We can no better imagine what will be happening on the moon 500 years from now than Columbus could imagine contemporary Manhattan. Except to say that it will be a place familiar to billions of people.
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.
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?
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?
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.
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.
'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?
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.
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.
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.
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.
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.
We're not just any star stuff, most of which is humdrum hydrogen and listless helium. Our bodies include fancier ingredients like carbon, oxygen, nitrogen, phosphorous, and a few other herbs and spices.
In general, when moviemakers talk to scientists, they usually see them as a resource to solve particular technical problems or script problems for them. So, something like: what sort of weaponry would aliens be able to wield?
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.
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.
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.
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.
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.
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.
'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.
I actually think the chances that we'll find E.T. are pretty good.
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 planets and moons of our solar system are blatantly visible because they reflect sunlight. Without the nearby Sun, these planets would be cryptic and dark on the sky.
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.
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.
If you could drive straight down, into a tunnel bored through the crust of the planet, you'd hit this molten mess in about an hour. It's called the asthenosphere - a sluggish sea, several hundred miles thick, on which floats the Earth's cool epidermis - the so-called tectonic plates.
We're interested in things that have big teeth, and you can see the evolutionary value of that, and you can also see the practical consequences by watching 'Animal Planet.' You notice they make very few programs about gerbils. It's mostly about things that have big teeth.
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.
If this is the only planet on which not only life, but intelligent life, has arisen, that would be very unusual.
The idea of close encounters of the zero'th kind - which is to say, not a close encounter at all, but simply uncovering evidence that someone's out there - dates back to the Victorian era.
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.
Star Trek's genial premise is that the cosmos is flush with intelligent species, and our descendants will interact with them face-to-face, thanks to warp drive and some winsome space cadets.
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.
We can never prove that we're alone in the universe. But the Allen Telescope Array could prove that we're not.
We'll be 'outsourcing' our creativity and our thought processes to manufactured components that could be inconspicuously implanted beneath our coiffeurs. Welcome to the Borg. You might not be entirely comfortable with such cybernetic enhancements, but all the smart money says it's going to happen.
