Scientists from Harvard University say one in three of the exoplanets discovered contained more water than Earth. This suggests they can support life just like planet Earth.

Specifically, 35 percent of the exoplanets with sizes bigger than Earth is found to be abundant with water, as 50 percent of their weight is comprised of the colorless liquid. In comparison, Earth's weight is only composed of 0.02 percent of water.

The team believed that these exoplanets, now referred to as water-worlds, formed similarly with how Jupiter, Saturn, Uranus, and Neptune were formed. Since they are two to four times larger than Earth, these water-worlds may provide the best chance of supporting new life, the scientists said.

The Water-Worlds

For their study, which was presented at the Goldschmidt conference in Boston on Aug. 17, the scientists used the data from NASA's Kepler Space Telescope and the Gaia mission. The group of international experts analyzed the exoplanets with regard to their mass measurements and radius measurements. The group then created a general model of the exoplanet's internal structure.

The model showed that those exoplanets with a radius of about 1.5 times the Earth radius consist of rocks that are about five times the mass of Earth. On the other hand, the exoplanets with a radius of about 2.5 times the Earth's radius and a mass of around 10 times that of Earth belonged to the group now referred to as water-worlds.

Dr. Li Zeng, the lead researcher from Harvard University, said the water in these exoplanets is not commonly found on Earth. For one, the water's surface temperature is expected to be about 300 to 900 degree Fahrenheit.

"Moving deeper, one would expect to find this water transforms into high-pressure ices before reaching the solid rocky core," Zeng explained.

"Life could develop in certain near-surface layers on these water worlds when the pressure, temperature and chemical conditions are appropriate," she added.


Exoplanets were discovered as early as 1992 orbiting around other stars. To date, scientists have found 4,000 of confirmed and candidate exoplanets and the interest in knowing whether they are suitable to develop or support life are growing as ever.

NASA has specifically placed the number of confirmed exoplanets at 3,700. The agency said there could more of them, even tens of thousands of them. They may also be discovered as highly advanced and robotic telescopes are deployed into space.

For one, NASA's newly launched TESS mission aims to find more of the exoplanets. NASA's James Webb Space Telescope, on the other hand, aims to characterize the atmosphere of these Super-Earths.

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