There are seven Earth-sized planets orbiting around TRAPPIST-1, a distant star. Scientists have been observing the way each planet interacts with the others to gain valuable information about its composition. By doing so, they have found that a few of these planets could house as much as 250 times more water than the amount in Earth’s oceans combined.

Studying these planets is a challenge for the researchers at the University of Bern in Switzerland. The entire system is 39 light-years away from Earth, making it impossible with current technology to send any type of observatory probe or robot. Scientists have determined that the planets orbit their sun in a very close pattern; so close that the gravity of one can make slight changes to the orbit of the plants surrounding it. Using an advanced algorithm, they were able to eventually estimate the mass of each planet. They could then make determinations about the density and composition of each planet in the system based on its mass.

Five of the lightest planets in this particular system could potentially hold up to 250 times more water than that contained in all of the oceans on Earth. Three of those five planets, TRAPPIST-1c, d, and e, likely get enough radiation from the star they orbit for the water to exist as a liquid on their surfaces.

The possibility of water existing as a liquid on TRAPPIST-1e is especially existing. This planet is the most similar one to Earth in the system, as it shares comparable radiation levels, size, and density. Of all the ones in this system, it is mostly likely to be habitable.

There is still a lot to learn about these planets. This recent discovery can lead researchers to understand more about the composition and surface structure of the planets. Scientists and space enthusiasts alike hope to learn more about this complex system when NASA launches its James Webb Space Telescope in 2019.