Two distant planets may be "water worlds" •

Two distant planets may be "water worlds"


Today’s Video of the Day from NASA Goddard describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are “water worlds.”

The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.

“We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that’s why we called them super-Earths,” explained study co-author Björn Benneke. 

“However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time.”

Video Credit: NASA Goddard

Image Credit: NASA, ESA, and Leah Hustak (STScI)

By Chrissy Sexton, Editor

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