Using cameras designed for navigation, scientists count ‘fireflies’ to determine the amount of radiation the spacecraft receives during each orbit of Jupiter.
Scientists with NASA’s Juno mission have developed the first complete 3D radiation map of the Jupiter system.
“This is the first detailed radiation map of the region at these higher energies, which is a major step in understanding how Jupiter’s radiation environment works.
The cameras record “hard radiation,” or ionizing radiation that impacts a spacecraft with sufficient energy to pass through the ASC’s shielding.
ASC data suggests that there is more very high-energy radiation relative to lower-energy radiation near Europa’s orbit than previously thought.
Jovian radiation data is not the ASC’s first scientific contribution to the mission.
Even before arriving at Jupiter, ASC data was used to determine a measurement of interstellar dust impacting Juno.
Dust Rings Like Juno’s ASC, the SRU has been used as a radiation detector and a low-light imager.
Scientists count “fireflies” with the help of navigational cameras to measure the radiation that the spacecraft encounters during each orbit around Jupiter.
A 3D map of the Jupiter system’s radiation has been created by scientists working on NASA’s Juno mission. In addition to describing the strength of high-energy particles in the vicinity of the icy moon Europa’s orbit, the map illustrates how the smaller moons orbiting close to Jupiter’s rings shape the radiation environment.
The Advanced Stellar Compass (ASC) on board Juno, which was designed and constructed by the Technical University of Denmark, and the Stellar Reference Unit (SRU) on board the spacecraft, which was manufactured by Leonardo SpA in Florence, Italy, are the sources of data used in this work. The complementary nature of the two datasets enables Juno scientists to characterize the radiation environment at various energies.
Low-light cameras like the ASC and SRU are made to help with deep-space navigation. Nearly every spacecraft has one of these kinds of instruments. Yet Juno’s scientific team had to take a completely different approach to the cameras in order to get them to function as radiation detectors.
According to Scott Bolton, principal investigator for Juno from the Southwest Research Institute in San Antonio, “we try to innovate new ways to use our sensors to learn about nature, and we have used many of our science instruments in ways they were not designed for.”. This represents a significant advancement in our knowledge of Jupiter’s radiation environment as it is the first comprehensive radiation map of the area at these higher energies. Planning observations for the upcoming generation of missions to the Jovian system will benefit from this. “.
The Firefly Count.
The goal of Juno’s ASC is to take pictures of stars using its four star cameras on the magnetometer boom of the spacecraft. This is done in order to determine the spacecraft’s orientation in space, which is essential for the success of the mission’s magnetic field experiment. However, the device has also shown itself to be a useful tool for detecting high-energy particle fluxes in Jupiter’s magnetosphere. The ionizing radiation that strikes a spacecraft with enough energy to get past the ASC’s shielding is captured by the cameras as “hard radiation.”.
According to Technical University of Denmark scientist John Leif Jørgensen, a Juno scientist, “the ASC takes an image of the stars every quarter-second.”. “In our images, a telltale signature resembling the trail of a firefly is left by extremely energetic electrons that breach its shielding. We can accurately calculate the amount of radiation because the instrument is set up to count the number of these fireflies. “.
The spacecraft has traveled through almost every area of space close to Jupiter due to Juno’s constantly shifting orbit.
More very high-energy radiation than lower-energy radiation may be present closer to Europa’s orbit than previously believed, according to ASC data. Additionally, the data validates that the side of Europa facing its orbital direction of motion has a higher concentration of high-energy electrons than the trailing side of the moon.. This is due to the fact that, as a result of Jupiter’s rotation, the majority of the electrons in its magnetosphere pass Europa from behind, but the extremely high-energy electrons drift backward and collide with Europa’s front side rather than swimming upstream like fish.
The ASC has contributed other scientific data to the mission besides Jovian radiation. ASC data was utilized to measure the amount of interstellar dust affecting Juno even before it arrived at Jupiter. The same dust-detection method that the imager used to identify tiny pieces of the spacecraft ejected by microscopic dust impacting Juno at high velocity was also used to identify a comet that had never been seen before.
Dust Mounds.
The SRU has served as a low-light imager and a radiation detector, much like Juno’s ASC. Data from both instruments suggest that the small “shepherd moons” that orbit within or near the edge of Jupiter’s rings (and contribute to the preservation of the rings’ shape) appear to interact with the planet’s radiation environment, just like Europa does. Both the ASC and SRU radiation counts sharply decrease when the spacecraft passes over magnetic field lines that are linked to ring moons or areas of dense dust. Additionally, the SRU is gathering uncommon low-light photos of the rings taken from Juno’s special position.
Lead co-investigator Heidi Becker, a scientist at NASA’s Jet Propulsion Laboratory in Southern California, which oversees the mission, stated, “There is still a lot of mystery about how Jupiter’s rings were formed, and very few images have been collected by prior spacecraft.”. Occasionally, we’re fortunate enough to get a picture of one of the tiny shepherd moons. Thanks to these pictures, we can see the distribution of dust in relation to the ring moons’ distance from Jupiter and determine the exact location of the moons right now. “.
More About the Mission.
For the benefit of the lead scientist, Scott Bolton of the Southwest Research Institute in San Antonio, NASA’s Jet Propulsion Laboratory, a branch of Caltech located in Pasadena, California, oversees the Juno project. At NASA’s Marshall Space Flight Center in Huntsville, Alabama, the Science Mission Directorate in Washington oversees the agency’s New Frontiers Program, of which Juno is a component. The Advanced Stellar Compass is the creation of the Technical University of Denmark. In Florence, Italy, Leonardo SpA constructed the Stellar Reference Unit. The spacecraft is built and operated by Denver-based Lockheed Martin Space.
You can get more details about Juno at:.
News Media Contact Details.
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Air Force Research Laboratory, Pasadena, California.
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NASA Headquarters, Washington DC.
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Toft, Simon Koefoed.
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+1-45-9137-0088.
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Deb Schmid.
Southwest Institute of Research, located in San Antonio.
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