NASA's Europa Clipper Launched on 14 October 2024, Passes Earth on 3 December 2026 and Will Make 49 Close Flybys of Jupiter's Ocean Moon From 2031

Europa Clipper passes Earth on 3 December 2026 at a distance of about 3,200 kilometres (2,000 miles), according to NASA’s mission timeline. The pass is a gravity assist, a swing that borrows energy from the planet’s pull, and it is the last big course change before the spacecraft reaches Jupiter in April 2030 and starts 49 close flybys of the moon Europa.

NASA’s stated aim is to determine whether there are places below Europa’s surface that could support life. Its three objectives are the ice shell and the ocean beneath it, the moon’s composition, and its geology.

From Florida to Jupiter by way of Mars and Earth

The spacecraft lifted off at 12:06 p.m. EDT on 14 October 2024 on a SpaceX Falcon Heavy from Launch Complex 39A at Kennedy Space Center. NASA puts the whole trip at about 1.8 billion miles (2.9 billion kilometres).

The route is indirect on purpose. JPL says that without the Mars and Earth assists the spacecraft would need additional propellant. On 1 March 2025 it passed about 550 miles (884 kilometres) above Mars.

Engineers used that pass for a test JPL says was impossible to do on Earth. The ice-penetrating radar was switched on for about 40 minutes as the spacecraft dropped from roughly 5,000 kilometres to 884 kilometres above Mars, and it returned 6 gigabytes of data. Don Blankenship of the University of Texas at Austin, the radar’s principal investigator, said every part of the instrument did what was intended.

The Earth pass doubles as a calibration session. An abstract by Haje Korth, Robert Pappalardo and Bonnie Buratti says it will support an absolute calibration of the magnetometer against Earth’s magnetic field, and a cross-calibration of the plasma instrument against other spacecraft near Earth.

At Jupiter, NASA’s timeline describes an engine burn of about six hours to brake into orbit, with a flyby of Ganymede during the manoeuvre. The first Europa flyby comes in spring 2031. The spacecraft never orbits Europa. It loops widely around Jupiter and dives in, at altitudes as low as 16 miles (25 kilometres) above the surface. The timeline lists September 2034 as a possible end of mission, with a planned disposal into Ganymede.

What the Galileo magnetometer found

NASA says Europa shows strong evidence for an ocean of liquid water under its ice, holding about twice as much water as Earth’s global ocean. Nobody has sampled it, and the case for it was built from a distance.

The first strong evidence came from the magnetometer on NASA’s Galileo orbiter. In a Nature paper dated 22 October 1998, K. K. Khurana, Margaret Kivelson and five co-authors reported disturbances in Jupiter’s magnetic field near Europa and Callisto. They attributed them to magnetic fields induced in the moons, and concluded that the likeliest cause was a layer of significant electrical conductivity just under each surface, best explained by salty liquid water.

A second result followed. NASA reported on 25 August 2000, from a Science paper, that Jupiter’s field at Europa pointed the opposite way during a January 2000 flyby than in 1996 and 1998. The team’s model had predicted how a saltwater layer would respond to that reversal, and the data matched. NASA’s own release added a limit: “The evidence is still indirect and requires several steps of inference.”

How thick the ice on top is remains open. A Juno flyby on 29 September 2022, at about 360 kilometres, produced an estimate that JPL announced on 27 January 2026: about 18 miles (29 kilometres) on average in the region observed. Juno project scientist Steve Levin said that figure covers only the cold, rigid outer layer, and that a warmer layer beneath would add thickness, while dissolved salt in the ice would cut about 3 miles from the estimate.

The plume claims that weakened in May 2026

Water vapour venting from Europa would let a spacecraft sample the ocean without landing. The claim rests on Hubble Space Telescope work by two teams.

A 2014 paper led by Lorenz Roth reported ultraviolet emission over Europa’s southern hemisphere that it attributed to plumes. In 2016 a team led by William Sparks of the Space Telescope Science Institute saw possible plumes in 3 of 10 Hubble images of Europa crossing Jupiter’s face, over 15 months. NASA’s release estimated a height of about 125 miles (200 kilometres) and noted that the two teams had not detected plumes at the same time. NASA’s Geoff Yoder said such plumes, “if they do indeed exist,” could offer another way to sample the subsurface.

On 18 May 2026 Southwest Research Institute reported a reanalysis of 14 years of Hubble spectrograph data, published in Astronomy & Astrophysics. Roth, the lead author, said the team’s original 99.9 percent confidence in the plumes dropped to less than 90 percent. The new data neither confirm the 2014 plumes nor rule them out. SwRI’s release says Clipper, arriving in 2030, may investigate.

Nine instruments and a radio experiment

NASA lists nine science instruments plus a gravity and radio science experiment that uses the spacecraft’s communications system.

• REASON (Radar for Europa Assessment and Sounding: Ocean to Near-surface) is the ice-penetrating radar. It is meant to see inside the ice shell for pockets of water and may detect the ocean under it. A different NASA radar, on an Earth-watching satellite built with ISRO, is covered in the NISAR article.
• ECM (Europa Clipper Magnetometer) measures the magnetic field to confirm the ocean and estimate its depth and salinity. Its sensors sit on a boom 28 feet (8.5 metres) long.
• PIMS (Plasma Instrument for Magnetic Sounding) measures the plasma around Europa so its distortions can be separated from the field the ocean induces.
• MASPEX (MAss Spectrometer for Planetary EXploration/Europa) analyses gases in Europa’s faint atmosphere and any plumes.
• SUDA (SUrface Dust Analyzer) identifies the chemistry of dust grains thrown off the moon, which may carry clues to the ocean’s salinity.
• EIS (Europa Imaging System) has wide-angle and narrow-angle cameras, each with an eight-megapixel sensor, for colour and stereo images.
• E-THEMIS (Europa Thermal Emission Imaging System) maps heat to find warmer spots where water may be near the surface or has erupted.
• Europa-UVS (Europa Ultraviolet Spectrograph) reads ultraviolet light to identify gases and surface materials and to look for plumes.
• MISE (Mapping Imaging Spectrometer for Europa) is an infrared spectrometer that maps ices, salts and organic compounds.
• Gravity and radio science tracks tiny shifts in the spacecraft’s radio signal to measure how Europa flexes as it orbits Jupiter.

Power comes from two solar arrays of five panels each, about 14.2 by 4.1 metres apiece, spanning more than 30.5 metres. The press kit says they supply at least 700 watts through the prime mission.

A vault against Jupiter’s radiation

JPL says Jupiter’s magnetic field is 20,000 times stronger than Earth’s and that its radiation is the most intense in the solar system apart from the Sun. The electronics that run the science instruments, guidance and thermal pumps sit inside a vault bolted to the propulsion module.

NASA’s pages describe the walls differently. A JPL feature of October 2023 calls the vault aluminium just under half an inch (1 centimetre) thick and says it was sealed on 7 October 2023. The press kit gives aluminium-zinc alloy sheets up to 9.2 millimetres thick, and the mission overview says titanium and aluminium. None of those pages gives a radiation dose figure. JPL’s own wording is that the vault should reduce the radiation to acceptable levels for most of the electronics.

Juice, the European companion

The European Space Agency’s Jupiter Icy Moons Explorer, Juice, launched on 14 April 2023 on an Ariane 5 from Europe’s Spaceport in French Guiana, the same type of rocket and launch site used for the James Webb Space Telescope. ESA plans Jupiter orbit insertion for 20 July 2031, a year after Clipper. Juice carries ten instruments and is the first spacecraft intended to orbit Ganymede.

Juice flew past Earth on 28 September 2026, passing 8,640 kilometres above the Indian Ocean at 11:45 UTC. ESA says that bent its path by 20 degrees and added 3.5 kilometres per second to its speed. A last Earth flyby follows in January 2029.

Juice’s Europa work is brief next to Clipper’s 49 passes. ESA’s tour table lists two flybys, on 2 July 2032 and 16 July 2032, each with a closest approach of 401 kilometres.