NASA’s NuSTAR Spots Highest-Energy Light Ever Detected From Jupiter – And Solves a Decades-Old Mystery

NASA Juno Jupiter Southern Hemisphere

Jupiter’s southern hemisphere is shown in this image from NASA’s Juno mission. New observations by NASA’s NuSTAR reveal that auroras near both the planet’s poles emit high-energy X-rays, which are produced when accelerated particles collide with Jupiter’s atmosphere. Credit: Enhanced image by Kevin M. Gill (CC-BY) based on images provided courtesy of NASA/JPL-Caltech/SwRI/MSSS

The planet’s auroras are known to produce low-energy X-ray light. A new study finally reveals higher-frequency X-rays and explains why they eluded another mission 30 years ago.

Scientists have been studying Jupiter up close since the 1970s, but the gas giant is still full of mysteries. New observations by NASA’s NuSTAR space observatory have revealed the highest-energy light ever detected from Jupiter. The light, in the form of X-rays that NuSTAR can detect, is also the highest-energy light ever detected from a solar system planet other than Earth. A paper in the journal Nature Astronomy reports the finding and solves a decades-old mystery: Why the Ulysses mission saw no X-rays when it flew past Jupiter in 1992.

X-rays are a form of light, but with much higher energies and shorter wavelengths than the visible light human eyes can see. NASA’s Chandra X-ray Observatory and the ESA (European Space Agency) XMM-Newton observatory have both studied low-energy X-rays from Jupiter’s auroras – light shows near the planet’s north and south poles that are produced when volcanoes on Jupiter’s moon Io shower the planet with ions (atoms stripped of their electrons). Jupiter’s powerful magnetic field accelerates these particles and funnels them toward the planet’s poles, where they collide with its atmosphere and release energy in the form of light.

Jupiter's Magnetic Field Lines

Jupiter is shown in visible light for context with an artistic impression of the Jovian upper atmosphere’s infrared glow is overlain, along with magnetic field lines. Jupiter’s powerful magnetic field accelerates ions and funnels them toward the planet’s poles, where they collide with its atmosphere and release energy in the form of light. Credit: J. O’Donoghue (JAXA)/Hubble/NASA/ESA/A. Simon/J. Schmidt

Electrons from Io are also accelerated by the planet’s magnetic field, according to observations by NASA’s Juno spacecraft, which arrived at Jupiter in 2016. Researchers suspected that those particles should produce even higher-energy X-rays than what Chandra and XMM-Newton observed, and NuSTAR (short for Nuclear Spectroscopic Telescope Array) is the first observatory to confirm that hypothesis.

“It’s quite challenging for planets to generate X-rays in the range that NuSTAR detects,” said Kaya Mori, an astrophysicist at Columbia University and lead author of the new study. “But Jupiter has an enormous magnetic field, and it’s spinning very quickly. Those two characteristics mean that the planet’s magnetosphere acts like a giant particle accelerator, and that’s what makes these higher-energy emissions possible.”

Researchers faced multiple hurdles to make the NuSTAR detection: For example, the higher-energy emissions are significantly fainter than the lower-energy ones. But none of the challenges could explain the nondetection by Ulysses, a joint mission between NASA and ESA that was capable of sensing higher-energy X-rays than NuSTAR. The Ulysses spacecraft launched in 1990 and, after multiple mission extensions, operated until 2009.

NuSTAR X rays Jupiter

NuSTAR detected high-energy X-rays from the auroras near Jupiter’s north and south poles. NuSTAR cannot locate the source of the light with high precision, but can only find that the light is coming from somewhere in the purple-colored regions. Credit: NASA/JPL-Caltech

The solution to that puzzle, according to the new study, lies in the mechanism that produces the high-energy X-rays. The light comes from the energetic electrons that Juno can detect with its Jovian Auroral Distributions Experiment (JADE) and Jupiter Energetic-particle Detector Instrument (JEDI), but there are multiple mechanisms that can cause particles to produce light. Without a direct observation of the light that the particles emit, it’s almost impossible to know which mechanism is responsible.

In this case, the culprit is something called bremsstrahlung emission. When the fast-moving electrons encounter charged atoms in Jupiter’s atmosphere, they are attracted to the atoms like magnets. This causes the electrons to rapidly decelerate and lose energy in the form of high-energy X-rays. It’s like how a fast-moving car would transfer energy to its braking system to slow down; in fact, bremsstrahlung means “braking radiation” in German. (The ions that produce the lower-energy X-rays emit light through a process called atomic line emission.)

