Jul 22, 07:30 PM

NASA-Oxford Study Finds Uranus Emits Its Own Heat

Uranus, long considered the solar system’s cold outlier, does in fact generate measurable internal heat, according to a joint study by NASA and the University of Oxford. Using an advanced computer model that integrated decades of observations from instruments such as the Hubble Space Telescope and NASA’s Infrared Telescope Facility, researchers calculated that the ice giant emits roughly 15 % more energy than it absorbs from the Sun. The finding, published on 16 May in Monthly Notices of the Royal Astronomical Society, overturns conclusions drawn from Voyager 2’s 1986 fly-by, which suggested the planet lacked internal heat. Lead author Patrick Irwin of Oxford and NASA planetary scientist Amy Simon say the revised energy budget aligns Uranus more closely with Jupiter, Saturn and Neptune, all of which radiate leftover formation heat. Confirming an internal heat source reshapes theories about Uranus’s evolution—its unusual axial tilt and retrograde rotation—and offers insight into similarly sized exoplanets. The team plans follow-up observations to refine the heat estimate and probe the planet’s interior structure.