Vast oceans beyond earth and the possibility for life nearer than we originally thought

Image source here

When I was a child and looked up at the starry sky I couldn't possibly comprehend that in most cases every shining dot up there, was actually a sun burning bright somewhere unfathomably far. I couldn't know that most of the brilliant stars were actually two, three or even four suns orbiting somehow each other, appearing as a single shining point at the sky because of its extreme distance from us. A few decades ago we thought that the formation of planets around a sun was a very rare occurrence and now we think that most stars probably have planets orbiting them.

So the million dollar question is that if there are so many planets around , is there a possibility for life to emerge and evolve, maybe even to an intelligent one somewhere? In order to get a perspective have in mind that in our galaxy only, we speculate that there are approximately 100-400 billion stars(source here)and that the galaxies in the observable universe are at least two trillion(source here). I suggest not to bother with the mathematics and just let your imagination run wild! As many astronauts have quoted in the past 'It is arrogant to think that we are alone in a universe so unimaginably vast' but due to that immense size we would need, with present technology, more or less seventy thousand years to travel to the nearest, three star ,system of Alpha Centauri. So as you can see, it is very difficult to get proof that some kind of life exists somewhere because everything is very,very far away from us but what about our own neighborhood , what about the planets in our own solar system and most importantly what about the moons orbiting some of them..

Europa , Image source here

There is a moon orbiting Jupiter called Europa five times further from the sun than earth, it is a bit smaller that our own moon but harbors a magnificent secret. Many miles beneath its icy crust we presume that there is a salty ocean in contact with its rocky interior, heated by the enormous tidal forces the giant planet enforces about its moon. Life seems promising there, that's why NASA is going to send a probe to investigate thoroughly, with the formal name 'Europa Clipper,' sometime in the 2020s(source here)and it is not the only mission planned for that region of space. ESA is also going to send a probe called JUICE(source here)to observe not only Europa , but also Ganymede and Callisto two more of Jupiter's moons that are supposed to possess someway or another liquid oceans beneath their crusts.

Image source here

At approximately eleven times further that earth is to the sun there is Saturn, and among its many moons there is a small one with only 157 miles(252 km) radius called Enceladus. Like Europa, it is heated by Saturn's tidal forces and the water vapor geysers that are elusive to observe at Jupiter's moon, are proven beyond doubt to erupt at Enceladus offering physical proof that an ocean is heated beneath its surface(source here). On the other hand if life of some kind exists on Titan which orbits Saturn and is the second largest moon of our solar system, it would be totally different from everything we know so far. Titan has lakes and rivers and rain falls upon its surface but the liquid involved in this case is not water. It is a big moon, actually it is even larger than planet Mercury, so it has a considerable mass, among others, in order to hold a dense cloudy atmosphere which coupled with its very low temperatures of approximately -290 Fahrenheit (-179 Celsius) made liquid natural gas(ethane and methane) to fall as rain and pool on its surface. It was recently discovered that there is a certain chemical in Titan's atmosphere that could be the basis to form cell membranes, of a different kind than those we are used to, but until we sent a probe dedicated to investigate further, we can only speculate(source here).

Titan , (Image source here)

Titan is believed to be another ocean world holding vast amouns of water beneath its exotic surface and the same seems to be happening at the moons Dione, Mimas and Triton even at Pluto which was demoted to the status of dwarf planet eleven years ago.

Mars(Gale Crater) , (Image source here)

Mars had rivers and lakes once but now its remaining water hides beneath its surface or lays frozen at its poles. Robotic rovers scout its ground as we speak for proof of some kind of microbial life of the past, while satellites orbit the cold desert planet investigating from afar and who knows, maybe one of these days the great discovery will be announced.

Water is abundant in our solar system, it is almost everywhere and our experience has taught us that where there is water interacting with rock that is somehow heated, life usually emerges...