JUICE swings past Earth again
On 28 September 2026 ESA's Jupiter-bound JUICE spacecraft passed 8,640 km above Earth, using its gravity to gain about 3.5 km/s. It was the mission's third gravity assist; one more Earth flyby, in January 2029, sends it on to Jupiter in 2031.
The moment of JUICE swings past Earth again: https://nowsky.org/e/juice-earth-flyby-2026 — opens at the right place and time, replayable, no login.
Available views: Orbit ✓ · Sky — (not visible in the sky)
The story
At 11:45 UTC on 28 September 2026, ESA's Jupiter mission JUICE made its closest pass of Earth, 8,640 km above the Indian Ocean. That is about two-thirds of Earth's diameter, and more than twenty times higher than the International Space Station flies. During the brief encounter Earth's gravity bent the spacecraft's path, and it left with a new speed and a new direction.
The change was large. JUICE gained about 3.5 km/s, an extra 12,600 km per hour. Its path also turned by about 20 degrees. Producing that much change with the spacecraft's own engine would take a great deal of propellant. A gravity assist delivers it in exchange for one thing: arriving at exactly the right place at exactly the right time.
The spacecraft did not simply coast through. From 23 September to 3 October its team pointed several instruments at Earth and the Moon to collect calibration data. Measuring bodies whose properties are already well known is a way of checking that each instrument reports correct numbers. When JUICE later studies the icy moons of Jupiter, where nothing can be checked against a familiar answer, those checks will matter.
About eleven minutes after closest approach, at 11:56 UTC, the JMC1 monitoring camera photographed Earth falling away behind the spacecraft. The picture shows Africa and Madagascar, with the Moon reduced to a small dot. ESA followed it in October with a movie of the flyby. JUICE is now on a loop around the Sun that brings it back to Earth one final time in January 2029.
Mission goals
Flying straight to Jupiter would need a much bigger rocket and far more propellant. JUICE, which weighs about six tonnes, instead takes a longer route and collects speed a little at a time from the bodies it passes. Planets move quickly around the Sun, and a spacecraft that skims past one in the right direction borrows a share of that motion. The cost is time: the journey takes about eight years instead of a few.
This flyby was one link in a fixed chain. The combined Moon and Earth flyby of August 2024, the Venus flyby of 31 August 2025 and this second Earth pass have each stretched the orbit further. One more Earth flyby, in January 2029, completes the chain. Any error along the way would ripple forward into the planned July 2031 arrival at Jupiter, which is why the height and timing of each pass are controlled so carefully.
Gravity assists are not unique to JUICE. Most spacecraft bound for the outer planets, or for Mercury close to the Sun, rely on them. NASA's Europa Clipper, also headed for Jupiter, uses Mars and then Earth, while BepiColombo made repeated passes of Earth, Venus and Mercury to lose speed rather than gain it. This flyby is one more example of how precisely the technique can now be handled.
Mission chronology and background
JUICE, the JUpiter ICy moons Explorer, was launched on an Ariane 5 rocket from French Guiana on 14 April 2023. Its targets are Ganymede, Europa and Callisto, three large moons of Jupiter that scientists think hide oceans of liquid water beneath thick shells of ice. The spacecraft's instruments are designed to measure those ice shells and look for evidence of the water below.
The first big manoeuvre came in August 2024, when JUICE flew past the Moon and then, a day later, Earth, the first time a spacecraft had used the pair back to back. It passed Venus on 31 August 2025. With the 2026 Earth flyby also going to plan, the schedule remains intact: arrival at Jupiter in July 2031, many passes of its moons, and entry into orbit around Ganymede in December 2034.
Borrowing a planet's gravity to change course is a long-established technique. Mariner 10 used Venus to reach Mercury, and Voyagers 1 and 2 swung past Jupiter and Saturn on their way out of the solar system. The Jupiter orbiter Galileo, like JUICE, flew past Venus and Earth to get there. JUICE's back-to-back pass of the Moon and Earth built on that experience and took it a step further.
Other milestones of this mission
Where to see it — sky and simulator
In the orbit view, select JUICE as the tracked object and set the date to 28 September 2026. The replay shows the spacecraft skimming past Earth and its path bending outward. Speed up the clock and JUICE loops once around the Sun, returns to Earth for its final flyby in January 2029, and then heads out on the long arc towards Jupiter.
There was little to see in the actual sky. At closest approach the spacecraft was over the Indian Ocean, and it is far too small to pick out without help. The best record of the flyby is the JMC1 image and the movie released by ESA. The next time JUICE comes close to Earth will be its last visit, in January 2029.
See this for yourself — replay the moment in the orbit view
FAQ
Does a flyby slow Earth down?
In principle, yes. Whatever the spacecraft gains, Earth gives up. But Earth is so enormously more massive than a six-tonne probe that the change is far too small for any instrument to detect.
Why does JUICE pass Earth more than once?
One flyby can only add so much speed. JUICE therefore builds up its orbit in steps, Moon and Earth, then Venus, then Earth again, and the final Earth flyby in January 2029 gives it the speed it needs to reach Jupiter.
Did JUICE take pictures this time?
Yes. The JMC1 monitoring camera captured Earth at 11:56 UTC as the spacecraft moved away, showing Africa, Madagascar and the Moon as a small dot. ESA also released a movie of the flyby in October.
When does JUICE reach Jupiter?
After a final Earth flyby in January 2029, it is due at Jupiter in July 2031. It will then make repeated passes of the moons before entering orbit around Ganymede in December 2034.
Related
Times and figures are approximate — verify with official sources when planning travel. Simulation uses J2000 mean elements.