Three of Jupiter’s largest moons—Io, Europa and Ganymede—will be visited by NASA’s Juno probe currently in the Jupiter system after its imminent “death dive” was postponed for four years.
Last week it was reported that Juno witnessed an asteroid or comet slam into Jupiter and disintegrate in its atmosphere.
Previously planned to plunge into Jupiter’s clouds after completing its 35th and final orbit on July 30, 2021, Juno’s extended mission will see it perform close flybys of the three moons through 2025.
In orbit of Jupiter since July 4, 2016, the 66 x 15 ft. spacecraft has just completed its 32nd perijove (close flyby) of the giant planet and returned a stack of incredible new images.
Juno’s extended mission will see it orbit Jupiter a further 42 times, during which it will perform close flybys of Jupiter’s north polar cyclones, Ganymede, Europa and Io.
It will also conduct the first extensive exploration of the faint rings encircling Jupiter. Photographed by Voyager 1 in 1979 and by the Galileo orbiter in the 1990s, the Jovian ring system largely dust from two of its smaller moons, Amalthea and Thebe.
MORE FOR YOU
“Since its first orbit in 2016, Juno has delivered one revelation after another about the inner workings of this massive gas giant,” said principal investigator Scott Bolton of the Southwest Research Institute in San Antonio. “With the extended mission, we will answer fundamental questions that arose during Juno’s prime mission while reaching beyond the planet to explore Jupiter’s ring system and Galilean satellites.”
Part of NASA’s New Frontiers program of medium-sized planetary science spacecraft, Juno is a flagship mission that will now move from a mission focused on studying the giant planet’s gravity and magnetic fields to a full system-explorer.
Here’s what Juno is going to do and when during its extended mission phase:
- Flyby of Ganymede within 600 miles/1,000 km—June 7, 2021.
- Flyby of Europa within 200 miles/320 km—September 29, 2022.
- Flybys of Io within 900 miles/1,500 km—December 30, 2023 and February 3, 2024.
- End of mission—September 2025.
“The mission designers have done an amazing job crafting an extended mission that conserves the mission’s single most valuable onboard resource—fuel,” said Ed Hirst, the Juno project manager at JPL. “Gravity assists from multiple satellite flybys steer our spacecraft through the Jovian system while providing a wealth of science opportunities.”
However, Juno will only escape death for so long.
Come September 2025—with nowhere near enough fuel to escape Jupiter’s gravity and so continue on a journey through the cosmos—its orbit will rapidly decay until it enters Jupiter’s upper atmosphere, heats-up and burns.
Such a “death plunge” is necessary because an off-course Juno could theoretically crash into one of Jupiter’s moons and contaminate it with the environment with microbes from Earth.
Those moons are precisely what Juno’s extended mission is designed to study.
The data Juno collects during its extended mission will also help NASA and ESA (European Space Agency) plan their next two (and possibly three) missions to Jupiter and its moons:
China has also been discussing two missions to the Jovian system— a Jupiter Callisto Orbiter (JCO) and a Jupiter System Observer (JSO), one of which could launch in 2030 and arrive in 2036. It could include a landing on Jupiter’s small moon Callisto.
Wishing you clear skies and wide eyes.