Image credit: X-ray: NASA/CXC/UCL/W.Dunn et al, Optical: NASA/STScI
In case you thought Jupiter couldn’t get any cooler, a paper in the Journal of Geophysical Research has laid out evidence that solar storms are causing Jupiter’s auroras (think the Northern Lights, the Southern Lights, or that scene from Brother Bear) to brighten by almost eight times their usual brilliance.
The interaction was spotted by NASA’s Chandra X-ray Observatory, a telescope orbiting above the Earth to look for X-ray emissions in that big, old universe of ours.
Since Jupiter’s auroras are actually X-ray auroras, they can’t be spotted by the typical telescope (or by the human eye, if any of you were hoping to plan future vacations there). Chandra was able to observe key changes in Jupiter’s X-ray auroras when a particularly wicked solar storm, or coronal mass ejection (CME), hit Jupiter.
The sun is always spitting out streams of particles, but CME’s are much more dramatic: billions of tons of particles, bubbles of gas and magnetic fields, travelling millions of miles an hour. When a CME reached Jupiter in 2011, Chandra collected 11 hours of data, repeating the process two days later when the solar storm had moved on.
The data showed that the 2011 CME had a huge effect on Jupiter’s auroras.
The CME compressed Jupiter’s magnetic field, “shifting its boundary with the solar wind inward by more than a million miles” (NASA). With help from the solar storm, Jupiter’s X-ray auroras emitted light eight times brighter than usual, energy hundreds of times that of the Northern Lights, over areas larger than Earth.
Auroras happen when charged particles moving at a high speed interact with a planet’s atmosphere. On Earth, we can thank solar wind for our visible auroras. The sun sends us a breeze of highly charged electrons, which interact with the elements in Earth’s atmosphere to give us one heck of a light show.
Although our ill-equipped human eyes can’t see them, Jupiter’s X-ray auroras occur in a similar way. The auroras don’t just occur during a CME, but the massive solar storms trigger and accelerate the aurora, and therefore explain why and how Jupiter’s auroras act the way they do.
So what does this tell us about Jupiter, the Earth, and our solar system? Why should I care? Will this help us find aliens?
NASA’s Juno spacecraft is set to arrive at Jupiter on July 4 this year to study the aurora and to poke around the giant gas planet for more fun science discoveries. However the evidence compiled in the Journal of Geophysical Research already gives us insight into how the Sun influences other planets, as well as our own.
Science is slow, my friends, but any extra knowledge about the universe is good news for us and our tiny little terrestrial planet.