With scientists finding more and more planets outside of our solar system, it may be time to start thinking about which of them could be habitable for carbon-based life.
Researchers at the University of East Anglia recently published a paper in the journal Astrobiology explaining the role that oceans play in the formation of life, and in sustaining life. This is an important step in possibly finding a planet that can support alien life.
"The number of planets being discovered outside our solar system is rapidly increasing," said David Stevens, one of the researchers, in a news release. "This research will help answer whether or not these planets could sustain alien life."
Previously, research to find climates on Earth-like planets that scientists thought could sustain life focused on the atmospheres of the planets. But oceans are also important, as explained in this new research. Oceans mediate the effect of climate on planets, which helps to make them mild enough to support life. The researchers created a computer simulation showing the effect of oceans on a hypothetical planet covered in ocean. The simulation showed that oceans slowed down and evened distribution of heat on planetary surfaces.
The lack of oceans on Mars, for example, means that the temperature fluctuates drastically on a daily basis. Professor David Stevens from UEA's school of Math said, "Mars for example is in the sun's habitable zone, but it has no oceans - causing air temperatures to swing over a range of 100OC. Oceans help to make a planet's climate more stable so factoring them into climate models is vital for knowing whether the planet could develop and sustain life."
Stevens said, "We know that many planets are completely uninhabitable because they are either too close or too far from their sun. A planet's habitable zone is based on its distance from the sun and temperatures at which it is possible for the planet to have liquid water. But until now, most habitability models have neglected the impact of oceans on climate. Oceans have an immense capacity to control climate. They are beneficial because they cause the surface temperature to respond very slowly to seasonal changes in solar heating. And they help ensure that temperature swings across a planet are kept to tolerable levels."
Even previous studies which did consider oceans used an "aquaplanet" model, the study said, which is an overly simplified model that neglects to consider the effect of land barriers on ocean.
Stevens said, "We found that heat transported by oceans would have a major impact on the temperature distribution across a planet, and would potentially allow a greater area of a planet to be habitable."
