This is an animation of the January 2017 Jupiter heatwave. Scientists used spectroscopic data from the Keck II Telescope at Mauna Kea, Hawaii, to create the heat map. It is superimposed on a Hubble image of Jupiter. Now, based on data from the Juno spacecraft, scientists think a powerful solar wind wave slammed into Jupiter’s magnetic field. As a result, it created intense auroras that heated the upper atmosphere at the pole, and that heat spilled down to lower latitudes. Video via James O’Donoghue.
- In 2017, a powerful solar wind burst compressed Jupiter’s magnetic field. Scientists were able to observe the effects of it for the first time.
- The compressed magnetic field triggered intense auroras at Jupiter’s poles, which heated the upper atmosphere. Then, that heat spilled down to lower latitudes.
- This study helps improve understanding of how solar wind affects planets like Jupiter and provides insights into solar storms that could impact Earth’s technology, such as GPS and power grids.
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Scientists surprised by heatwave on Jupiter
The sun constantly emits a flow of charged particles, called the solar wind, that spreads across our solar system. The intensity of this solar wind can vary, sometimes erupting out of the sun as a powerful burst. In January 2017, one such strong burst slammed into Jupiter, and for the first time, scientists were able to observe it. Scientists from the University of Reading in the U.K. said on April 3, 2025, that the burst compressed the Jovian magnetic field, resulting in intense auroras. That, in turn, heated the upper atmosphere, and the heat spilled across an enormous area. Moreover, temperatures soared to over 930 degrees Fahrenheit (500 C), nearly 300 degrees F (170 C) higher than normal.
The scientists published their study of this event in the peer-reviewed Geophysical Research Letters on April 3, 2025.
Lead author James O’Donoghue of the University of Reading said:
We have never captured Jupiter’s response to solar wind before, and the way it changed the planet’s atmosphere was very unexpected. This is the first time we’ve ever seen a thing like this on any outer world.
A Jovian heatwave
O’Donoghue initially reported this Jovian heatwave, the first ever observed, in 2021. The Keck II Telescope at Mauna Kea, Hawaii, took those spectroscopic observations in January 2017. Scientists wondered, at that time, if that heatwave was due to upper atmospheric heating from intense auroras triggered by a strong solar wind wave.
Recently, O’Donoghue and his collaborators discovered new evidence linking this heatwave to a powerful solar wind impact. They found it in data about the Jovian magnetic field from the Juno spacecraft.
Moreover, the team thinks these heatwave events could be occurring on Jupiter two to three times each month.
What happened on Jupiter?
Normally, Jupiter’s powerful auroras create upper atmosphere energy in polar regions. Then this energy gets redistributed as a gradual decrease toward the equator. However, this event had a more extreme effect on the planet’s upper atmosphere.
O’Donoghue described what happened:
The solar wind squished Jupiter’s magnetic shield like a giant squash ball. This created a super-hot region that spans half the planet. Jupiter’s diameter is 11 times larger than Earth’s, meaning this heated region is enormous.
Compression of the magnetic field allowed intense auroral activity at the poles, heating the planet’s upper atmosphere. This, in turn, caused hot gases in the upper atmosphere to expand and spill toward the equator.
The scientists were surprised to see such extensive heating across Jupiter. They thought that strong winds generated by the planet’s rapid rotation would have kept the hot gases confined to the polar regions. However, this discovery indicates that the atmospheres of planets in our solar system are more strongly affected by solar wind than scientists previously thought.
In 2016, the Hubble Space Telescope took these images of polar auroras on Jupiter in ultraviolet light. Video via NASA.
Comparing Jupiter to Earth and other planets
O’Donoghue commented:
We’ve studied Jupiter, Saturn and Uranus in increasing detail over the past decade. These giant planets are not as resistant to the sun’s influence as we thought – they’re vulnerable, like Earth. Jupiter acts like a laboratory, allowing us to study how the sun affects planets in general. By watching what happens there, we can better predict and understand the effects of solar storms which might disrupt GPS, communications and power grids on Earth.
Co-author Matthew Owens of the University of Reading added:
Our solar wind model correctly predicted when Jupiter’s atmosphere would be disturbed. This helps us further understand the accuracy of our forecasting systems, which is essential for protecting Earth from dangerous space weather.
A video animation of auroras on Earth, Jupiter and Saturn. Video via James O’Donoghue.
The solar wind and its impact on planets
Solar wind is made up of charged particles – mostly protons and electrons – streaming out of the sun. It originates from the outermost layer of the sun called the corona.
These particles stream out into the solar system at various speeds, densities and temperatures depending on how they’re released. As they rush out of the sun, they pull the sun’s magnetic field with it. And since the sun rotates every 27 days, you can visualize solar winds as spiraling out of the sun.
The magnetic field of a planet directs solar wind around the planet, acting like a shield. However, some charged particles infiltrate the upper atmosphere from polar regions. There, they interact with gas molecules to emit light and heat. On Earth, we see these interactions as auroras. These interactions also manifest as auroras on other planets with atmospheres such as Jupiter, Saturn and Uranus.
Bottom line: A strong solar wind wave slammed into Jupiter, compressing its magnetic field and creating intense auroras followed by a widespread heatwave.
Source: Sub-Auroral Heating at Jupiter Following a Solar Wind Compression
Via University of Reading
Read more: Auroras on Jupiter’s moons seen in new light
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