February 28, 2022Great Explorations Revisited: The 2007 Flyby of Jupiter

On discoveries alone, the flyby of NASA‘s New Horizons past Jupiter on February 28, 2007, was a successful mission in its own right. While the Pluto-bound spacecraft was zooming past the giant planet for a gravity boost toward its main targets in the distant reaches of the solar system, and testing out its science instruments just a year after launch, New Horizons revealed the Jovian system in ways never seen before.

New Horizons was actually the eighth spacecraft to visit Jupiter. But its path past the giant planet – along with a sophisticated instrument payload and some great timing -- allowed it to explore exciting new details of the Jupiter system: lightning near the planet's poles; the life cycle of fresh ammonia clouds; boulder-size clumps racing through the planet's faint rings; a developing storm tagged the Little Red Spot; the structure inside volcanic eruptions on the moon Io; and charged-particle clumps traversing the length of Jupiter's magnetic tail that New Horizons was the first to reconnoiter.

In the 15 years since that flyby, results from New Horizons’ Jupiter exploration have appeared in dozens of research papers and widespread conference presentations -- starting with a special issue of the prestigious journal Science in October 2007.

The technology onboard the New Horizons spacecraft also evolved into a new series of remote-exploration tools. Next-gen versions of the Alice ultraviolet spectrometer, which probed Jupiter’s atmosphere for data on cloud structure and composition, are set to return to the solar system’s largest planet on NASA’s Europa Clipper and the European Space Agency’s Jupiter Icy moons Explorer (JUICE) missions. NASA’s Lucy asteroid mission is carrying a new version of the Ralph color imager, and new instruments based on Long Range Reconnaissance Imager (LORRI), the telescopic camera that spied Io’s Tvashtar volcano in mid-eruption, among other amazing sights, are flying on Lucy as well as NASA’s Double Asteroid Redirection Test (DART) mission.

“LORRI was optimized for observing the Pluto system, where sunlight is about 45 times fainter than in the Jovian system,” said Hal Weaver, the New Horizons project scientist and LORRI principal investigator from the Johns Hopkins Applied Physics Laboratory. “So we were thrilled to discover that, by keeping exposure times to just a few milliseconds, we could capture beautiful images of Jupiter and its moons without saturating the camera.”

New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, said the Jupiter flyby far exceeded the mission team’s expectations.

"Not only did the Jupiter encounter prove out our spacecraft and put us on course to explore Pluto in 2015,” he said, “it was a chance for us to take sophisticated instruments to places in the Jovian system where other spacecraft hadn’t gone, to pioneer some of the science that NASA’s Juno mission is now undertaking at Jupiter, and to return important data that added tremendously to our understanding of the solar system's largest planet and its moons, rings and atmosphere."

Read more about New Horizons’ historic Jupiter encounter.

Montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the New Horizons spacecraft's Jupiter flyby in early 2007. This image appeared on the cover of Science in October 2007.

At just before noon EST on Feb. 28, 2007, (from left) New Horizons science team co-investigators Jeff Moore and John Spencer, NASA Program Scientist Denis Bogan, Project Scientist Hal Weaver, Principal Investigator Alan Stern and Mission Operations Manager Alice Bowman applaud upon confirming the New Horizons spacecraft’s successful Jupiter flyby in the New Horizons Mission Operations Center at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.