Thursday, October 15, 2015

Aliens? No, Seriously!

One of the biggest questions in astronomy relates to the Fermi Paradox, which can best be summed up as "where are all the aliens?" The argument goes as follows: if the universe really is infinite and so much older than the solar system, how is it that we see no evidence of really advanced alien civilizations anywhere? In theory, super-advanced aliens would have the ability to create structures so massive that our best telescopes might be able to detect them. But so far that hasn't happened.

That is, maybe, until now. Scientists working with the Kepler Space Telescope have identified a star about 1500 light years away that appears to have many large objects orbiting it that are more tightly clustered than anything they've ever seen. If the star were young the objects could be part of an accretion disk, but the star is old enough that any such disk should have coalesced into planets long ago. It's also possible that the objects are comets, though that in itself would be extremely unusual.

It's the final possibility that has pushed this story into the news. The objects could be mega-structures built by a race of space-faring aliens. That is, aliens with mature space travel technology over a thousand years ago, which is how long it takes the light from this star to reach us. If so, that answers the Fermi Paradox. The aliens are right over there.

The snappily named KIC 8462852 star lies just above the Milky Way between the constellations Cygnus and Lyra. It first attracted the attention of astronomers in 2009 when the Kepler Space Telescope identified it as a candidate for having orbiting Earth-like planets. But KIC 8462852 was emitting a stranger light pattern than any of the other stars in Kepler’s search for habitable planets.

Tabetha Boyajian, a postdoc at Yale told The Atlantic: “We’d never seen anything like this star. It was really weird. We thought it might be bad data or movement on the spacecraft, but everything checked out.” In 2011 the star was flagged up again by several members of Kepler’s “Planet Hunters” team – a group of ‘citizen scientists’ tasked with analysing the data from the 150,000 stars Kepler was watching. The analysts tagged the star as “interesting “ and “bizarre” because it was surrounded by a mess of matter in tight formation.

This was consistent with the mass of debris that surrounds a young star just as it did with our sun before the planets formed. However this star wasn’t young and the debris must have been deposited around it fairly recently or it would have been clumped together by gravity – or swallowed by the star itself.

Boyajian, who oversees the “Planet Hunters” project, recently published a paper looking at all the possible natural explanations for the objects and found all of them wanting except one – that another star had pulled a string of comets close to KIC 8462852. But even this would involve an incredibly improbable coincidence.

I expect this discovery is probably more likely to go the way of pulsars, which astronomers thought might represent signals from an alien civilization back when they were first detected. Now we know that they are just unusual astronomical objects that happen to emit regular-looking pulses of energy. Still, until an alien civilization can be ruled out, we must accept the possibility that this might be one. And, if it is, they would be far more technologically advanced than we are.

So why haven't we met them, if they're theoretically advanced enough to build stardrives and so forth? The simple answer is that they probably have no idea we even exist. It takes 1500 years for light to travel from Earth to KIC 8462852, and 1500 years ago the Earth wasn't emitting any sort of signal that would indicate it to be inhabited. We've only been doing that for the last hundred years or so. So unless one of their spacecraft passed with a hundred light years of Earth with monitoring instruments turned on, they'd have no idea.

So if these really are aliens, I wonder if they practice magick...

Technorati Digg This Stumble Stumble

No comments: