Europa Clipper reaches Jupiter
Europa Clipper, the largest spacecraft NASA has launched to another planet, is due to reach Jupiter in April 2030. From orbit around Jupiter it will fly past the moon Europa 49 times to study the ocean hidden beneath its thick ice.
Available views: Orbit ✓ · Sky — (not visible in the sky)
The story
Europa Clipper is the largest spacecraft NASA has ever sent towards another planet. It launched on a Falcon Heavy rocket on 14 October 2024 and, after a journey of about five and a half years, is due to reach Jupiter in April 2030. As its name suggests, it has one target: Jupiter's moon Europa. The aim of the whole mission is to find out whether an ocean really lies beneath Europa's shell of ice, and if so, what kind of ocean it is.
Unusually, the spacecraft will not orbit Europa. Instead it will make wide loops around Jupiter, passing close to Europa briefly on each loop. The reason is radiation. Near Jupiter, fast-moving particles pour down so strongly that a spacecraft staying close to Europa would soon have its electronics ruined. Swinging far out and then coming back in again stretches out the spacecraft's working life.
The observations therefore come from a long series of close flybys. Forty-nine are planned, and on the closest the spacecraft will pass just 25 km above the surface. Each flyby crosses a different area under different sunlight, so together they add up to a survey of the whole moon. The spacecraft carries nine science instruments, including radar that can see into the ice, a magnetometer to measure magnetic fields, cameras, and instruments that analyse dust and gas thrown up from the surface.
The huge solar panels are another feature. The sunlight that reaches Jupiter is only a few percent of what reaches Earth, so the wings had to be very large to make enough electricity. Fully opened, they span about 30.5 metres, longer than a basketball court. Follow the spacecraft in the orbit view and its route is reproduced: past Mars, back past Earth, and then out towards Jupiter.
Mission goals
What makes Europa special is the amount of water and where its heat comes from. The surface is ice, but scientists think there may be more liquid water beneath it than in all of Earth's oceans put together. The heat that keeps it liquid comes not from the Sun but from Jupiter. Europa's orbit is slightly stretched, so its distance from Jupiter keeps changing, and each time Jupiter's pull stretches and squeezes the moon, warming its interior. That is how water can stay liquid so far from the Sun.
When deciding whether a place could support life, scientists usually look for three things: liquid water, chemical energy that living things could use, and raw materials such as carbon. Europa very probably has the first, and the other two are what this mission sets out to investigate. If the ocean rests directly on rock, chemistry like that found at hot springs on Earth's deep sea floor could take place. The kinds of salts and compounds left on the surface offer clues to whether it does.
This is not a mission to detect life directly. Its goal is to measure whether the conditions for life are present: how thick the ice shell is, how deep and salty the ocean is, and whether material can travel between the surface and the water below. Only once those questions are answered can scientists decide what a search for life should look for, and how. That distinction is worth remembering when the results come in.
Mission chronology and background
The idea that Europa might have an ocean began with the Voyager spacecraft. Images sent back in 1979 showed a smooth ice world with almost no craters and covered in cracks. Few craters meant the surface was being renewed. In the 1990s the Galileo spacecraft found magnetic evidence of a layer beneath the ice that conducts electricity. Salty water conducts electricity well, so the idea of an ocean became a serious hypothesis.
After that, missions dedicated to Europa were proposed many times but kept being put off because of cost and the problem of surviving the strong radiation. The approach that solved both problems at once is the one now flying: orbit Jupiter and fly past Europa again and again. It took decades to get from the first idea to the 2024 launch.
What follows arrival happens in stages. After entering Jupiter orbit, the spacecraft spends a period adjusting its orbit before the Europa flybys begin, and over about four years it makes 49 of them. The mission is planned to end in September 2034. In the same period ESA's JUICE spacecraft, arriving at Jupiter in July 2031, will also be at work, and comparing the data from the two missions is likely to be a major thread of Jupiter science in the 2030s.
Other milestones of this mission
Where to see it — sky and simulator
The arrival at Jupiter is not something you can see, but the orbit view lets you follow the whole journey. The spacecraft swung past Mars on 1 March 2025 to change course, and it is due to swing past Earth on 3 December 2026 to gain more speed. In the orbit view, each of these passes is reproduced opening the orbit wider, until a final long leg stretches out to Jupiter.
What you can see in the night sky is the destination, Jupiter. When it is up, it shines very brightly with a steady white light that even a beginner can find easily. Hold binoculars steady and you will see up to four small points lined up on either side of the planet. These are the Galilean moons, and one of them is Europa. To tell which point is Europa, it is best to use a chart of the moons' positions for your observing time.
News of the mission comes from NASA and its Jet Propulsion Laboratory, which have released status reports and images at each important stage. Jupiter orbit insertion will be announced by the time the spacecraft's signal reaches Earth. Radio signals take tens of minutes to travel from Jupiter to Earth, so the announced time is later than the moment the event actually happened by that amount.
See this for yourself — replay the moment in the orbit view
FAQ
Does Europa Clipper orbit Europa?
No. It orbits Jupiter and makes 49 close flybys of Europa. The strong radiation near Jupiter would quickly damage its electronics if it stayed near Europa, so looping far out between flybys keeps it working longer.
Is this a mission to find life?
No. Its goal is to measure the conditions for life: the thickness of the ice shell, the depth and saltiness of the ocean, and whether material moves between the surface and the water below. Those answers are what a future life-detection mission would need to be designed well.
When does it reach Jupiter?
Arrival is planned for April 2030. After launching in October 2024 it flew past Mars in March 2025, and it is due to fly past Earth in December 2026 to gain more speed. Once at Jupiter it will adjust its orbit before the Europa flybys begin.
Can I see Europa in the sky?
With binoculars, yes. Europa is one of the four Galilean moons lined up beside Jupiter. It sits close to the planet's glare, so a chart of the moons' positions for your observing time helps. The spacecraft itself is far too small to see.
Related
- Europa Clipper launch (2024)
- Europa Clipper Earth flyby
- JUICE arrives at Jupiter
- Europa — object index
- Jupiter — object index
Times and figures are approximate — verify with official sources when planning travel. Simulation uses J2000 mean elements.