With no meal for 86 million years, and barely enough oxygen to sustain metabolism, can a single-celled organism really be considered alive? Yes, but only just, according to a new study. A microbial community buried under the ocean floor since the mid-Jurassic era is still hanging on. Their tenacity could pose some interesting questions for the hunt for alien life.
As Earth humans begin to seriously consider sending missions to icy worlds like Europa and Enceladus, one of the necessary concerns has to be protection of the environment where such a mission would land. It would be a shame to arrive on a fascinating alien world only to immediately seed it with Earth microbes, carelessly infecting the local ecosystem, ruining the unique scientific opportunity and possibly incurring the wrath of the local alien ruler.
Aside from ancient Mars, the moons of Saturn might be one of the best places to look for life outside this planet. The methane lakes of Titan are promising places, but so are the spewing plumes of ice on Enceladus — and the latter would be an easy one to check, as it turns out.
These days, every exoplanet discovery is still rich with excitement, as astronomers scrutinize each distant world and consider its possible characteristics. But this could get tedious pretty soon, as the number of confirmed exoplanets climbs into the thousands. When that happens, astronomers and especially astrobiologists will have to start sifting planets according to their interestingness. A new paper to be published next month describes a new two-step ranking system to make this process easier. We spoke to astrobiologist Dirk Schulze-Makuch to get some details.