- The JUICE probe will take off this Thursday, April 13 from Kourou
- In 2031 it will arrive around Jupiter and its Moons
- Ganymede, Europe and Callisto have an ocean of liquid water, and therefore life?
This Thursday, April 13, at 2 p.m. (French time), an Ariane 5 rocket is due to launch from Kourou in French Guiana. Under the fairing of the rocket, the JUICE probe, heavy of a few tons but which carries with it all the hopes of the old continent.
With this mission, Europe wants to regain its status as a pioneer in space exploration. ESA hopes to reach Jupiter and its Moons, 600 million kilometers from Earth. A one-of-a-kind journey to Europa, Ganymede and Callisto three candidates for hosting life in the solar system.
With JUICE, Europe wants to make history
Covered in a thick layer of ice these moons feature oceans below the surface. In these immense expanses of liquid water, life could very well have developed. In any case, this is what JUICE will seek to demonstrate during its mission which should end in 2035.
Over the next 20 years, the probe will therefore travel millions of kilometers in search of life. Before deploying its 10 scientific instruments, ESA must already succeed in reaching Jupiter. To get to the gas giant as quickly as possible, the laws of gravity require detours.
The ESA has notably planned to pass close to the Earth and Venus in order to “gain momentum” before launching towards Jupiter and its Moons. JUICE will then become the first European probe to cross the asteroid belt and venture so far from Earth. A titanic journey that should last 8 years.
In space, the fastest road is never straight, it is better to use the attraction of the planets to gain momentum © CNES
Ganymede: the “true” heart of the mission?
Once placed around Jupiter, the probe will focus on Ganymede, Europa and Callisto three of Jupiter’s moons. Their study must make it possible to answer one of the fundamental questions of the human species “Are we alone in the Universe?” If the probabilities tend to show no, no direct proof of the presence of extraterrestrials has been discovered to date.
In order to find out if our solar system is home to life elsewhere than on Earth, Europe is therefore setting out to conquer the Galilean moons that orbit around Jupiter. The ESA is betting in particular on Ganymede. With its large subglacial ocean, it is the favorite of this mission.
This Moon has the particularity of having a magnetic field, a prerequisite in many simulations to allow life to develop. Thanks to this magnetic field, Ganymede is protected on its surface from the most dangerous rays of the Sun. By way of comparison, if the Earth were to lose its magnetic field, life would disappear in just a few years.
The icy continent of the moon Europa seen by NASA’s Galileo probe © NASA / JPL / DLR
Europe and Callisto: the outsiders
Another candidate with strong potential, Europe. This moon also has a subglacial ocean. If its depth seems less important than on Ganymede it could be enough to allow life to form. Europe also benefits from an oxygen-rich atmosphere. However, its surface temperature (-186°C on average) makes outdoor life very complicated.
Finally, Callisto is the big rib of this mission. Its surface is the most heavily cratered in the entire solar system. Not really an advantage to allow time for life to develop. Very close to Jupiter, the moon is nevertheless protected by the very powerful magnetic field of the latter. In the shadow of its large neighbour, Callisto could well shelter primitive forms of life. JUICE intends in any case to put an end to the mystery.
The Jovian system: a world to discover
Going around Jupiter is not a trivial mission, but for a space agency like ESA. In the past, only NASA with its Galileo probe was interested in this remote region of the solar system. Arriving there in 1995, she notably discovered the subglacial oceans of Ganymede and Europe.
It was precisely this discovery that led Europe to launch the JUICE programme. In 2009 NASA originally wanted to follow up on Galileo in a joint mission with the Old Continent. But quickly the American space agency will abandon the project.
Rather than giving up, Europe dared to carry this great project alone. With an estimated cost of around 1.5 billion dollars, JUICE is a very substantial investment for ESA. As a reminder, the agency’s annual budget is 7 billion euros. This mission is to date the most ambitious and one of the most expensive in the history of the European Space Agency.
