Astronomers at NASA’s Chandra X-ray Observatory have detected X-rays on the planet Uranus for the first time.
The researchers used observations of the ice giant made in 2002 and 2017 to detect radiation as part of a new study published Tuesday in the Journal of Geophysical Research.
In an examination and further analysis, they saw a clear detection of X-rays from the first observation and a possible appearance of X-rays in those 15 years later.
Scientists believe that the sun could be the driving force behind Uranus to emit X-rays.
Astronomers have previously observed that both Jupiter and Saturn scatter X-ray light from the sun.
However, while the study’s authors say they believe the detected X-rays come from “scattering,” another source of X-rays is likely.
Like Saturn, they say, Uranus’ rings could even produce X-rays or even the planet’s aurora – a phenomenon created when high-energy particles interact with the atmosphere.
“Uranus is surrounded by charged particles such as electrons and protons in its nearby space environment,” Chandra’s X-ray Observatory said in a statement. “If these energy particles collide with the rings, they could cause the rings to glow in X-rays.”
X-rays are emitted in the Earth’s auroras, and Jupiter also has auroras, although the X-rays in Jupiter’s auroras come from two sources.
However, an almost identical NASA version notes that researchers remain uncertain about the causes of the auroras on Uranus.
The agency wrote that the unusual orientations of its axis of rotation and magnetic field could make the planet’s auroras “unusually complex and variable.”
The axis of rotation of Uranus is almost parallel to its path around the sun – unlike the axes of other planets in the solar system – and while Uranus is tilted to its side, its magnetic field is plated with a different amount.
“Determining Uranus’ X-ray sources could help astronomers better understand how more exotic objects in space, such as growing black holes and neutron stars, emit X-rays,” NASA wrote.
Uranus is the seventh planet from the sun in the solar system. It has two sets of rings around its equator. Its diameter is four times that of the Earth.
Because Voyager 2 was the only spacecraft to ever fly with Uranus, astronomers rely on telescopes like Chandra to learn more about the cold planet, which is made up almost entirely of hydrogen and helium.