Each light-emission mechanism produces a slightly different light profile. Using established studies of bremsstrahlung light profiles, the researchers showed that the X-rays should get significantly fainter at higher energies, including in Ulysses’ detection range.

“If you did a simple extrapolation of the NuSTAR data, it would show you that Ulysses should have been able to detect X-rays at Jupiter,” said Shifra Mandel, a Ph.D. student in astrophysics at Columbia University and a co-author of the new study. “But we built a model that includes bremsstrahlung emission, and that model not only matches the NuSTAR observations, it shows us that at even higher energies, the X-rays would have been too faint for Ulysses to detect.”

The conclusions of the paper relied on simultaneous observations of Jupiter by NuSTAR, Juno, and XMM-Newton.

New Chapters

On Earth, scientists have detected X-rays in Earth’s auroras with even higher energies than what NuSTAR saw at Jupiter. But those emissions are extremely faint – much fainter than Jupiter’s – and can only be spotted by small satellites or high-altitude balloons that get extremely close to the locations in the atmosphere that generate those X-rays. Similarly, observing these emissions in Jupiter’s atmosphere would require an X-ray instrument close to the planet with greater sensitivity than those carried by Ulysses in the 1990s.

“The discovery of these emissions does not close the case; it’s opening a new chapter,” said William Dunn, a researcher at the University College London and a co-author of the paper. “We still have so many questions about these emissions and their sources. We know that rotating magnetic fields can accelerate particles, but we don’t fully understand how they reach such high speeds at Jupiter. What fundamental processes naturally produce such energetic particles?”

Scientists also hope that studying Jupiter’s X-ray emissions can help them understand even more extreme objects in our universe. NuSTAR typically studies objects outside our solar system, such as exploding stars and disks of hot gas accelerated by the gravity of massive black holes.

The new study is the first example of scientists being able to compare NuSTAR observations with data taken at the source of the X-rays (by Juno). This enabled researchers to directly test their ideas about what creates these high-energy X-rays. Jupiter also shares a number of physical similarities with other magnetic objects in the universe – magnetars, neutron stars, and white dwarfs – but researchers don’t fully understand how particles are accelerated in these objects’ magnetospheres and emit high-energy radiation. By studying Jupiter, researchers may unveil details of distant sources we cannot yet visit.

Reference: “Observation and origin of non-thermal hard X-rays from Jupiter” by Kaya Mori, Charles Hailey, Gabriel Bridges, Shifra Mandel, Amani Garvin, Brian Grefenstette, William Dunn, Benjamin J. Hord, Graziella Branduardi-Raymont, John Clarke, Caitriona Jackman, Melania Nynka and Licia Ray, 10 February 2022, Nature Astronomy.
DOI: 10.1038/s41550-021-01594-8

More About the Missions

NuSTAR launched on June 13, 2012. A Small Explorer mission led by Caltech and managed by JPL for NASA’s Science Mission Directorate in Washington, it was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The telescope optics were built by Columbia University; NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and DTU. The spacecraft was built by Orbital Sciences Corp. in Dulles, Virginia. NuSTAR’s mission operations center is at the University of California, Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center. ASI provides the mission’s ground station and a mirror data archive. Caltech manages JPL for NASA.

JPL manages the Juno mission for the principal investigator, Scott J. Bolton of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space in Denver built and operates the spacecraft.

3 Comments on "NASA’s NuSTAR Spots Highest-Energy Light Ever Detected From Jupiter – And Solves a Decades-Old Mystery"

  1. This is amazing.I think it explains Tesla thought about energy in the air.

  2. Babu G. Ranganathan | February 12, 2022 at 8:04 am | Reply

    Babu G. Ranganathan*
    (B.A. Bible/Biology)

    JUST BECAUSE SCIENCE CAN EXPLAIN how an airplane works doesn’t mean that no one designed or made the airplane. And just because science can explain how life or the universe works doesn’t mean there was no Designer and Maker behind them.

    Natural laws may explain how the order in the universe works and operates, but mere undirected natural laws cannot explain the origin of that order. Once you have a complete and living cell then the genetic code and biological machinery exist to direct the formation of more cells from raw materials such as amino acids and other chemicals, but how could life or the cell have naturally originated when no directing code and mechanisms existed in nature? Read my Internet article: HOW FORENSIC SCIENCE REFUTES ATHEISM.

    WHAT IS SCIENCE? Science simply is knowledge based on observation. No human observed the universe coming by chance or by design, by creation or by evolution. These are positions of faith. The issue is which faith the scientific evidence best supports.

