Five hundred million kilometers from Earth a comet is streaking toward the Sun. No worries. Not a threat to us.
Earthlings, being curious people, thought we’d send a mission to this comet to find out what it’s made of. Theoretically, comets are a direct link to the universe just after the Big Bang.
Catching a comet is no easy feat. Its speed is greatly affected by proximity to the Sun–so, constantly changing. Our comet is doing around 38,000 mph today. The instant we arrive we need to be doing exactly the same speed as the comet. Seriously, at that instant exactly.
To get to Comet 67P/CG “Rosetta” will travel over 6,500,000,000 kilometers. That’s on purpose. By swinging through the Earth’s gravitational field a few times engineers were able to stretch precious fuel.
Rosetta is now orbiting Comet 67P/CG at around 10 miles, a little higher than commercial jets fly.
Getting to the comet wasn’t enough. How about we land on it? It’s the 21st Century equivalent of climbing from your horse onto an out-of-control stagecoach!
The comet is weirdly shaped, moving and spinning. It’s sublimating ice, so we see gas jets spewing out. More than likely the comet’s path from moment-to-moment is irregular. There is nearly zero gravity to prevent a landing spacecraft from just bouncing right off.
November 12 a small instrument package will be jettisoned from Rosetta. Rockets pushing toward the surface will hold it in place as harpoons try to get a grip. “Philae” will set up shop for scientific experiments and transmit results to Rosetta which will relay it back to Earth.
I have no doubt this will work.
What NASA and the European Space Agency have done here is nothing short of incredible. It’s much more than most people imagine can be done today. I wish this kind of engineering heft was also available for some of the Earth’s seemingly insurmountable problems.