A German-built instrument installed on the Philae lander was able to sniff and detect organic compounds in the comet's atmosphere shortly after the spacecraft touched down. The compounds were likely kicked up into the air along with dust particles as Philae bounced its way to an abrupt but historic stop on the surface of Comet 67P/Churyumov-Gerasimenko.
Organic compounds are the building blocks of life. They are also essentially any chemical compound that contains carbon, and some are rarer and more vital to life than others. Methane (one atom of carbon and four atoms of hydrogen), for example, is ubiquitous in the universe, but complex molecules like amino acids are harder to come by. Finding evidence of such on a comet would further confirm astronomers' long held suspicions that the secret ingredients for life (including water) were delivered via comet.
Unfortunately, Philae's Cosac instrument hasn't been able to determine which type of organic compounds are present. And scientists may never find out, as Philae is currently unresponsive -- its solar-powered batteries unable to recharge with the lander stuck in the shadow of a crater.
Philae's drilling attempts weren't able to return any soil samples to its oven, but the efforts did take a reading on the comet's density. Results suggest the comet is a water-ice mixture covered in several inches of dust.
Philae's controllers hope that as Comet 67P/Churyumov-Gerasimenko makes its way closer to the sun in the coming months, Philae's solar panel may catch some rays and recharge -- allowing ESA to resume their scientific efforts.
"Given the fact that there is a factor of six, seven, eight in solar illumination and the last action we took was to rotate the body of Philae around to get the bigger solar panel in, I think it's perfectly reasonable to think it may well happen," Mark McCaughrean, a senior science adviser to ESA, told BBC News.
"By being in the shadow of the cliff, it might even help us, that we might not get so hot, even at full solar illumination. But if you don't get so hot that you don't overheat, have you got enough solar power to charge the system."