The number of exoplanets continues to grow

Exoplanet is by definition any planet outside our solar system. As of September 2012, astronomers have discovered more than 800 exoplanets, varying from scorching hot worlds with molten surfaces to extremely cold ice balls.

The astronomers hope that one day they will be able to find new Earth, the so called “Superearth”, a planet with roughly the same characteristics as Earth, the one that has the ability to sustain life.

The quest for this planet still goes on but nonetheless researchers say that life might actually be able to survive on some of the currently found exoplanets, despite the extreme conditions. Of course, if there were to be life on these planets then this would have to be some extreme life forms.

The astronomers look for exoplanets in so called habitable zone, namely at just the right distance from its Sun. The habitable zone is „not too hot and not too cold“ area, primarily determined by the size and heat of the star.

The astronomers have also discovered that there are some exoplanets that only spend some time within the habitable zone because many of these planets travel in very oblong, eccentric orbits that vary greatly in distance from their stars. This means that conditions on these planets could exchange between very cold and extremely hot.

Even in these extreme conditions, there is still a chance for alien life on these planets. The researchers have already found certain forms of life on earth that can survive in long-lasting, cold or hot conditions.

Earth-based spores, bacteria and lichens, for instance, were able to survive in both harsh environments on Earth and the extreme conditions in our Universe.

These planets are unlikely to support human-like life forms but could still support other life forms such as lichens and bacteria, to survive.

We also need to know that our astronomical knowledge about the habitability on currently discovered exoplanets is very limited, subject to guesses and speculations, because scientists still don't posses any data about the atmosphere of these planets. 

The presumption that we should look life just on planets that look like our own doesn't have to be necessarily true, especially given the fact that we still have so many unanswered questions about the life on our planet. It's Universe, meaning everything is possible.