Taylor added, “we’ll be able to monitor the decline in the comet’s activity as we move away from the Sun again, and we’ll have the opportunity to fly closer to the comet to continue collecting more unique data. By comparing detailed ‘before and after’ data, we’ll have a much better understanding of how comets evolve during their lifetimes.”
Comet 67P/Churyumov-Gerasimenko will reach perihelion (closest point to the Sun) on August 13. The nine-month extension will give scientists a more in-depth look at how Comet 67P’s activity rises and falls as it orbits the Sun. The image below was taken earlier this month. You can see how the activity around the comet is increasing as it gets closer to the Sun.
As the comet’s activity begins to die down in the months following August, Rosetta should be able to orbit much closer. Rosetta might even be able to make a final visual confirmation of Philae’s location. Several potential candidates have been imaged from a 20 km orbit, but Rosetta’s mission team hopes to get within 10 km of the comet’s surface.
What Rosetta will do with its extra nine months
Mission planners will take advantage of this extra mission time to try some riskier experiments. One of these includes flying across the night-side of the comet to see how plasma, dust and gas interacts on that side of the comet.
They will also attempt to maneuver Rosetta close enough to the comet to collect dust samples ejected from around its nucleus.
These additional observations will also help scientists using telescopes on Earth to study Comet 67P. Right now, the comet’s close proximity to the sun has most ground-based observations sidelined.
So, what happens in September 2016? Rosetta’s mission will end in the same fashion Philae’s began. Scientists want to land Rosetta on the comet’s surface.
Patrick Martin, Rosetta’s Mission Manager, talked about the potential for a Rosetta comet landing:
“But there is still a lot to do to confirm that this end-of-mission scenario is possible. We’ll first have to see what the status of the spacecraft is after perihelion and how well it is performing close to the comet, and later we will have to try and determine where on the surface we can have a touchdown.”
If a touchdown does happen, Rosetta will spend its final moments studying Comet 67P in unprecedented detail.
The Latest on Philae
Philae woke up over the weekend and sent a pair of two-minute radio transmissions. The lander is in good condition, but Philae will have to wait a little bit longer before it can start working again.
ESA officials want to get Rosetta into a better orbit so it can have longer and more predictable radio contact with Philae. Once that happens, the little lander will fire back up its science instruments.
Image credits: ESA. Top image is an artist concept of Rosetta and Comet 67P