Earth was assumed until only recently to be the only planet in the solar system with liquid water. But space scientists now understand this is not the case, following decades of missions by US space agency NASA. And NASA is increasingly confident these watery worlds are the best place to look for alien life.
NASA has accordingly now launched its Ocean Worlds Exploration Program, in an audacious attempt to track down aquatic alien life.
There could be some crazy form of methane-based life right there on Titan’s surface
Dr Amanda Hendrix, co-lead of the NASA Roadmaps to Oceans World Group, exclusively explains how the Ocean World’s Program represents one of the best chances of encountering alien life.
She said: “Ocean worlds may represent the best possibility, in our solar system, of finding life.
“We need to understand whether these oceans are habitable and if so, whether these oceans actually host life.”
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And Dr Hendrix believes Saturn’s moon Titan represents a fascinating prospect for finding alien life.
The NASA scientist said: “Titan is a very unique ocean world because it has both an ocean at the subsurface and it also has liquid hydrocarbon lakes on the surface.
“So there could be some crazy form of methane-based life right there on Titan’s surface.”
However any life found in these oceans would certainly be simple, she adds.
“There would not be aliens with green heads swimming around in there.
“I think it is possible there could be some simple life forms in some of these ocean worlds in our outer solar system.”
The NASA Ocean Worlds Exploration Program represents a significant strategic shift in its attempts to find alien life, explains Dr Hendrix.
She said: “We used to think Mars was our best opportunity of looking for life, and now we know that Mars is not currently habitable.
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“Mars now appears to be our best chance of looking for past evidence of life.”
And Titan is far from alone in being a potentially habitable body in the star system, with Enceladus and Europa also high on the list of place to explore.
Enceladus is the sixth-largest moon of Saturn, while Europa is the smallest of the four Galilean moons orbiting Jupiter.
“The NASA Dragonfly Concept is a New Frontiers concept and the selection is between that and its competitor, the NASA Comet Sample-Return mission.
“I believe the decision about which will run will be made later this year.
“One of these missions will happen sooner rather than later, which is very exciting.
There are also proposed missions to visit Enceladus and that would take the form of a flyby mission.
“It turns out that Europa is a very challenging environment because the radiation environment of Jupiter is very intense, which makes it very difficult and expensive to operate a mission there.
“Enceladus, on the other hand, is spewing its ocean material right out at us into space, so it presents a much easier opportunity to study that material.”
NASA: The Dragonfly mission could explore Titan
Dr Hendrix explains how Titan has already been explored once before.
She said: “The Huygens Probe that was part of the Cassini-Huygens mission, landed on Titan’s surface.
“The probe was not designed to investigate the habitability of the surface, or to look for life, but it did land on the surface.
“But there is a mission concept, currently under investigation at NASA, the Dragonfly mission, and that would both land on Titan’s surface and fly around in its atmosphere, using a quadcopter-type design.
“This would tell us a lot about the habitability of Titan’s surface.”