Scientists believe that the moon’s ocean may have formed after water-rich minerals released their water due to heating caused by the radioactive decay of the satellite’s core. Due to its gravitational interactions with the gas giant Jupiter and other moons, the water is kept warm.
But not all water means life. Other important building blocks are needed, and researchers believe that to be the case.
“This ocean could be quite habitable”
Billions of years ago, the ocean would have been slightly acidic, but with concentrations of carbon dioxide, calcium, and sulfate too high for life as we know it.
“Our simulations, coupled with data from the Hubble space telescope, showing chloride on the surface of Europa, suggest that the water has probably become rich in chloride,” said Mohit Melwani Daswani, geochemist and planetary scientist at Jet Propulsion Laboratory at NASA, which presented the recent discoveries at the Goldschmidt virtual conference this week.
“In other words, its composition was more like oceans on Earth. We think this ocean [now] could be quite habitable for life. ”
Water and minerals are not the only elements necessary for life. Life needs energy.
“It is unlikely that any possible form of life in the Europa ocean will use sunlight as a source of energy, as Europa is really far enough from the sun, and the ocean would be in total darkness under a shell of very thick ice, ”said Melwani Daswani. “So we have to think of other sources of energy. ”
Life on Earth exists around hydrothermal vents, openings at the bottom of the ocean that emit dissolved minerals, and there is strong evidence that they can also exist in the subglacial ocean of Europe. It could be used as an energy source for all potential life.
Melwani Daswani is careful.
“We don’t even know if life as we know it would be happy there or if the energy available for it during life would be sufficient,” he added.
Mission to Europa
Gordon Osinski, a professor in the Department of Earth Sciences at Western University in London, Ontario, who was not involved in the study, said that this new research is another reason why the missions to the moons like Europa or Enceladus are so intriguing.
“I think the key to remember here is that these ocean worlds present the best chances for today’s livable environments,” he said. “So life living on these planets right now. All the key ingredients are there. ”
NASA has an ongoing mission to visit the moon: the Europa Clipper.
The mission – the first mission dedicated to a moon other than ours – will not look for signs of life, because it will only orbit, but it will seek increasing evidence of potential habitability by studying its geology, its frozen shell and its composition. .
Osinski said it would be ideal for a future sample return mission, where a spacecraft could even fly through and collect plumes of water vapor that were seen blown into space by Europa and Enceladus at through cracks in the ice.
“Because then we will know,” he said. “We will have the unequivocal determination of the existence or not of life. “