Philae experiment grabbed precious data before lander lost power
The first touchdown on 12 November, when the probe bounced, created a cloud of dust which an experiment called Ptolemy was able to sample. Sen spoke about the findings to its Principal Investigator, Professor Ian Wright of the UK's Open University.
Ptolemy is an evolved gas analyser aboard Philae, which obtains accurate measurements of light elements. Professor Wright explained that Ptolemy was pre-programmed to sample its environment shortly after landing, providing a feast of data.
OSIRIS spots Philae drifting across the comet. Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Philae eventually came to rest in the shade meaning it was unable to recharge its solar-powered batteries. The Ptolemy team had only a few hours to rethink and upload fresh commands to the instrument to collect as much data as they could.
With time running out, Rosetta mission planners granted the UK team Philae's last ounce of strength to operate Ptolemy's oven, to heat up the samples collected inside the instrument to 200°C and analyse the gases that came off.
The team detected what might be complex carbon compounds suggesting that comets like 67P may have brought the building blocks of life to Earth. Carbon-containing "organics" have also been detected by a German instrument called Cosac.
Professor Wright told Sen: "Under the circumstances we are feeling pretty good about what we have got (so far!). We have been able to make measurements of organic compounds at the surface of a comet—the first time this has ever been done.
"Not only that, but at the end of our experiments, the instrument powered down properly and is clearly in good shape to make more measurements should we get the chance later in the mission. We're keeping our fingers crossed!"
Professor Wright was referring to the hope that, as the comet continues to move closer to the Sun, Philae may receive enough sunlight to recharge its batteries and come back to life.
Philae's instruments. Image credit: ESA/ATG medialab
The professor said the team were able to state with absolute certainty that they had seen a very large signal of what are basically organic (carbon) compounds.
He added: "There is a rich signal there. It is not simple. It is not like there are two compounds; there are clearly a lot of things there—a lot of peaks. Sometimes a complicated compound can give a lot of peaks."
Professor Wright told Sen: "We have attempted to make isotopic measurements, but the data are complicated and will take time to evaluate." (Isotopes are different forms of the same element).
"On the basis of the data we have we will be able to say something about the chemical composition of the surface—and this can then be compared with what has been, and what will continue to be, detected by the orbiter, Rosetta."