For the first time, Jupiter’s X-ray aurora has been studied as a giant solar storm arrived at the planet. When the giant storm from the sun arrived it generated a new X-ray aurora that was eight times brighter than normal, and hundreds of times more active than Earth’s aurora borealis.
According to the University College London (UCL), the dramatic findings complement NASA’s Juno mission this summer that aims to understand the relationship between the two biggest structures in the solar system — the region of space controlled by Jupiter’s magnetic field (i.e. its magnetosphere) and that controlled by the solar wind.
William Dunn, lead author and PhD student at UCL Mullard Space Science Laboratory, explained in a statement:
“There’s a constant power struggle between the solar wind and Jupiter’s magnetosphere. We want to understand this interaction and what effect it has on the planet.
“By studying how the aurora changes, we can discover more about the region of space controlled by Jupiter’s magnetic field, and if, or how, this is influenced by the sun.
“Understanding this relationship is important for the countless magnetic objects across the galaxy, including exoplanets, brown dwarfs, and neutron stars.”
The sun is constantly ejecting streams of particles into space in the solar wind. As giant storms erupt, the winds produced become much stronger which compresses Jupiter’s magnetosphere; this effect shifts its boundary with the solar wind 1,242,742 miles (two million kilometers) through space.
The study found that it is this interaction at the boundary that triggers the high energy X-rays in Jupiter’s Northern Lights, and covers an area bigger than the surface of Earth.
The new research used NASA’s Chandra X-Ray Observatory and was published in the Journal of Geophysical Research — Space Physics. This discovery comes while NASA’s Juno spacecraft is nearing Jupiter for the start of its mission this summer.
Juno was launched in 2011 with the aim of unlocking the secrets of Jupiter’s origin, which could help us gain a better understand of how the solar system — including Earth — formed.
Part of Juno’s mission is to examine Jupiter’s relationship with the sun and solar winds by studying its magnetosphere, aurora, and its magnetic field. The researchers are hoping to discover how the X-rays form by collecting complementary data using the European Space Agency’s X-ray space observatory, XMM-Newton, and NASA’s Chandra X-ray observatory.
Study supervisor, Professor Graziella Branduardi-Raymont, UCL Mullard Space Science Laboratory, said:
“Comparing new findings from Jupiter with what is already known for Earth will help explain how space weather is driven by the solar wind interacting with Earth’s magnetosphere.
“New insights into how Jupiter’s atmosphere is influenced by the sun will help us characterize the atmospheres of exoplanets, giving us clues about whether a planet is likely to support life as we know it.”
To track the impact of solar storms on Jupiter’s aurora, the team monitoring the X-rays emitted over two, 11 hour observations in October 2011; this was when an interplanetary coronal mass ejection from the sun was predicted to reach the planet.
The scientists then used the data to build a spherical image to determine the source of the X-ray activity and identify areas to investigate further at different time points, UCL wrote.
Dunn added that:
“In 2000, one of the most surprising findings was a bright ‘hot spot’ of X-rays in the aurora which rotated with the planet. It pulsed with bursts of X-rays every 45 minutes, like a planetary lighthouse.
“When the solar storm arrived in 2011, we saw that the hot spot pulsed more rapidly, brightening every 26 minutes. We’re not sure what causes this increase in speed but, because it quickens during the storm, we think the pulsations are also connected to the solar wind, as well as the bright new aurora.”