenon known as precession.

When I graduated high school, nearly a half-million people subscribed to 'Popular Electronics' magazine. Soldering up some radio or hi-fi amplifier on the basement workbench was not just a personal passion - a lot of young people were doing the same. The magazine expired in 1999 for lack of interest.

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.

There's no doubt that the Moon is more than a handy night light and a hair restorer for werewolves. It's responsible for the substantial amplitude of earthly ocean tides. These are of obvious influence if you're a geoduck, a type of clam that people dig up at low tide.

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.

It bears mentioning that the Milky Way is only one of 150 billion galaxies visible to our telescopes - and each of these will have its own complement of planets.

The central region of the Milky Way, known as the bulge, is stuffed with literally tens of billions of stars. And most of these are old - considerably older than our Sun or its neighbors - because this part of the galaxy formed first. Consequently, bulge stars are generally deficient in heavy elements.

Estimates are that at least 70 per cent of all stars are accompanied by planets, and since the latter can occur in systems rather than as individuals (think of our own solar system), the number of planets in the Milky Way galaxy is of order one trillion.

While human space travel is daunting, machines - with their indefinitely long lifetimes - could travel the galaxy. It might make little difference to them that bridging the distance from one star to the next could take hundreds of thousands of years or more.

We've accounted for 95 percent of all the stars in the Milky Way. The other 5 percent are big, bright stars - the kind that dominate the night sky, but are lamentably both rare and short-lived. If biology's your thing, you can forget those guys.

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.

Judging by informal observation, most young Americans burn up their spare time buffing their emotional IQ and self-esteem with social media and non-stop texting. That's great for eye-thumb coordination, but what about the satisfaction of actually making something?

It's hardly a secret that I'm skeptical of declarations that the aliens are out and about on our planet. Still, I try to answer every one of these mails and phone calls because, after all, it's not a violation of physics to travel from one star system to another.

Very few societies on Earth developed science as we know it today. On the other hand, the number is not zero - the Greeks, the Chinese, and the Maya did, among others. Once invented, science proved so useful that it spread like mold on a petri dish.

NASA's Office of Commercial Exploration has been concerned about protecting the landing zones where humans first walked on the Moon, and one of my colleagues, ecologist Margaret Race, has been part of their deliberations.

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.

Ever since the Second World War, television signals (as well as FM radio and radar) have served as Homo sapiens' emissaries into deep space. High-frequency, high-power broadcasts have filled an Earth-centered bubble more than 60 light-years in radius with signals.

Some pundits have proposed that the aliens have come here to breed with us. Apparently, too much bike riding or something similar has rendered them incapable of reproducing within their own species. But do extraterrestrial infants toddle through your neighborhood?

Sending greeting cards to aliens is hardly a new idea. In 2005, Craigslist solicited messages for broadcast to space by a transmitter in Florida, and in 2008, NASA beamed a Beatles song to the North Star (Polaris), on the assumption that any putative Polarians would appreciate the Fab Four's 1960s-genre compositions.

When it comes to brains, size matters. It's not all that matters, of course. Whales and dolphins have brains that are larger than humans', but few of the flippered and fluked set win tenure at Stanford. Our brains are the largest in proportion to body size, and they're also highly sophisticated.

The Moon is a ball of left-over debris from a cosmic collision that took place more than four billion years ago. A Mars-sized asteroid - one of the countless planetesimals that were frantically churning our solar system into existence - hit the infant Earth, bequeathing it a very large natural satellite.

Jupiter, a world far larger than Earth, is so warm that it currently radiates more internal heat than it receives from the Sun.

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

Clearly, unless thinking beings inevitably wipe themselves out soon after developing technology, extraterrestrial intelligence could often be millions or billions of years in advance of us. We're the galaxy's noodling newbies.

In days gone by, scientists would speak solemnly about our solar system's 'habitable zone' - a theoretical region extending from Venus to Mars, but perhaps not encompassing either, where a planet would be the right temperature to have liquid water on its surface.

If the cosmos isn't finite, then far, far away, floating duplicates of your brain - with all its experiences, thoughts, and emotions - are occasionally (and temporarily) thrown together by the random combining of atoms. Such 'Boltzmann brains,' as they're called, are a disturbing consequence of an unlimited universe.

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.

Once typecast as the indispensable altarpiece of a well-appointed living room, TVs have infected every human environment. The average American household has more television sets than people.

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.

The space elevator's not just another competitive technology, promoted by people who simply like the idea of diminishing the luster of the thrusters. It would open wide the doors to space.

Everything you see is filtered through your visual system (imperfect) and your brain (also imperfect, despite what your mom told you). Witness testimony is the worst kind of evidence in science.

Eternal inflation,' as it's called - the endless generation of new universes - may be a hyper-cosmic imperative. It seems that it must happen.

Television is ephemeral, a fact that some will find reassuring. But earthlings will continue to pump the kilowatts into the ether. And eventually, when those signals have washed over a few hundred thousand star systems, someone may notice.

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.

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.

I think a lot of kids are interested in two science subjects: dinosaurs and aliens. The reason is almost genetic; we're hard-wired to be interested in things that might be a little dangerous.

In 1908, there was a persuasive demonstration of the power of high-speed, low-mass asteroids in rural Siberia. The Tunguska impactor iced millions of pine trees and about a zillion mosquitoes - and was no larger than an office building.

Here's a news flash: scientists can be wrong. That's no big deal (unless the scientist is you), since research is self-correcting. Consequently, most errors by scientists become historical curiosities, with little long-term importance.

