The European Space Agency (ESA) just announced that it will release its Rosetta mission lander Philae on Nov. 12. If everything is successful, Philae will land on Comet 67P/Churyumov-Gerasimenko, becoming the first man-made craft to land on a moving comet.
The ESA has dubbed the chosen landing site for Philae "Site J." The spacecraft has journeyed towards the comet ever since it was launched 10 years ago in 2004. The spacecraft is slowing down as it approaches the comet, so it can make the delicate landing. It will be tricky as the comet is moving incredibly quickly. Any small mishap could cause the mission to fail, scrapping 10 years of work.
One challenge will be landing on an area that is not too bumpy or too sloped so that the Philae lander hits an obstacle and falls over. If the lander falls flat, it will have no way to pick itself back up. The ESA team on Earth will also have to choose a landing spot with enough light to keep the craft's solar-charged battery running, but not so much light that it might damage the spacecraft.
To navigate these challenges, the Rosetta craft will slow into a steady orbit when it reaches 20 km above the comet (a distance of a little over 12 miles). The spacecraft will keep slowing and steadily descending until it reaches an orbit 1 km over the surface of the comet. During that time, the team of ESA engineers will be choosing a safe landing spot.
Whether or not the Rosetta mission succeeds, the craft has already achieved a lot of firsts. The Rosetta spacecraft is powered entirely by solar light, making it the first spacecraft to ever come close to Jupiter using only solar power. It is also the first European attempt to pass through the main asteroid belt of our solar system. It has already come closer to a moving comet than any other spacecraft.
If the craft lands successfully, the Philae lander should send back some pretty incredible images of the surface of the comet. It's already taken some amazing pictures of the comet from its close distance.
Rosetta is also carrying a bunch of neat tools, like sensors that can "hear" the comet by sending out sound waves and measuring how they are reflected. The craft is carrying radio tools that can help the scientists visualize the interior of the comet, and a spectrometer to tell the ESA what the chemical makeup of the surface is like.
Any information it sends back to Earth should give scientists exciting new knowledge about comets. We'll look forward to learning more about the duck-shaped comet in the months to come.
