At a conference on Tuesday, April 7 NASA chief scientist Ellen Stofan expressed optimism about the ongoing search for life as we know it elsewhere in the universe.
“I think we’re going to have strong indications of life beyond Earth within a decade, and I think we’re going to have definitive evidence within 20 to 30 years. We know where to look. We know how to look. In most cases we have the technology, and we’re on a path to implementing it. And so I think we’re definitely on the road,” said Stofan according to Space.com.
The optimism seems to be based, largely, on the realization that water is one of the most abundant substances in the solar system and, probably, the rest of the universe. A page posted by NASA the same day as the news conference discusses many of the recent discoveries of water, and even warm-water oceans within our solar system and beyond.
“NASA science activities have provided a wave of amazing findings related to water in recent years that inspire us to continue investigating our origins and the fascinating possibilities for other worlds, and life, in the universe. In our lifetime, we may very well finally answer whether we are alone in the solar system and beyond,” said Stofan.
Everywhere that we find water, on Earth, we also find life. This has proved true regardless of other environmental conditions. Life, in one form or another, has been found in the furthest depths of the oceans, in trenches near boiling hot lava flows and deep beneath the arctic ice.
In space, scientists have found water almost every place we’ve looked. There is water, in some form on just about every object in the solar system including comets, meteors, asteroids, planets and moons.
Even apparently desolate places like Mercury and our Moon have isolated pockets of water. The gas giants, whose atmospheres would be toxic to us all contain large amounts of water and some bodies contain large amounts of liquid water where researchers hope they might find some kind of life.
The theory or, at least, hope is that somewhere on one of these bodies life might exist in some form.
It is a bit like making a dish you particularly enjoy without a recipe. Scientists hope that if you mix the same ingredients together in enough pots that eventually you might get the same outcome. Finding life, even bacterial life, in any of these places would be incredibly important because to date we only know of life on Earth. If, however, life exists in at least two places then there is a very good change that it exists in a great many places among the billions of stars and planets in our galaxy.
In our solar system there are 10 bodies, including the Earth, which appear to have oceans. This does not include Mars which appears to have once have had, and lost, an ocean but which could still sustain life in some form beneath the surface or could have had life once.
Beyond Earth, the closest body thought to have large amounts of liquid water is the dwarf planet Ceres in the asteroid belt. The Dawn spacecraft is currently orbiting Ceres and more will be known soon but researchers believe that it is 25 percent water and that some of that water could exist in a liquid state.
Jupiters moons Europa, Ganymede and Callisto are all thought to have some amount of liquid water. Europa is also thought to experience tidal heating compliments of its parent planet. Ganymede has its own magnetic field and could have several layers of ice and water beneath its surface.
Like Jupiter, Saturn has three moons which appear to have liquid water. Enceladus, Titan and Mimas all appear to have very deep oceans. All of them would, again, be buried beneath layers of ice but without a protective atmosphere or magnetic field those layers of ice could prove to be a useful shield against cosmic radiation for anything living in the water.
Finally there is Neptune’s moon Triton. Although it is very cold there appears to be a great deal of activity, including possible volcanic activity, beneath the surface.
Pluto, where the New Horizons spacecraft will arrive in June could have a subsurface ocean as well. It is hard to imagine anything living on the cold, distant dwarf planet but we currently only have one example of an inhabited planet so its hard to say what is possible.
Outside our solar system there is little reason to believe that things are much different. Water appears to be everywhere we look, from dust clouds that have yet to form planets and stars to water words covered by warm oceans. However, those may take a bit longer to explore in depth.