The limitless content of our universe might be only one instance of a large (and possibly infinite) number of other universes.

I studied Latin in high school, and I was reading stuff from Cicero. And that signal took a few thousand years to get to me. But I was still interested in what he had to say.

It seems that 'rocket scientist' is a job category that's here for the long haul, like 'mortician.' But all this activity masks an important point: rockets are not a terribly efficient way to lift things into space.

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?

Planets that don't currently sport plate tectonics, such as Venus and Mars, are scarcely habitable. Tectonics might be a requirement of any world that aspires to a rich diversity of life.

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.

If this is the only planet on which not only life, but intelligent life, has arisen, that would be very unusual.

[O]ne might ask why, in a galaxy of a few hundred billion stars, the aliens are so intent on coming to Earth at all. It would be as if every vertebrate in North America somehow felt drawn to a particular house in Peoria, Illinois. Are we really that interesting?

We're hard-wired by 200,000 years of evolution to be sensitive to the idea that someone might be watching us. They might be predators, after all. An uneasy feeling is perfectly natural if you suspect that someone has you in their ocular sights, whether it's a ghost or just some guy at the bus stop.

Even if the Moon didn't exist - even if it had been vaporized billions of years ago by cantankerous Klingons - there would still be (somewhat lower) tides raised by the Sun. For creatures dependent on the oceans' ebb and flow, life could go on.

Mountains aren't eternal: even the most imposing massifs are smoothed away by weathering in a few hundred million years or less. Plate tectonics makes new ones, and without it, our future would be flat.

What's a space elevator? Simply described, it's a thin ribbon, about 3 feet wide and 60 thousand miles long, stretching upwards from the surface of the Earth. The lower end is bolted to a heavy anchor (think of an oil drilling platform), and the top is capped with a counterweight.

I think there's a lot of intelligence out there, but that's just my guess. Question is: Are they peaceable or hostile? You could say that the peaceable ones are just going to stay at home and play with their Nintendos, so if you do meet any of them, they might be hostile.

Our retinas and brains have been wired by a hundred million years of evolution to find outlines in a visually complex landscape. This helps us to recognize prey and predators.

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.

Admittedly, it would take industrial-grade chutzpah and a massive dose of malevolence for anyone to bulldoze the spot where Neil Armstrong stepped off the Eagle lander. But even innocent visits could be damaging.

Of course there is still unexplored terrestrial territory, but most of it is waterlogged. Submersed secret places, such as the Challenger Deep, which today lure hi-tech adventurers like Richard Branson and James Cameron, will undoubtedly provide welcome fodder for 'National Geographic.'

Each year, thousands of UFOs are sighted and reported, which is an impressive tally of unidentified aerial phenomena. Surveys show that roughly one-third of the populace believes that at least some of this sky show is due to extraterrestrial spacecraft, here to probe our airspace and, when that proves boring, our bodies.

Lamentably, alien audiences may be frustrated by the switch to digital television. That's because the transmitter power for DTV is fairly evenly spread across the spectrum. The spikiness is gone, and from afar, the attention-grabbing squeals of analog television's carriers have been replaced by DTV's smooth, low hiss.

Are we the only members of the Galaxy that can actually understand what a galaxy is? Could Homo sapiens really be the pinnacle of Creation - the cleverest critters in the cosmos? If we learn the answer is 'no,' that would affect our philosophies forever.

Is E.T. out there? Well, I work at the SETI Institute. That's almost my name. SETI: Search for Extraterrestrial Intelligence. In other words, I look for aliens, and when I tell people that at a cocktail party, they usually look at me with a mildly incredulous look on their face. I try to keep my own face somewhat dispassionate.

A century ago, scientists believed there was only one obvious stomping ground for alien biology in our solar system: Mars. Because it was reminiscent of Earth, Mars was assumed to be chock-a-block with animate beings, and its putative inhabitants got a lot of column inches and screen time.

About the only things that are unique to Earth are our biota and our culture. If aliens ever come here, they'd most likely be either biologists or music fans. Neither one has much reason to antagonize our armed forces.

The strongest signals leaking off our planet are radar transmissions, not television or radio. The most powerful radars, such as the one mounted on the Arecibo telescope (used to study the ionosphere and map asteroids) could be detected with a similarly sized antenna at a distance of nearly 1,000 light-years.

Dating Game' wasn't social commentary, political analysis, Shakespearean-level drama or even blunt-force comedy. It was just the televised equivalent of meeting someone at a bar. But it appealed to our most basic Darwinian instinct: selecting a good mate. You can't go wrong when a show's premise is hard-wired into human DNA.

I got interested in astronomy at the age of 8 because I was looking at an atlas of the planets in my parents' apartment in Arlington, where I grew up. I got a telescope at age 10, which is pretty normal, and by the time I was in eighth grade, I had already seen a lot of cheesy sci-fi films.

Most of the intelligence out there must be artificial intelligence. We keep looking for critters like us living on a planet like ours, where in fact the majority of the intelligence out there is not biological. That would be my argument.

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.

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.

Of course, Sol is a big ball of hot gas, but one that - thanks to its endlessly boiling innards - shakes and vibrates. By studying patterns on the Sun's surface, astronomers can learn much about Sol's internal construction.

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.

Note to academics: Aristarchus' track record of astronomical research would probably have guaranteed him tenure somewhere, if tenure had been invented. His stack of reprints included measuring the distances of the Moon and Sun.

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.

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.