Thursday, March 18, 2010

We'll All be Roon'd, said Hanrahan

A rogue star flies head-on toward our solar system, ineluctably, at 14 kilometres a second...

Gliese 710, perhaps 60% the mass of our Sun, will come within 0.2 light-years of us in, oh, only about 1.4 million years time (it's currently 63 light-years away, but getting closer every day).  Coming so near, it will disturb the Oort Cloud, the far-flung shell of comets orbiting about our solar system – but it seems the sky will not overnight fill with the tails of dangerously veering celestial bodies portending terrifying impact and doom; rather, there will be a rise in what astronomers meekly call the "cratering rate" for about a million years.

Of old, it was said that comets appeared when the fog of man's sins, ascending as a miasma from our miserable world, was ignited by the blazing wrath of the Almighty: but as a wit observed, if this were true, the sky would be always full of comets!

Whatever of speculation old and new, there does remain, however, a 1 in 10,000 chance that Gliese 710 will run within 1000 AU of our Sun, which would disturb the orbits of Kuiper Belt objects such as Pluto and its dwarf planet brethren, even affecting the orbit of Neptune.

For those who enjoy the vicarious thrill of imagining disaster (literally the curse of "an evil star"), may I recommend a somewhat ghoulish pastime available at "The Astronomy Workshop", demonstrating what would happen if a passing star disturbed all the planets' orbits - oh how dreadful is the onrush of a rogue star to the people of earth!

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