European comet lander Philae 'sniffed' organic molecules containing the carbon element that is the basis of life on Earth before its primary battery ran out and it shut down, German scientists said.
They said it was not yet clear whether they included the complex compounds that make up proteins.
One of the key aims of the mission is to discover whether carbon-based compounds, and through them, ultimately, life, were brought to Earth.
Philae landed on comet 67P/Churyumov-Gerasimenko after a 10-year journey aboard the Rosetta spacecraft on a mission to unlock details about how planets evolved.
It wrapped up its 57-hour mission on the comet's surface on Saturday after radioing back data as its battery ran out.
Comets date back to the formation of our solar system and have preserved ancient organic molecules like a time capsule.
The COSAC gas analysing instrument on Philae was able to 'sniff' the atmosphere and detect the first organic molecules after landing, the DLR German Aerospace Center said.
The lander also drilled into the comet's surface in its hunt for organic molecules, although it is unclear as yet whether Philae managed to deliver a sample to COSAC for analysis.
Also onboard the lander was the MUPUS tool to measure the density and thermal and mechanical properties of the comet's surface. It showed the comet's surface was not as soft as previously believed.
Scientists said MUPUS could be used again if enough sunlight gets through to reload Philae's batteries, which the scientists hope may happen as the comet approaches the sun.