Stalking a comet

by Credit Union Geek

by: Joe Winn, Credit Union Geek

Update: This post relates to the comet flyby in October of Siding Spring past Mars.  Earlier today, the Philae lander flying on Rosetta (a European Space Agency mission) made a soft landing on comet 67P/Churyumov-Gerasimenko.  A first for humans, we look forward to the science data and imagery Philae will return.

Call it an interstellar flash mob.

A once-in-a-lifetime opportunity arose in October for astronomers. In 2013, a comet was seen hurtling towards the Sun. Not too surprising, as many do just that in the course of their orbits. Except this one was different. We hadn’t seen it before. And it came from far away. Scratch that, very, very far away.

Comets we see come from the Kupier Belt. Imagine a mish-mash of rocks and debris in the general area of Pluto. But not this one, now called Comet Siding Spring, after the observatory from which it was discovered. Siding Spring came from the Oort Cloud, a favorite name from my childhood (thank you Dutch astronomer Jan Oort), but also a special region of space. If you think the Voyager spacecrafts have gone far, picture this: The Oort Cloud is a thousand times further away than them, and they’ve been flying for over 35 years. The cloud has material from the birth of our solar system, and Siding Spring has not come close to the sun…ever.

So this comet is on a long journey.

There’s more! Projections of Siding Spring’s path took it into, no, past Mars…so close that it would interact with the upper Martian atmosphere. It’s like a ball whizzing through the hairs on your neck.

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