Call James Cameron: Two Distant Planets Could Be Filled With Water

Astronomers utilizing the Hubble Space Telescope have noticed two exoplanets that could be examples of a long-hypothesized planetary classification: a water world.

The planets are referred to as Kepler-138c and Kepler-138d and are situated in a star system 218 light-years away, in keeping with a release from the European Space Agency. The group, led by Caroline Piaulet of the Institute for Research on Exoplanets on the University of Montreal, used knowledge from Hubble in addition to NASA’s Spitzer Space Telescope to find out that the worlds are largely water, making them even wetter than our famously moist dwelling planet. Their findings are published in Nature Astronomy.

“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,” stated Björn Benneke, one in every of the examine authors, within the ESA launch. “However, we have now shown that these two planets, Kepler-138c and d, are quite different in nature and that a large fraction of their entire volume is likely composed of water.”

Kepler-138c and Kepler-138d are estimated to be roughly 3 times the scale of Earth and double our personal planet’s mass, however with a lot decrease densities.

The analysis group didn’t immediately observe water on the planets, however by evaluating the commentary knowledge to pre-existing fashions, they discovered that they ought to encompass supplies with a density between the gases hydrogen and helium and rock—and the possible candidate is water. With that stated, the researchers consider these planets may have extremely scorching atmospheres, that means their surfaces may not be teeming with huge liquid oceans.

“The temperature in Kepler-138d’s atmosphere is likely above the boiling point of water, and we expect a thick dense atmosphere made of steam on this planet,” stated Piaulet. “Only under that steam atmosphere could there potentially be liquid water at high pressure, or even water in another phase that occurs at high pressures, called a supercritical fluid.”

Some of the primary direct proof for the existence of water worlds was found 2012, however subsequent observations have been laborious to return by. A examine in 2017 prompt that these water worlds may make up a big proportion of probably liveable exoplanets. Other analysis in 2019 discovered that exoplanets bigger than Earth—just like the Kepler-138 planets—may possible be water worlds with extremely deep oceans.

While the latest findings are thrilling, the analysis group is wanting ahead to follow-up work utilizing the Webb Space Telescope to additional examine the atmospheres of Kepler-138c and d.