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Could we discover the conditions necessary for life outside Earth in the solar system?
This is one of the mysteries that the space mission JUICE (For Jupiter ICy moons Explorer) – launched from Kourou, French Guiana, Thursday, April 13, 2023 at 12:14 p.m. Utah – will seek to elucidate.
To propel this mission to a planet more than 600 million kilometers away, the European Space Agency (ESA) brought together no less than 13 European countries, as well as the United States, Japan and Israel.
Through this mission, the agency also achieved the feat of placing JUICE on the launch pad only 11 years after the project greenlit. While the COVID pandemic slowed down the process, the delay was only nine months.
The France team, of which I am a part, too helped to develop six of JUICE’s ten advanced scientific instruments. The probe is expected to arrive in the Jovian system in 2031.
Pushing the frontiers of science
Jupiter is both the largest planet in our solar system and the one with the most moons. To date, estimates of their number vary between 82 and 95most of which have been discovered in the past two decades.
JUICE is the first mission to receive more than €1 billion in funding under ESA Cosmic vision program. It seeks to answer four main questions:
- How do planets form and life emerge?
- How does the solar system work?
- What are the fundamental laws of physics in the Universe?
- How did the current Universe come into being and what is it made of?
JUICE was chosen ahead of other proposed missions because it was designed to answer the first and last of these questions.
THE The Hubble Space Telescope and NASA space probes Traveler, Galileo, Juno have already picked up some clues either by direct observation or by deduction.
“Oceanic moons” containing more water than Earth
NASA’s Galileo was the first to discover water on the moons in 1995. Data captured by the space probe revealed gigantic liquid oceans not only beneath the crusts of its three icy moons, Callisto, Europa and Ganymede, but also on its volcanic moon, Io.
In 2014, the Hubble Space Telescope discovered geysers in Europe. Their bases seemed covered with salts, including carbonates. It is therefore likely that Europe can meet the four criteria for habitability:
- The famous quartet of carbon, hydrogen, oxygen, nitrogen (CHON), symbols of the main chemical elements that make up living beings.
- Liquid water that acts as a solvent.
- The energy to enable the development of life.
- A stable environment (orbits, rotation, average temperatures, etc.)
Galilean moons additionally take advantage of Jupiter’s gravitational energy, creating significant tidal effects and allowing the last two conditions above to be met.
Why Ganymed is the main focus
Ganymed should be studied much more thoroughly by JUICE than Callisto and Europa. This is not only because it is the largest moon in the solar system, but also an oceanic moon with its own magnetic field.

Similar to Earth’s magnetosphere, that of Ganymede has the potential to protect life by diverting the flow of cosmic rays and radiative particles from Jupiter. radiation belts.
JUICE, an extreme probe
JUICE’s route to the Jovian system will not follow a straight line. Instead, the spacecraft will fly over four different planets and moons which will alter and speed up its trajectory, also allowing it to save fuel – a trick also known as gravity assist maneuver.

Along the way, JUICE will have to deal with the highest levels of radiation in the solar system. This means that its electronic modules must be housed in lead-shielded cavities and components must be “hardened” to help them withstand the harsh environment.
JUICE will also have to deal with extreme temperatures, ranging from +250°C in flight Venus at -230°C in the Jovian system. To maintain a stable internal temperature, the spacecraft was covered with a multi-layer thermal insulation aluminum alloy and gray silicon, which earned the probe the nickname “silver beauty”.
An energy problem
Around Jupiter, which is five times farther from the Sun than Earth, the satellite will receive 25 times less solar energy than around Earth. The spacecraft does not carry radioactive battery because Europe is not yet capable of producing them industrially, unlike UNITED STATESRussia and China.
To enable the equipment and instruments to operate with 1000W (the power of a small hair dryer), the craft will rely on huge solar panels – their surface area totals 85m2 – which have been tested to withstand variations in radiation and temperature.
Built by 80 European companies under the direction of EADS Toulouse, the JUICE probe has a wingspan of 28 meters (the length of a basketball court), a communication antenna 2.5 meters long (required due to the distance from Jupiter to Earth).
It weighs nearly 6 tons on takeoff (most of which is propellant that will be consumed during the probe’s maneuvers) and carries around ten instruments (in all less than 280 kg).
Ten scientific instruments on board
Among these instruments, France – with the help of Italy – mainly designed the Moons and Jupiter Imaging Spectrometer (MAJIS). It is the instrument that will allow the spacecraft to determine the physico-chemical compositions of the surfaces of the moons during its flyby and thus to detect the CHON associated with potential habitability.
MAJIS will also study their ice caps and liquid waters. This will allow us to identify landing sites for future in situ exploration and to assess the structure and dynamics of Jupiter’s atmosphere.
With a precision 10,000 times greater than that of the equivalent instrument on Galileo, the spatial resolution of MAJIS is between 100 meters and several kilometers depending on the altitude of the probe at that moment.
Finally, it should be noted that JUICE’s plans could be revised depending on the latest results from NASA’s Juno mission. Juno is still orbiting Jupiter and has been flying past its poles since 2016.
Juno’s nominal mission has been extended to fly past each of Jupiter’s Galilean moons, starting with Ganymede in June 2021 and Europa in early 2023. These observations and subsequent data analysis will allow JUICE scientists to better target observations. they do – 12 years after Juno and 30 years after Galileo.
Watch the launch via ESA’s launch live stream below, starting at 7:45 a.m. EDT (11:45 a.m. GMT) on Thursday, April 13.
https://www.youtube.com/watch?v=fy-5xNs8FMI frameborder=”0″ allow=”accelerometer; automatic reading; clipboard-write; encrypted medium; gyroscope; picture in picture; web sharing” allowed in full screen >
The French laboratories involved in the development of JUICE are IAS, LABORATORY, LATMOS, IPAG, BET, LERMA, LESIA, LPC2EAnd BVG.
Carole LarigauderieDeputy Deputy Director of Projects in the Sciences of the Universe and Project Manager of French contributions to JUICE, National Center for Space Studies (CNES)
This article is republished from The conversation under Creative Commons license. Read it original article.