While we’ve discovered more than 5,000 exoplanets, most of the information we have about them is fairly basic. Researchers usually know a planet’s mass or radius and its distance from its host star, but little more than that, which makes it hard to predict what will happen. What these worlds look like in reality.
However, new tools and technologies are allowing researchers to learn more about details such as the planet’s density, allowing for a better understanding of what these places look like.
More recently, researchers using data from the Hubble Space Telescope and the Spitzer Space Telescope identified two planets that appear to be water worlds, with oceans 500 times deeper than Earth’s, Digitartlends reported.
The planets Kepler-138 c and Kepler-138 d were first identified by the Kepler Space Telescope in 2014, but it wasn’t until recently that data from Hubble and Spitzer were used to reveal their densities.
Research shows that up to half the size of planets can be composed of water, which raises questions about planets of this size and type.
“These two planets, Kepler-138 c and d, are very different in nature and much of their entire volume likely consists of water,” one of the researchers, Björn Benneke of the University of Montreal team, said in a statement. “It is the best evidence for water worlds, which are a type of planet.” Astronomers have assumed its existence for a long time.
To visualize what these watery worlds are like, experts say we should think not of any of the planets in our solar system but of some of their moons.
“Imagine larger versions of Europa or Enceladus, the water-rich moons that orbit Jupiter and Saturn, but come very close to their star,” said lead author Caroline Beaulet of the Trottier Institute for Exoplanet Research. “Instead of an icy surface, they would have large envelopes of Water vapor.”
However, these planets wouldn’t really be similar to anywhere in our solar system because the planets in question have very hot atmospheres. Instead they likely have a dense atmosphere of vapor with liquid water under high pressure.
Although this seems unusual, we may find more similar worlds in the future, Beneke said, “As our instruments and techniques become sensitive enough to find and study planets far from their stars, we may start to find a lot of these water worlds.”