Having discovered a myriad of planetary systems and myriad of planets previously unknown to humanity, the scientists shifted their focus to the new goal: find life outside
10. Dying Red Giant Stars
Even though the dying red giants themselves do not have the potential to harbor life, they can possibly bring the dead planets back to life by defrosting the ice on their surface. Stars turn into red giants before their death, releasing the amounts of radiation enough to melt down the ice of an exoplanet or the moon. After the process is completed, the exoplanet would have a liquid ocean on its surface and with it the potential to harbor life.
There is not really much hope for Venus to have any possible life, but there are still researchers who believe the opposite. The planet has thick clouds of sulfuric acid, which some scientists believe can harbor floating life. Venus has its own bacteria, similar to bacteria on Earth, and these bacteria can potentially evolve into more complicated forms of life.
8. Orion Nebula
A diffused nebula in the Milky Way, Orion Nebula is said to have signs of organic chemicals, which are required for the life to exist. There is a possibility that this nebula has water, methanol, sulfur oxide, sulfur dioxide, formaldehyde, and many others.
There are numerous exoplanets in the galaxy, which means there can be places where life might exist and no one on Earth would even know about them. There are many systems in the galaxy, like our solar system, but with a different star at the center and different exoplanets orbiting it. Humans started the exploration of those systems and planets only within the past ten years, finding organic materials here and there, but no sufficient evidence was found to prove the existence of life yet.
One of the Jupiter’s moons makes it to the list due to its high geological activity. The planet’s surface has more than 400 active volcanoes, whose activity resulted in a gas atmosphere around Io containing something similar to oxygen. In addition, the volcano activity regularly produces heat. However, there is not a big chance that Io has the same potential as the other places where life might exist further on our list, because there is no water or organic chemicals, as well as because it receives a large amount of radiation from Jupiter.
5. Ganymede and Callisto
These two Jupiter’s moons are thought to have water under their surfaces. However, the layers of rock that cover that water reaches 60 miles in thickness, which makes research on whether there is life under these rock layers an extremely long-term project involving complicated technologies.
Europa’s surface is covered with a ten-mile layer of ice, and the scientists suggested a theory that under this layer of ice, Europa is hiding an ocean containing oxygen. If the theory is right, it means Europa has more water than any other places where life might exist and even more water than the Earth. The ten-mile ice layer, however, makes it difficult to not only prove the existence of the ocean but also collect any kind of probes.
Similar to Europa, Enceladus’ surface is covered with a layer of ice mixed with crust, but the layer is thinner. The southern hemisphere of this Saturn’s moon potentially has a subsurface ocean, constantly shooting out water vapor. This vapor has organic molecules that humans presume necessary to harbor life: carbon, oxygen and nitrogen. The next step is to analyze the vapor for the presence of microorganisms.
2. Titan (Saturn’s Moon)
Titan has a potential for the life to survive because of its thick atmosphere. It mostly consists of nitrogen, with some presence of methane and oxygen. Unlike our #7 Io, Titan’s atmosphere can protect life from radiation. In addition, Titan is the second body in space (after Earth) to have liquid lakes. There are many chemical processes going on its surface, and that encourages scientists to believe that further probes might discover life organisms.
Mars takes the first place on our list. Since it is closer to Earth than above mentioned planetary bodies, it is better researched, and the results of the research have been encouraging so far. The scientists found the traces of water potential across the planet: evidence of having lakes in the past, ice caps covering the poles, and traces of water in the planet’s soil. The samples of soil, rocks, or ice did not prove the current existence of life on Mars. The researchers, however, are looking for the evidence to prove that the planet used to harbor life in the past.