March 1, 2018
Much like detectives who study fingerprints to identify the culprit, scientists used NASA’s Hubble and Spitzer space telescopes to find the “fingerprints” of water in the atmosphere of a hot, bloated, Saturn-mass exoplanet some 700 light-years away. And, they found a lot of water. In fact, the planet, known as WASP-39b, has three times as much water as Saturn does.
Though no planet like this resides in our solar system, WASP-39b can provide new insights into how and where planets form around a star, say researchers. This exoplanet is so unique, it underscores the fact that the more astronomers learn about the complexity of other worlds, the more there is to learn about their origins. This latest observation is a significant step toward characterizing these worlds.
Although the researchers predicted they’d see water, they were surprised by how much water they found in this “hot Saturn.” Because WASP-39b has so much more water than our famously ringed neighbor, it must have formed differently. The amount of water suggests that the planet actually developed far away from the star, where it was bombarded by a lot of icy material. WASP-39b likely had an interesting evolutionary history as it migrated in, taking an epic journey across its planetary system and perhaps obliterating planetary objects in its path.
“We need to look outward so we can understand our own solar system,” explained lead investigator Hannah Wakeford of the Space Telescope Science Institute in Baltimore, and the University of Exeter in Devon, United Kingdom. “But exoplanets are showing us that planet formation is more complicated and more confusing than we thought it was. And that’s fantastic!”
Image Credits: NASA, ESA, G. Bacon and A. Feild (STScI), and H. Wakeford (STScI/Univ. of Exeter)