Rosetta’s Last Hurrah at Comet 67P

Rosetta Becomes One With Comet 67P

rosetta comet landing

One of the last images taken by the Rosetta orbiter on its way to the surface of Comet 67P/Churyumov-Gerasimenko. Courtesy ESA.

On September 29th, 2016,  ESA’s Rosetta orbiter made a guided “soft” crash landing onto the nucleus of Comet 67P. It’s now forever a part of the comet. It will be until the nucleus breaks up sometime in the future as it rounds the Sun. By all accounts (and you can read detailed reports on the mission at the Rosetta site), the mission was a rousing success. It was the first one to do a long-term orbit of a comet and send back stunning high-res images of the nucleus. That alone cemented its place in history for me. Back in grad school I studied comets and always wondered what it would be like to land on a nucleus. With Rosetta, that wonder was satisfied.

Exploring Small Worlds

Rosetta isn’t the first and won’t be the last to study such fascinating world. I feel pretty confident that there will be more probes to asteroids and comets. These objects are the building blocks of the solar system. These families of small bodies were the first to clump together to form the planets. That means they hold the key to understanding what materials and conditions were like as the solar system formed some 4.6 billion years ago. They may even hold clues to primordial materials that existed even before the Sun and planets began their birth process. For those reasons and many others, I hope we do continue to study these worldlets.

What’s Next For the Rosetta Mission?

The scientists on the Rosetta mission literally have many years worth of study ahead of them. The spacecraft sent back tantalizing data about the ices and dust in the comet, its lack of magnetic field, and other characteristics. I imagine that many post-docs and PhD students will contribute their brainpower to understanding the data and communicating what they find to the rest of us. So, far from being over, the Rosetta spacecraft’s greatest legacy is just beginning: analyzing and comprehending what the spacecraft “saw” for the rest of us.

Lose Your Craft in a Crack and You Can’t Get it Back

That’s a Philae !

I know. I couldn’t resist. As soon as I saw the headlines about the lost Philae craft and how the Rosetta mission team found it lost in a crack, I had that song running through my mind.  But, behind the levity is a great story about loss and redemption, space-exploration style.

As you may recall, the Rosetta spacecraft studying Comet 67P/Churyumov-Gerasimenko sent a tiny little lander called Philae down to the surface of the comet’s nucleus. It landed on November 12, 2014, but it was a bouncy landing that placed the little robot in the shadow of an icy cliff.  Due to its peculiar orientation, the batteries couldn’t recharge (very little sunlight was hitting the solar panels). That meant the lander only worked for a short time before falling to sleep.  It actually did wake up again in June 2015, but that didn’t last long either.  Philae has been in hibernation ever since, and the mission scientists have spent time trying to locate its exact landing spot on the comet.

Philae  Craft Found!

Philae craft found on comet

The Philae lander identified via narrow-angle camera image taken by the Rosetta spacecraft on Sept. 2, 2016. Earlier images provided for scale and orientation. ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; context: ESA/Rosetta/ NavCam – CC BY-SA IGO 3.0

On September 2, Rosetta passed within 2.7 kilometers of the comet’s nucleus and snapped images of the region where Philae landed.  There, in the narrow-angle images, the mission team finally found what they were looking for: evidence of Philae’s location and orientation. It was an amazing finding, considering that the spacecraft is moving with respect to the comet, which is moving with respect to the Sun, and rotating, too. It’s really like finding a needle in an icy haystack.

When you stop to think about the fact that Rosetta is due to encounter the surface of the comet during a final “one-way” mission  in about a month, the discovery of the final resting place of the Philae craft is all the more amazing. You can read more about the logistics of the search on ESA’s Rosetta site.

Comet Exploration Done Right

The Rosetta mission is an astounding success, with its almost three-year exploration of a cometary nucleus. Back in grad school, I studied comets, and always wondered about the chunks of dirty ice at their hearts. Rosetta has shown us that these are eerie-looking worlds with familiar-looking features. Canyons, mountains, sprays of ice and dust, piles of chunky ice that look like rocks, and smooth plains all tell a tale of the comet’s origins and evolution. Philae’s short life of data-taking told a tale, too, lending a lot of new data to our knowledge of comets. So, even if it did get its craft in a crack and can’t get it back, Rosetta has given us a great gift in our search for an understanding of all the objects in our solar system.