NASA Astronomers Detect First X-rays From Uranus

NASA astronomers at the Chandra X-ray Observatory have detected X-ray emissions from Uranus. The X-ray emissions were detected from a 2002 and 2007 observation of the planet. Only one spacecraft has ever successfully approached Uranus.

The astronomers at Chandra X-ray Observatory used observations of the planet taken in 2002 and 2017 to detect the radiation. The observations were published as part of a new study that appeared Tuesday in the Journal of Geophysical Research. An examination and further analysis allowed clear detection of X-rays from the first observation 15 years ago. Previous observations have shown that both Jupiter and Saturn emit X-ray light from the sun. According to the study authors, the sun could be causing Uranus to emit X-rays, but they believe there could also be another source.

The study authors’ hypothesis’ is that like Saturn, Uranus’ rings could also be producing X-rays, or even aurora, a phenomenon created when electrically charged particles from the sun interact with the earth’s atmosphere. “Uranus is surrounded by charged particles such as electrons and protons in its nearby space environment. If these energetic particles collide with the rings, they could cause the rings to glow in X-rays,” explains a press release by Chandra X-ray Observatory astronomers.

The Earth’s and Jupiter’s auroras emit X-rays, though X-rays from the latter may come from two sources, researchers say. However, according to a NASA release, the source of emissions from Uranus is still unclear. NASA wrote that the unusual rotation axis of Uranus and magnetic field may be the source of the planet’s “unusually complex and variable” auroras. Unlike other planets in the solar system, Uranus’ rotation axis is almost parallel to its path around the sun. The ice planet’s magnetic field is also not closely aligned with its rotational axis. According to NASA, knowing what’s causing the X-rays from Uranus could help them better understand how other unusual objects in space, like black holes and neutron stars, produce X-rays.

Overall, Uranus, the seventh planet from the sun in the solar system, is four times that of Earth in diameter. It is mostly made up of hydrogen and helium and has two sets of rings around its equator. The only spacecraft to ever fly by Uranus is the Voyager 2, and astronomers rely on telescopes like Chandra to learn more about the planet.