WASP-39b is part of the Virgo constellation. It sits 20 times closer to its star (named WASP-39) than Earth is to the sun. Unlike Earth, it doesn't rotate—only one side of the planet faces the star. That means there are extreme temperatures on WASP-39b, as high as 1,430 degrees Fahrenheit on the star-facing side.
The fact that WASP-39b has so much water means that it formed in a very different way than Saturn. NASA believes that the exoplanet probably formed far away from the star it orbits, where it picked up a lot of ice, and then migrated towards the star, until its ice melted into water vapor. According to the researchers, this means WASP-39b might have “obliterat[ed] planetary objects in its path”.
Studying exoplanets is an important way to learn more about the universe. The more planets we study, the more we understand the amazing diversity of how they are formed.
“We need to look outward so we can understand our own solar system,” lead researcher Hannah Wakeford of the Space Telescope Science Institute in Baltimore, Maryland, and the University of Exeter in Devon, United Kingdom said in NASA's press release.
“But exoplanets are showing us that planet formation is more complicated and more confusing than we thought it was. And that’s fantastic!”