    SCIENCE SHOWS THAT THE UNIVERSE CANNOT BE ETERNAL because it could not have sustained itself eternally due to the law of entropy (increasing and irreversible net energy decay, even in an open system). Even a hypothetical oscillating universe could not continue to oscillate eternally! Einstein’s General Theory of Relativity shows that space, matter, and time all are physical and all had a beginning. Space even produces particles because it’s actually something, not nothing. What about the Higgs boson (the so-called “God Particle”)? The Higgs boson, even if it existed, would not have created mass from nothing, but rather it would have converted energy into mass. Einstein showed that all matter is some form of energy. Even time had a beginning! Time is not eternal.

    The law of entropy doesn’t allow the universe to be eternal. If the universe were eternal, everything, including time and space (which modern science has shown are as physical as mass or matter), would have become totally entropied by now and the entire universe would have ended in a uniform heat death a long, long time ago. The fact that this hasn’t happened already is powerful evidence for a beginning to the universe.

    Popular atheistic scientist Stephen Hawking admits that the universe had a beginning and came from nothing but he believes that nothing became something by a natural process yet to be discovered. That’s not rational thinking at all, and it also would be making the effect greater than its cause to say that nothing created something. The beginning had to be of supernatural origin because science teaches us from the First Law of Thermodynamics that natural laws and processes do not have the ability to bring something into existence from nothing.

    The supernatural origin of the universe cannot be proved by science but science points to a supernatural intelligence and power for the origin and order of the universe. Where did God come from? Obviously, unlike the universe, God’s nature doesn’t require a beginning.

    The disorder in the universe can be explained because of chance and random processes, but the order can be explained only because of intelligence and design.

    Gravity may explain how the order found in the precise and orderly courses of thousands of billions of stars is maintained, but gravity cannot explain the origin of that order.

    Some evolutionary astronomers believe that trillions of stars crashed into each other leaving surviving stars to find precise orderly orbits in space. Not only is this irrational, but if there was such a mass collision of stars then there would be a super mass residue of gas clouds in space to support this hypothesis. The present level of residue of gas clouds in space doesn’t support the magnitude of star deaths required for such a hypothesis. And, as already stated, the origin of stars cannot be explained by the Big Bang because of the reasons mentioned above. It’s one thing to say that stars may decay and die into random gas clouds, but it is totally different to say that gas clouds form into stars.

    Even the father of Chaos theory admitted that the “mechanisms” existing in the non-living world allow for only very rudimentary levels of order to arise spontaneously (by chance), but not the kind or level of order we find in the structures of DNA, RNA, and proteins. Yes, individual amino acids have been shown to come into existence by chance but not protein molecules which require that the various amino acids be in a precise sequence just like the letters found in a sentence.

    Some things don’t need experiment or scientific proof. In law there is a dictum called prima facie evidence. It means “evidence that speaks for itself.”

    An example of a true prima facie would be if you discovered an elaborate sand castle on the beach. You don’t have to experiment to know that it came by design and not by the chance forces of wind and water.

    If you discovered a romantic letter or message written in the sand, you don’t have to experiment to know that it was by design and not because a stick randomly carried by wind put it there. You naturally assume that an intelligent and rational being was responsible.

    It’s interesting that Carl Sagan would have acknowledged sequential radio signals in space as evidence of intelligent life sending them, but he wouldn’t acknowledge the sequential structure of molecules in DNA (the genetic code) as evidence of an intelligent Cause. Read my popular Internet article, HOW DID MY DNA MAKE ME.

    I encourage all to read my popular Internet articles:


    Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION (This site answers many arguments, both old and new, that have been used by evolutionists to support their theory)


    *I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

  3. Interesting.

    Some Thoughts.

    1. Figure out the Energy-Matter Equilibrium in Nature and how high energy and low energy energy matter is ccreated, and exists in Nature, and we may have a better understanding of these observations from Jupiter.

    2. Develop a comprehensive theoritical basis under various scenarios AND conditions, which may have an impact on the form of the energy-matter spectrum we are observing, with various levels of energy (Low-medium-High) in the the Energy -Matter -Spectrum, keeping in mind Nano Particle existence and Quantum Field theory and the known sub-atomic particles we have discovered and how the jigsaw puzzle fits together.

    3. Can Particles exhibit Wave Behaviour. YES! Have you heard about the fish which band together and exhibit wave like behavior, to avoid being gobbled up by the Winged Avian Progeny of Dinosaurs ? Is wave-particle real in light of Nano and Quantum?

    Views expressed arepersonal and not binding on anyone..

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