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. Seth Shostak continueearthlingephemeral share on social
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. Seth Shostak backclosedate Change image and share on social
Any society that could come here could pick up the lights from New York. What should we do about that? Should we darken New York from now until the last human expires? Would we want to turn off all the radars at JFK airport? Seth Shostak airportdarkenexpire share on social
This plucky NASA telescope is able to find planets en masse. If you compare planet hunting to prospecting for gold, then Kepler is equivalent to trading in your trusty pan for a diesel-powered sluice box. Seth Shostak boxcomparediesel share on social
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 alienastronomerbillion share on social
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. Seth Shostak alexanderalienbase share on social
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. Seth Shostak 000armageddonasteroid share on social
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. Seth Shostak bellowbleatbulk share on social
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. Seth Shostak airattentioncheap share on social
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. Seth Shostak agoasteroidball share on social