Stay on target
Yesterday, NASA held a press conference today announcing that Enceladus may harbor life. That’s right; we may have alien life right here in our solar system.
Scientists have confirmed that there’s plenty of chemical energy within the moon’s underground lakes to support life. Molecular hydrogen, for example, is evidence of hydrothermal vents, and it, alongside water, and a smattering of other minerals and compounds are all necessary for life. What’s more, every time we’ve found this cocktail of chemicals here on earth, we’ve also found life. It’s likely that if Enceladus has life, we’ll find it near the ocean floor where thermal vents provide an excellent source of energy and nutrients for life. This discovery officially makes Enceladus the most likely candidate for life outside of Earth we’ve yet found.
The results were published today in the journal Science and expounded with a press conference at Washington’s James Webb Auditorium. To be clear — we haven’t found life yet, but we’re looking at a very similar set of materials to what we’d find on Earth’s own ocean floor. And while it might be dark and cold in the depths, it’s also home to vital ecosystems and thousands of species across the world.
Enceladus is, notably, not Earth and there will be some big challenges to any search for life. For one, the ocean is a staggering 37 miles deep — a long way to go for a remote-controlled submersible. Enceladus also has an elliptical orbit around Saturn, meaning tidal forces keep the core and the ocean above it uncharacteristically warm. Parts of the massive ocean may be close to water’s boiling point, and there’s no telling how that might affect potential organisms.
The announcement is also the culmination of more than a decade of study with the Casini probe as well as the Hubble Space Telescope. In 2015, NASA used Casini to collect samples from massive plumes of water vapor erupting from the icy surface. Since then, the analysis suggests that there’s a litany of organic molecules as well as virtually all of the major ingredients for life.
We still can’t say for sure that life is on Enceladus, but it wouldn’t be an exaggeration to say that this is the closest humanity has yet come to finding life on another world. Molecular hydrogen, for example, is generally unstable and quickly binds to other chemicals. It’s also an important ingredient for life, and without a source to replenish it, the substance doesn’t stick around for long. Since Casini found loads of hydrogen, we know that something has to be making it. And that dramatically increases the chances that Enceladus has active hydrothermal vents, which could be feeding primitive microbes.
It’s hard to overstate the significance of the discovery, but you can be sure that NASA, the European Space Agency, and others are probably eyeing Saturn’s medium-sized oceanic moon a bit more closely for future missions.