This week, just days before NASA’s Juno spacecraft makes its historic dive into Jovian orbit, Hubble astronomers have released images of a gorgeous aurora twirling above Jupiter’s pole.
Auroras are a phenomena caused by the friction of charged particles and a planet’s magnetosphere. On Earth, the instigators are high-energy particles in solar wind, which collide with atoms of gas in the upper atmosphere near the magnetic poles. These atoms get excited, then lose their energy, ionize, and emit colorful light.
Jupiter’s auroras are also instigated by solar wind but the planet’s intense magnetic field brings other forces into play as well. When combined, the gas giant’s quick rotation and high-pressure hydrogen core — which experts think creates a sort of electrical conductor — generate an extreme radiation environment. These forces pull charged particles from solar wind and from surrounding objects such as Io’s active volcanoes. The results are auroras that hold hundreds of times more energy than those on Earth.
“Jupiter’s magnetic field is the most powerful in the solar system, and its magnetosphere behaves very differently to the Earth’s.” Jonathan Nichols of the University of Leicester, and principal investigator of the study, tells Digital Trends. “Jupiter also acts as an accessible analogue for more distant astrophysical bodies, such as pulsars and exoplanets.”
Jupiter’s auroras aren’t just more energetic than Earth’s — they’re bigger too. Much bigger. In fact, they’re at least as big as Earth itself.
“Each planetary magnetosphere acts as a natural laboratory for testing our understanding of space physics, and each one provides a different part of the story,” Nichols adds. “The auroras reveal the dynamic process occurring in a magnetosphere — they are the TV screen that shows us its overall behavior.”
These are just the first in a series of related images from the Hubble Telescope, which will continue to monitor Jupiter daily for about another month. In the meantime, the telescope will work in tandem with Juno, which will give additional data on the gas giant’s tremendous forces as it measures the solar wind itself from within the planet’s orbit.
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