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NASA's Juno Mission Halfway to Jupiter Science

Dec. 12, 2018

A south tropical disturbance has just passed Jupiter's iconic Great Red Spot, and is captured stealing threads of orange haze from the Great Red Spot in this series of color-enhanced images from NASA's Juno spacecraft. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt/Sean Doran › Full image and caption

NASA's Juno spacecraft captured this stunning Jovian cloudscape at 5:38 a.m. PST (8:38 a.m. EST) on Feb. 7, 2018, as the spacecraft performed its 11th close flyby of Jupiter. Citizen scientist Kevin M. Gill created this color-enhanced image using data from the spacecraft's JunoCam imager. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill › Full image and caption

Jupiter's northern circumpolar cyclones are captured in this color-enhanced image from NASA's Juno spacecraft. The image was taken at 5:42 p.m. PDT (8:42 p.m. EDT) on Sept. 6, 2018, as the spacecraft performed its 15th close flyby of Jupiter. Citizen scientist Gerald Eichstadt created this image using data from the spacecraft's JunoCam imager. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt › Full image and caption

This image was taken at 7:21 p.m. PDT (10:21 p.m. EDT) on Sept. 6, 2018, as the spacecraft performed its 15th close flyby of Jupiter. The version of the image on the left side shows Jupiter in approximate true color, while the same image on the right has been processed to bring out detail close to the terminator and reveals four of the five southern circumpolar cyclones plus the cyclone in the center. Citizen scientist Bjorn Jonsson created this image using data from the spacecraft's JunoCam imager. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Bjorn Jonsson › Full image and caption

This mosaic combines color-enhanced images taken over Jupiter's north pole when the lighting was excellent for detecting high bands of haze. The images were taken in the final hours of Juno's perijove 12 approach on April 1, 2018. Citizen scientists Gerald Eichstadt and John Rogers created this image using data from the spacecraft's JunoCam imager. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt/John Rogers › Full image and caption

A multitude of bright white "pop-up" storms in this Jupiter cloudscape appear in this image from NASA's Juno spacecraft. This color-enhanced image was taken at 1:55 p.m. PDT (4:55 p.m. EDT) on Oct. 29, 2018, as the spacecraft performed its 16th close flyby of Jupiter. Citizen scientists Gerald Eichstadt and Sean Doran created this image using data from the spacecraft's JunoCam imager. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt/Sean Doran › Full image and caption

Upcoming 16th science pass of Jupiter marks Juno's halfway point in prime mission data collection.

On Dec. 21, at 8:49:48 a.m. PST (11:49:48 a.m. EST) NASA's Juno spacecraft will be 3,140 miles (5,053 kilometers) above Jupiter's cloud tops and hurtling by at a healthy clip of 128,802 mph (207,287 kilometers per hour). This will be the 16^th science pass of the gas giant and will mark the solar-powered spacecraft's halfway point in data collection during its prime mission.

Juno is in a highly-elliptical 53-day orbit around Jupiter. Each orbit includes a close passage over the planet's cloud deck, where it flies a ground track that extends from Jupiter's north pole to its south pole.

"With our 16^th science flyby, we will have complete global coverage of Jupiter, albeit at coarse resolution, with polar passes separated by 22.5 degrees of longitude," said Jack Connerney, Juno deputy principal investigator from the Space Research Corporation in Annapolis, Maryland. "Over the second half of our prime mission - science flybys 17 through 32 - we will split the difference, flying exactly halfway between each previous orbit. This will provide coverage of the planet every 11.25 degrees of longitude, providing a more detailed picture of what makes the whole of Jupiter tick."

Launched on Aug. 5, 2011, from Cape Canaveral, Florida, the spacecraft entered orbit around Jupiter on July 4, 2016. Its science collection began in earnest on the Aug. 27, 2016, flyby. During these flybys, Juno's suite of sensitive science instruments probes beneath the planet's obscuring cloud cover and studies Jupiter's auroras to learn more about the planet's origins, interior structure, atmosphere and magnetosphere.

"We have already rewritten the textbooks on how Jupiter's atmosphere works, and on the complexity and asymmetry of its magnetic field," said Scott Bolton, principal investigator of Juno, from the Southwest Research Institute in San Antonio. "The second half should provide the detail that we can use to refine our understanding of the depth of Jupiter's zonal winds, the generation of its magnetic field, and the structure and evolution of its interior."

Two instruments aboard Juno, the Stellar Reference Unit and JunoCam, have proven to be useful not only for their intended purposes, but also for science data collection. The Stellar Reference Unit (SRU) was designed to collect engineering data used for navigation and attitude determination, so the scientists were pleased to find that it has scientific uses as well.

"We always knew the SRU had a vital engineering job to do for Juno," said Heidi Becker, Juno's radiation monitoring investigation lead at NASA's Jet Propulsion Laboratory in Pasadena, California. "But after making scientific discoveries in Jupiter's radiation belts and taking a first-of-its-kind image of Jupiter's ring, we realized the added value of the data. There is serious scientific interest in what the SRU can tell us about Jupiter."

The JunoCam imager was conceived as an outreach instrument to bring the excitement and beauty of Jupiter exploration to the public.

"While originally envisioned solely as an outreach instrument to help tell the Juno story, JunoCam has become much more than that," said Candy Hansen, Juno co-investigator at the Planetary Science Institute in Tucson, Arizona. "Our time-lapse sequences of images over the poles allow us to study the dynamics of Jupiter's unique circumpolar cyclones and to image high-altitude hazes. We are also using JunoCam to study the structure of the Great Red Spot and its interaction with its surroundings."

The SRU and JunoCam teams both now have several peer-reviewed science papers -either published or in the works - to their credit.

NASA's JPL manages the Juno mission for the principal investigator, Scott 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 NASA's Science Mission Directorate. The Italian Space Agency (ASI) contributed two instruments, a Ka-band frequency translator (KaT) and the Jovian Infrared Auroral Mapper (JIRAM). Lockheed Martin Space in Denver built the spacecraft.

More information about Juno is available at:

https://www.nasa.gov/juno

https://www.missionjuno.swri.edu

More information on Jupiter is at:

https://www.nasa.gov/jupiter

The public can follow the mission on Facebook and Twitter at:

https://www.facebook.com/NASAJuno

https://www.twitter.com/NASAJuno