What is beneath the icy crusts of three of Jupiter’s moons?
Little attention has been paid to it so far, but in exactly one year everyone will be talking about JUICE – an exciting and unique mission to study Jupiter’s moons Europa, Callisto and Ganymede, which will put it in full orbit around the latter.
- Ganymede is the largest moon we know. It is larger than Mercury and Pluto. It has a magnetic field. It has an atmosphere. It may have an underground saltwater ocean.
- Europe is the smallest of the so-called Galilean moons of Jupiter, but one of the most exciting. It is also believed that beneath its frozen outer shell there is an ocean that may have existed since the formation of the solar system… long enough for life to take root.
- CallistoJupiter’s second largest moon, after Ganymede, has a dull, lifeless appearance – but it’s also now thought to have a subterranean ocean.
JUICE will find out for sure. This large-scale mission as part of the European Space Agency (ESA) program “Cosmic Vision”, short for JUpiter ICy moons Explorer, is scheduled to take off between April 5 and 25, 2023 with an Ariane 5 rocket from the European Spaceport in French Guiana , South America.
After a long journey to the Jupiter system, it will arrive in 2031 to be the first European spacecraft to visit Jupiter. It will then take three and a half years to examine the ice moons Ganymede, Europa and Callisto.
Its unique mission will view Europa and Callisto during flybys. It will also conduct flybys of Ganymede, but most importantly, it will also go into orbit in September 2032.
It will be the first spacecraft to orbit a moon other than Earth’s moon.
Ganymede is particularly interesting. A weird and wonderful place, Ganymede may look a bit like our moon, but that’s where the similarity ends. It’s actually covered with an ice crust, but scientists think it may have an underground ocean about 100 kilometers below.
Ganymede also has a magnetic field, which is an indication that it has an iron core surrounded by liquid metallic components, which – like on Earth – can create and maintain a magnetic field.
These will be the first close flybys of these moons since NASA’s Galileo mission in 1995-2003. However, in June 2021, NASA’s Juno spacecraft was able to get very close to Ganymede.
A year before JUICE arrives, NASA’s Europa Clipper mission will orbit Europa 32 times… so if you love icy moons, the next decade or two of space exploration is going to be very exciting.
I wish you clear skies and big eyes.