Scientists found signs of life in samples dating back 830 million years. And it’s possible some of them are even still alive. They extracted samples from a mile-deep core sample in Western Australia, an area that used to be a salty sea. The research serves as a good analog for evidence of life in the lakebeds of Mars and is partially funded by NASA.
The researchers found both prokaryotes (bacteria) and eukaryotes (algae, plants) inside halite crystals. Halite is your basic salt, also known as table salt, rock salt, NaCl, or sodium chloride. When salt crystals form, they can trap small amounts of air and water inside. Scientists use them to study the conditions of the ancient oceans and atmosphere. Sometimes the crystals also contain tiny life trapped inside.
In order to study that life, scientists usually crush or dissolve the salt crystals. These techniques can contaminate the sample and also means there’s no second chance to examine them. This team went looking for a better way. The peer-reviewed journal Geology published the results, which we found in Science Alert.
The scientists determined that the evidence of life trapped inside could be studied without destroying the sample. If NASA follows this procedure with samples returning from Mars, they can be studied over time as techniques advance. The team used various forms of light, including ultraviolet and cross-polarized light, to examine the halite. Some fluoresce blue, which is similar to live specimens. Others were white, gold, or did not fluoresce at all, which could mean they were dead and decayed to various degrees.
The life inside these crystals probably belonged to extremophiles, meaning it can survive under extreme conditions like heat, cold, and saltiness. Many extremophiles effectively hibernate when conditions are too unfavorable, but they can reanimate later. In previous work, scientists brought 100-million-year-old microbes back to life. It is possible these 830-million-year-old samples could be revived as well. Especially those “live” cells trapped in with decaying cells, which they can feed off of.
Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.