August 1, 2014

The most interesting thing to happen in 4.6 billion years…

Today we are extremely excited that the European Space Agency’s Rosetta spacecraft successfully rendezvoused with Comet 67P/Churyumov–Gerasimenko (A mouthful! — More on that later).

The Comet has been waiting for this day for the entire age of the Solar System, more than 4.6 Billion years, and today it’s being visited by an alien craft from another world – Earth, and we are the aliens that sent it there! At least for the comet, it may be the most interesting thing to happen in 4.6 Billion years.

The Rosetta spacecraft has been enroute to the comet for more than 10 years, a blink in time, but a long time for its Earth-bound operators, and now its true mission can finally begin.

It has been fascinating to see the increasingly more detailed images of Comet 67P/Churyumov–Gerasimenko. It is like nothing scientists have seen to date.


At a distance of some 555 million kilometers, it’s still far enough away from the Sun not to have much cometary activity, with only the faintest of activity visible in long-duration exposures.

So it actually looks a little like… AN ASTEROID!

What is the difference between a comet and asteroid, after all?

Some comets are believed to be as much as 50% water – dirty snowballs so to speak – and what we’re seeing today at 67P/Churyumov–Gerasimenko is what a comet looks like without all that water vapor in the way. Comets generally have very eccentric orbits, and spend most of their time in the outer Solar System, having the innards baked out as they make their passages around the sun. Asteroid orbits are less extreme, so we don’t tend to see their behavior change in time, but it is possible that some asteroids could be extinct comets, waiting for their reserves of ancient water to be discovered.

I’m excited to learn what comet 67P/Churyumov–Gerasimenko has to teach, and there will certainly be surprises. This mission may help us understand more about the makeup and resources on small Solar System bodies. We wish the ESA Rosetta team the best of luck with the mission, and are looking forward to the Philae science lander’s trip to the surface of the comet in November.

So, how about that name? 67P/Churyumov–Gerasimenko – discovered at the Alma-Ata Astrophysical Institute by Klim Ivanovych Churyumov and Svetlana Ivanovna Gerasimenko.

Think you can say it? Check out our team’s attempts below.