Key points
- Europa's subsurface ocean, heated by tidal forces and possibly harbouring thermal vents, may have the right conditions for life.
- The Europa Clipper spacecraft will take nearly six years to reach the moon, entering the Jupiter system in early 2030.
- The CSIRO-managed Canberra Deep Space Communication Complex will play a key role in the mission’s success.
Europa is Jupiter’s fourth largest moon. It is roughly the size of Earth’s Moon and orbits in an intense radiation zone.
The first close-up images of Europa were captured by the Pioneer and Voyager spacecraft more than 40 years ago. These images revealed Europa as an ice-encrusted world, scarred and cracked by criss-crossing ridges and large blocks of broken terrain.
Later missions found evidence that something interesting was happening underneath the surface.
Scientists believe a liquid water ocean 60-150 kilometres deep lies beneath a 15km-thick ice crust. Europa also has a magnetic field which suggests it has a liquid mantle like Earth.
The liquid ocean is possible due to heat generated by the moon being constantly stretched and squeezed as it orbits its giant host planet. Thermal vents may also occur on the ocean floor, similar to those found deep in Earth’s oceans. There’s also evidence of plumes of gas and water venting through Europa’s crust.
On the left is a view of Jupiter's moon Europa taken on March 2, 1979, by NASA's Voyager 1 spacecraft. In the middle is a color image of Europa taken by NASA's Voyager 2 spacecraft during its close encounter on July 9, 1979. On the right is a view of Europa made from images taken by NASA's Galileo spacecraft in the late 1990s.
A six-year bus ride to an icy moon
NASA’s Europa Clipper spacecraft is the largest NASA has ever built for a planetary mission. The spacecraft body is roughly the size of a bus and is powered by huge solar panels which stretch the length of a basketball court!
But this is no ordinary bus ride – Clipper will take six years to reach Jupiter. To conserve fuel, the spacecraft will make two slingshot manoeuvres, using the gravity of Mars and Earth to accelerate towards Jupiter.
Once it arrives in the Jupiter system in April 2030, Europa Clipper will fly by some of Jupiter's other large moons. It will then intersect with Europa's orbit in early 2031.
The spacecraft will make nearly 50 flybys of Europa, soaring over a different location during each encounter to scan nearly the entire moon. Its closest approach will be just 25 kilometres above the surface.
The detailed exploration of Europa will help scientists better understand if this tiny moon could support life.
Technicians examine the first of two fully extended five-panel solar arrays built for NASA’s Europa Clipper suspended on a support system called a gravity offload fixture during inspection and cleaning as part of assembly, test, and launch operations inside the Payload Hazardous Servicing Facility at the agency’s Kennedy Space Center in Florida on Wednesday, March 6, 2024. Another name for the gravity offload fixture is the Transportable Large Envelope Deployment Facility (T-LEDF). When both solar arrays are installed and deployed on Europa Clipper – the agency’s largest spacecraft ever developed for a planetary mission – the spacecraft will span a total length of more than 100 feet and weigh 7,145 pounds without the inclusion of propellants.
Phoning home
Our team in Canberra and our two sister Deep Space Network stations around the world in Spain and the United States will be with the mission every step of its 2.9 billion kilometre journey to Europa.
A crucial step in the mission is the 'acquisition of signal' or AOS. This occurs once the spacecraft separates from its launch vehicle. It's a crucial step which ensures we can communicate with the spacecraft and can check it survived the rigours of launch.
Our team at the Canberra Deep Space Communication Complex will help keep the spacecraft connected to the engineering and science teams who are eager to discover more about Europa.
Smile for the cameras!
The nine scientific instruments the spacecraft is carrying will photograph and measure the nature of Europa’s ice shell and the subsurface ocean. They will also analyse the moon’s composition and geology.
Clipper has five imagers onboard including three cameras – a wide-angle, a narrow-angle and a thermal imager. The wide and narrow angle cameras will capture high-resolution colour images of the moon’s surface. They will also produce stereoscopic images which will help scientists map the surface.
The thermal imager will map the surface temperature. Warmer areas may indicate that liquid water is nearer the surface. There’s also an infrared spectrometer on board which will map the composition helping scientists understand the distribution of materials on the moon.
The mission’s ultraviolet spectrograph will measure the composition of tiny particles in the moon's thin atmosphere. The particles are possibly being produced by geysers on its surface.
Other instruments like the ice-penetrating radar will search for subsurface water – mapping the ocean. And the magnetometer and gravity measurements will help scientists understand more about the ocean and moon's interior.
We’re wishing Clipper bon voyage and will make sure to keep the phone lines working for its amazing journey.