A University of Oxford-led study has identified a new type of exoplanet with sulfur-rich magma oceans located about 35 light-years from our solar system.
Typically, planets are classified as small, rocky worlds or large gas giants. L 98-59 d appears to fit neither category.
The planet is about 60% larger than Earth but has little in common with it. Scientists say L 98-59 d has a much lower density than Earth, and it differs significantly from gas giants such as Jupiter and Saturn.
RELATED STORY | NASA spacecraft weighing over 1,300 pounds will crash back down to Earth
L 98-59 d has a hydrogen-rich atmosphere filled with sulfur gases. Its surface is believed to consist mostly of molten silicate mantle, extending deep into the planet.
Researchers believe the vast magma ocean has stored large amounts of sulfur over billions of years, contributing to its distinctive atmosphere. They also suggest chemical reactions between the magma and radiation from the planet’s host star could be responsible for its sulfur-rich composition.
The planet may have once resembled Neptune but gradually cooled and lost part of its atmosphere, evolving into its current form.
“What’s exciting is that we can use computer models to uncover the hidden interior of a planet we will never visit,” said Raymond Pierrehumbert, professor of physics at the University of Oxford, in a press release. “Although astronomers can only measure a planet’s size, mass and atmospheric composition from afar, this research shows that it is possible to reconstruct the deep past of these alien worlds—and discover types of planets with no equivalent in our own solar system.”
RELATED STORY | NASA's first crewed mission to the moon since Apollo targeted for April launch
