Earthlings are already exploring the possibilities of living on the moon, but what if we could survive on alien moons? We might.
Astronomers and astrobiologists were all about searching for life as we know it, as Seeker observed—emphasis on as we know it. Planets in that holy grail “Goldilocks zone”, are just far enough from the sun not to get scorched but not distant enough to freeze. Then Cassini (RIP) beamed back data that started to change their minds. When it sent its probe Huygens to the surface of Saturn’s moon Titan, to say what its robotic eye saw was unexpected is an understatement.
Huygens was able to navigate through the almost impenetrable haze of Titan’s atmosphere and touch down on its surface, which is the only extraterrestrial surface we know of that has lakes and seas (subsurface oceans may be more abundant in space). Moonquakes, Marsquakes and killer radiation aren’t an issue, and you could actually stand on it with just an oxygen tank and a space suit warm enough for -290 degrees Fahrenheit. You might even need an umbrella. Rain falls and thunderstorms strike, which may sound familiar, but what falls out of the skies of Titan is not what Earth creatures are used to.
“That liquid is not water,” NASA JPL technologist Morgan Cable told Seeker. “It’s methane and ethane, liquid hydrocarbons that are forming just like on Earth, like how we have clouds and rain event. Same thing happens on Titan, but it’s with an entirely different set of molecules.”
Human existence on Titan could still be potentially easier than putting up with the hostile environments of Mars or our own moon. Life could theoretically stay alive because of its stable atmosphere and unique composition, which includes the biochemically significant molecules propylene and acrylonitrile. All that methane also means free rocket fuel. Titan could be the way station of the future, where starships make a pit stop to refuel before taking off for a new home planet.
Titan isn’t the only Saturnian moon making waves with its liquid oceans. Beneath the icy crust of Enceladus is what scientists believe to be a vast ocean world that may have spawned life as we know it or even as we don’t know it. In 2015, Cassini dove into in a vaporous plume gushing from the surface and detected hydrogen.
“There was a significant amount of molecular hydrogen,” said Hunter Waite, INMS Instrument Team Lead of the Southwest Research Institute, in a NASA video interview. “The existence of molecular hydrogen, at least within the Earth’s ocean system, is a food source, it’s candy for microbes. They eat the hydrogen, they turn it into methane.”
Does this mean Enceladus and Jovian moon Europa, which also erupts in water vapor, are crawling with microbial aliens? Not necessarily. Even though we have no evidence of alien sea creatures, you still can’t ignore how eerily similar these plumes are to what spews from the hydrothermal vents at the bottom of the ocean, which attract all sorts of strange and fascinating life-forms.
“It’s not demonstration of finding life,” Waite said, “But it shows the potential for the existence of life.”
That may be all we need to become an interplanetary species.