Too Much Water Makes Exoplanets 'Less Habitable'

For years, many space agencies and organizations devoted their time in searching for Earth-like planets with suitable and habitable conditions for human life. One of the main components to consider is the presence of liquid water. However, recent reports say that, like everything in life, too much of something is also not a good sign. Excessive amounts of water may also make exoplanets less habitable.

Water is one of the vital requirements for life. However, looking at it in a complex formation and evolution point of view, too much of it may hinder the progression of some life forms. This is considered true when it comes to the search for Earth 2.0 or the next habitable planet.

Last August, the European Space Observatory (ESO) announced that scientists found evidence that an exoplanet within Alpha Centauri may be able to sustain life. The discovery lead to many speculations and ideas on how a human habitation might thrive someplace beyond the Earth.

The recent Earth-like exoplanet is called Proxima B and it orbits the star Proxima Centauri. However, there is not a lot of information available yet about the exoplanet. Apparently, the exoplanet affects the tiny star making it "wobble" a little.

Although there is very little knowledge about Proxima B, the thought of having another Earth ignited the excitement of many.  Proxima B is also found in the Goldilocks Zone, meaning it is located at the right distance from the Sun to be able to sustain life. It won't be too hot or too cold and that liquid water may exist.

In theory, where there is liquid water, there is life. But a recent study from the University of Bern said that the problem is that small exoplanets may have too much or very "large quantities" of water.  

"Our models succeed in reproducing planets that are similar in terms of mass and period to the ones observed recently," Yann Alibert, of the Center of Space and Habitability (CSH) at the University of Bern, said in a statement. "Interestingly, we find that planets in close-in orbits around these type of stars are of small sizes. Typically, they range between 0.5 and 1.5 Earth radii with a peak at about 1.0 Earth radius. Future discoveries will tell if we are correct," Alibert added.

The study will be published in the journal Astronomy & Astrophysics. What makes the study more intriguing is that, if the model is correct, exoplanets may contain 10 percent water. This amount is excessive compared to Earth's 0.002 percent, according to reports.

Although this does not suggest that the exoplanets may not be habitable at all, but scientists think it may "lessen" its chance of being habitable due to too much liquid water.

"While liquid water is generally thought to be an essential ingredient, too much of a good thing may be bad," Willy Benz, the study co-author said in a statement. "But this is the case for the Earth, here we deal with considerably more exotic planets which might be subjected to a much harsher radiation environment, and/or be in synchronous " Benz added.

A body with too much water means there will also be a more complex weather system. But the proponents of the study, whether or not these types of exoplanets, with huge deposits of liquid water, may be habitable or not, understanding them will be beneficial to scientists in the future.