Spitzer, Hubble Join Forces To Hunt Faraway Watery Worlds

Photo Credit: NASA

Scientists have discovered more than 5,000 exoplanets to date. However, most of the information known about them is basic. Researchers can find a planet’s radius or mass and how far it is from its host star, but it’s difficult for them to predict what these planets are actually like.

However, leveraging new techniques and tools, researchers to understand more details, such as a planet’s density, enabling them to understand what these other worlds are like. Recently, researchers have used data gathered from the Hubble Space Telescope and Spitzer Space Telescope to identify two watery planets featuring oceans that are 500 times deeper than the oceans of Earth.

Planets Filled With Water

The Kepler Space Telescope discovered the planets Kepler-138 c and Kepler-138 d in 2014, but with the help of Hubble and Spitzer’s data, their densities were revealed. Research suggests up to half of the planets’ volume could be made of water. It has raised questions about the size and type of these planets.

“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,” said researcher Björn Benneke of the University of Montreal.

“However, we have now shown that these two planets, Kepler-138 c and Kepler-138 d, are quite different 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 astronomers theorized to exist for a long time.”

Nothing Like Our Solar System

To imagine what these watery planets are like, experts believe we shouldn’t think of any planet in our solar system but so of the moons.

“Imagine larger versions of Europa or Enceladus, the water-rich moons orbiting Jupiter and Saturn, but brought much closer to their star,” said Caroline Piaulet, lead author. “Instead of an icy surface, they would harbor large water-vapor envelopes.”

However, these planets might be similar to any place in our solar system as they have extremely hot atmospheres. They might feature a thick atmosphere of steam with liquid water at high pressure underneath.