Two far-off planets are likely made of water, according to research conducted using NASA’s Hubble and Spitzer telescopes.
The so-called “water worlds” are orbiting a red dwarf star, the smallest and coolest kind of star, according to a news release from NASA’s Jet Propulsion Laboratory.
The aqueous planets are 218 light-years away in the constellation Lyra, says NASA. And they’re “unlike any planets found in our solar system,” the agency said.
The finding that the planets are likely composed of mostly water comes from a study published in the journal Nature Astronomy on Thursday. A research team led by Caroline Piaulet, a PhD student at the University of Montreal’s Institute for Research on Exoplanets, used NASA’s Hubble and Spitzer space telescopes to observe the distant planetary system.
The planetary system they studied is called Kepler-138 because it’s located within the field of vision of NASA’s Kepler spacecraft. Researchers have known about the existence of three exoplanets – the term for planets outside our solar system – within the Kepler-138 system but have only just discovered two of them are likely made out of water.
They also discovered evidence for a fourth planet that hadn’t been described before.
But the finding isn’t as straightforward as it might seem. The scientists didn’t directly detect water at exoplanets Kepler-138c and Kepler-138d. Instead, they compared the sizes and masses of the planets to models for comparison.
When they compared the planets to the models, they found “that a significant fraction of their volume – up to half of it – should be made of materials that are lighter than rock but heavier than hydrogen or helium.”
Water is the likeliest candidate for a material that’s lighter than rock but heavier than hydrogen or helium, says NASA.
Source: CNN