Life as We Don't Know it

Life in general is very fragile. It only takes one thing to go wrong for it to end, but it takes many things to go right for it to thrive. Fortunately for us, Earth happens to be the only known planet where everything has gone right. There are hundreds of billions of unknown planetary bodies through out the universe and possibly more than that. So even if Earth is a one in a million, or even a one in a billion, that means that there are hundreds of other planets in the universes like Earth. Or, on the other end of the spectrum, Earth could possibly be the one and only of its kind, but I find this hard to believe given the massive number of planets that are out there.

This is why I believe that aliens do exist. Although, I do not believe in any of the conspiracy theories out there about Area 51, UFOs, etc. I refuse to believe in any such things until hard proof surfaces and the scientific community accepts it. The aliens that I am referring to are organisms that are still at the cellular level. I believe that there are planets out there that support single or multi-cellular organisms. Life, although fragile, is resilient in that it can exist in extreme environments like at the bottom of the ocean or where the sun never shines. This means that it is not that hard for life on a planet with extreme environments.I also believe that there could be organisms that are evolved to the point where they are full-grown animals. These two examples of alien life seem the most likely to me, especial cellular life, but I do recognize the possibility of a planet that is home to intelligent life. For all we know, there could be a species out there that has technology that is centuries ahead of our own, or they could still be in a stone age. Even if life does exist elsewhere, it could be on the other side of the universe where humans will never venture. Most anything is possible, but all of this is yet to be proven.

The Moons of Life

Most people are aware of Mars's possibility of supporting life, but what most people do not know is that there are two other planetary bodies in our solar system that could also support life. These two planetary bodies, however, are not quiet planets, they are moons. The first, and most likely to support life, is Europa, one of Jupiter's 4 moons. What makes Europa so special that it is completely covered in a layer of water ice. This ice makes the surface of Europa uniquely smooth, and bright from the light that is reflected from it. Europa's surface consists of large, continent sized ice plates with cracks in between them. The cracks indicate that the plates move which also indicates that there is water underneath that has tidal properties. Europa's ice is thought to be just a thin crust that could just be 3 miles deep or less. While underneath could be up to 30 miles of liquid water. The fact that there is water underneath could indicate that the water is warmer at greater depths. This heat is mostly likely caused by tidal movements caused by gravitational interactions with Jupiter. With the presence of liquid water and some heat from gravity, there is a possibility that a form a life exists, like how life still exists at the bottoms of Earth's oceans.

The second is Saturn's largest moon, Titan. Titan has an atmosphere denser than Earth's and is many composed of nitrogen, like Earth's, and is very cold. The amazing thing about Titan is its climate and atmosphere which allows for a stable liquid to exist on the surface, liquid methane and ethane. This means that Titan has a methane/ethane cycle that is very similar to Earth's water cycle that is so vital for the life that exists on Earth. This liquid cycle has caused Titan's surface to have many features that are similar to Earth's. In addition, Titan has a rich mixture of organic compounds that are essential for life to exist. Titan is suspected to support some time of micro-organism or, at the very least, has the chemistry needed to support life in a surface ocean. The only problem with Titan is that its cold temperatures could be preventing life to form.

Why Mars?

Mars is located in what is know as the "Goldilocks Zone", its not too cold, its not to hot, its just right. When a planet is in the Goldilocks zone, it is the perfect distance away from the sun so that it is not to  cold and it is not too hot. In our solar system, Earth and Mars are the only planets that are in the Goldilocks zone. For a planet to support life as we know it, said planet must be within the Goldilocks zone. The Goldilocks zone of a solar system my vary according to how big or hot that star is burning. If the star is burning very hot, then the Goldilocks zone will be much farther away than if it wasn't' burning very hot. This is the whole basis behind why we are so interested in Mars. If Venus was in the Goldilocks zone instead of Mars, then we would be working toward going there. If a planet is not considered to be within the Goldilocks zone, then is is automatically ruled out for a candidate for colonization. Although, just because a planet is not within the Goldilocks zone, that does not necessarily mean that it can not support some sort of life. Life as we know it depends on liquid water which requires a certain temperature to stay in liquid form. Although, for all we know, there could be some kind of life, whether it be complex for just single cell organisms, could depend on something else like liquid methane which exists in a stable liquid form on Saturn's moon, Titan (a subject for another post). If life does exist that depends on some other liquid, then that would create another Goldilocks zone for that certain liquid, but, frankly, that would be unimportant to the human race since humans probably would be able to live in that zone.