The Earth is a very special place. To our knowledge, we’re the only planet with life, and that’s significant. We owe a lot of our special circumstances to the presence of water, so naturally that’s the first thing we look for when we’re searching for life outside our solar system. Even if it’s extremely salty or in the form of life, it’s a step in the right direction. But does this even exist? What planets out there have water like Earth?
1. Our solar system has more than one.
We don’t have to look very far to discover water elsewhere. Mars, Neptune, Uranus, and Pluto all have ice and possibly liquid water. Aside from planets, several moons in the solar system also have ice and/or liquid water. These moons will be the subjects of future missions to search for life in the solar system.
2. Ocean worlds exist.
Picture Earth, but without any continents; just ocean. These types of planets exist, and we call them “water worlds” or “ocean words”. They aren’t rarities by any means.In fact, they’re quite common! Researchers have estimated that most planets between the sizes of Earth and Neptune are probably covered with water. In addition, these planets don’t just have a thin layer of ocean; some have been estimated to have 50% of their mass in water form, meaning their oceans are incredibly deep.
3. What does this mean for habitability?
The fact that many worlds are covered in oceans, rather than supporting the existence of alien life, might actually hurt our chances of finding it. When modeling these water worlds, researchers estimated that they could have surface temperatures of about 400 degrees F, a humid atmosphere made up of water vapor, and layers of ice surrounding the core. None of this sounds like a friendly environment for life, but until we won’t know for sure until we can get closer to these worlds.