Aliens!

Could humanity be close to finding alien life forms?

According to NASA Chief Scientist Ellen Stofan, yes. She believes that we'll have signs of alien life in just the next decade, with confirmation coming in approximately the next twenty years. 

Speaking recently at a NASA TV panel discussion, she said that "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."

Exciting stuff, but the first discovery of alien life will probably not be in the form of the iconic little green man, but rather some kind of bacteria or a species of pond life. Nonetheless, finding alien life would still be an incredible discovery. 

As for where to look, it is thought that salt water oceans exist beneath the icy outer layers of the moons of Jupiter, Europa and Ganymede, as well as Saturn's moon Enceladus. The water doesn’t freeze due to the intense gravitational forces that the huge planets produce, which causes the moons to be warped, heating them up. This effect is in part the reason that Enceladus is thought to have volcanic activity on its ocean floor, heating the water up to around 93C, which is similar to the conditions that may have been present in the early oceans on Earth.

Another possibility for the presence of alien life is Mars. It is known that our closest neighbour did have water on its surface in the past, and photographic evidence indicates that water may still be present under the surface, as it occasionally makes it to the surface to form temporary rivers.

NASA's Curiosity Rover has also recently discovered "carbon containing organic molecules" on the red planet, which are the basic building blocks for life – we are made out of them, just like all life on Earth.

The next Mars rover, which is scheduled to launch in 2020, will search for signs of past life, before manned landings on the planet in the 2030’s, which would be another huge stride forward for humanity. Scientists believe that men on Mars would be key to the search for life, because even with all of the rovers’ incredible photographic technology, discovering fossils by remote control is a difficult task, partially because the Rovers can’t turn over rocks.

Speaking to the panel, Stofan said that “I go out and break open rocks and look for fossils, those are hard to find. So I have a bias that it's eventually going to take humans on the surface of Mars - field geologists, astrobiologists, chemists - actually out there looking for that good evidence of life that we can bring back to Earth for all the scientists to argue about."

NASA is also planning to send a mission to Europa, one of the four major moons of Jupiter, which is currently planned for launch in 2022. The primary objective of the £1.4 billion ($2.1 bn) mission is to shed light on the icy moon's potential habitability, but in doing that it could also search for signs of life in the plumes of water vapour that apparently erupt from Europa's South Pole.

It really does seem possible that alien life forms, of some kind, could be discovered in our very own solar system in the not too distant future – a very exciting possibility.