Jupiter Icy Moons Explorer facts for kids

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Jupiter Icy Moons Explorer
Spacecraft properties
Artist's impression of the JUICE spacecraft The file above's purpose is being discussed and/or is being considered for deletion. See files for discussion to help reach a consensus on what to do.
Names	JUICE

Mission type	Planetary science
Operator	ESA
Mission duration	Cruise phase: 8 years Science phase: 3.5 years Elapsed: 2 years, 2 months and 3 days


Manufacturer	Airbus Defence and Space
Launch mass	5,963 kg (13,146 lb)
Dry mass	2,405 kg (5,302 lb)
Power	820 watts from a solar panel ~100 m² (1,100 sq ft)


Start of mission
Launch date	14 April 2023 12:14 UTC
Rocket	Ariane 5 ECA
Launch site	Centre Spatial Guyanais, ELA-3
Contractor	Arianespace


Flyby of Moon
Closest approach	August 2024
Flyby of Earth
Closest approach	August 2024
Flyby of Venus
Closest approach	31 August 2025
Flyby of Earth
Closest approach	29 September 2026
Flyby of Earth
Closest approach	18 January 2029
Flyby of 223 Rosa
Closest approach	15 October 2029 (proposed)
Jupiter orbiter
Orbital insertion	July 2031 (planned)
Orbital departure	December 2034 (planned)
Ganymede orbiter
Orbital insertion	December 2034 (planned)
Orbit parameters
Periapsis	500 km (310 mi)
Apoapsis	500 km (310 mi)

JUICE mission insignia Cosmic Vision ← Euclid SMILE →

The Jupiter Icy Moons Explorer (JUICE) is a special spacecraft launched by the European Space Agency (ESA). It took off on April 14, 2023. Its main goal is to study three of Jupiter's largest moons: Ganymede, Callisto, and Europa. Scientists believe these moons might have huge oceans of liquid water hidden under their icy surfaces. This makes them exciting places to look for signs of life!

JUICE will travel for about eight years to reach Jupiter. It will use a clever trick called a gravity assist to speed up its journey. In December 2034, JUICE will make history by becoming the first spacecraft ever to orbit a moon other than Earth's Moon. It will orbit Ganymede to get a super close look.

What is the JUICE Mission?

The JUICE mission is part of ESA's Cosmic Vision science program. It was chosen as a top mission on May 2, 2012. This mission builds on ideas from an earlier project called the Jupiter Ganymede Orbiter.

JUICE was picked over other cool ideas, like a powerful X-ray telescope and a way to study gravitational waves. In 2015, a company called Airbus Defence and Space was chosen to build the spacecraft in France.

JUICE's Amazing Journey

Launching into Space

JUICE was supposed to launch on April 13, 2023, but bad weather caused a delay. It finally launched on April 14, 2023, at 12:14 UTC. The spacecraft blasted off on an Ariane 5 rocket from the Guiana Space Centre. A few minutes later, its huge solar panels unfolded, which meant the launch was a success!

Traveling to Jupiter

To get to Jupiter, JUICE will perform several gravity assists. This means it will fly close to planets and moons to use their gravity to get a speed boost.

It will fly past the Earth–Moon system in August 2024.
It will visit Venus in August 2025.
It will have a second Earth flyby in September 2026.
A final third Earth flyby will happen in January 2029.

JUICE will also cross the asteroid belt twice. There's even a plan for it to fly past an asteroid called 223 Rosa in October 2029.

Arriving at Jupiter

JUICE is expected to arrive at Jupiter in July 2031. First, it will do a quick flyby of Ganymede. Then, about 7.5 hours later, it will enter orbit around Jupiter. Its first orbits will be long and stretched out, but they will slowly get closer to Jupiter over time.

In July 2032, JUICE will make its first close flyby of Europa. The spacecraft will also fly in a special orbit that lets it explore Jupiter's polar regions. This will help scientists study Jupiter's powerful magnetic field.

Orbiting Ganymede

In December 2034, JUICE will start orbiting Ganymede. This is a huge step, as it will be the first time a spacecraft orbits a moon other than Earth's! Its first orbit will be about 5,000 km (3,100 mi) away. By 2035, JUICE will be in a circular orbit just 500 km (310 mi) above Ganymede's surface. From there, it will study Ganymede's makeup and its own magnetic field.

Mission End

When JUICE runs out of fuel, it is planned to slowly fall out of orbit and crash into Ganymede. This will happen around the end of 2035.

Trajectories of JUICE

Around the Sun

Around Jupiter

Around Ganymede

Sun · Earth · JUICE · Venus · 223 Rosa · Jupiter · Ganymede · Callisto · Europa

Why Study Jupiter's Icy Moons?

Ganymede view by Galileo

Section of Europa's icy surface

The JUICE mission will look closely at Ganymede to see if it could support life. It will also study Europa and Callisto. All three moons are thought to have hidden oceans of liquid water under their ice. Understanding these icy worlds is key to learning about where life might exist beyond Earth.

Here are some of the main things JUICE hopes to find out about Ganymede and Callisto:

Find out about their ocean layers and if there are other water pockets underground.
Map their surfaces, including mountains, valleys, and what they are made of.
Study the properties of their icy crusts.
Learn about their insides, like how their mass is spread out and how they changed over time.
Investigate Ganymede's thin atmosphere.
Study Ganymede's own magnetic field and how it interacts with Jupiter's huge magnetic field.

For Europa, JUICE will focus on the chemicals needed for life, like organic molecules. It will also try to understand how Europa's surface features formed and what its non-ice parts are made of. JUICE will even use radar to look deep under Europa's ice for the first time. It will try to figure out how thick the ice crust is in active areas.

JUICE will also take pictures of some of Jupiter's smaller, irregular moons and the super-volcanic moon Io.

How the JUICE Spacecraft is Built

The JUICE spacecraft is designed to handle some big challenges.

It's very far from the Sun, so it needs huge solar panels to get enough power.
Jupiter has a very strong and harsh radiation environment that can damage electronics.
To get into orbit around Jupiter and Ganymede, and to do all its flybys, JUICE needs a lot of fuel. It carries about 3,000 kg (6,600 lb) of chemical propellant.

The spacecraft will use many gravity assists to help it on its journey:

To travel between planets (Earth, Venus, Earth, Mars, Earth).
To get into orbit around Jupiter and then lower its orbit using Ganymede's gravity.
To slow down using Ganymede and Callisto.
To change its orbit's tilt using 10-12 Callisto flybys.

Science Tools on JUICE

JUICE instruments

In 2013, ESA chose 11 science instruments for JUICE. These tools were built by teams of scientists and engineers from all over Europe, with help from the US and Japan. Japan also helped with testing and provided parts for several instruments.

Here are some of the main instruments:

JANUS: The Camera System

JANUS stands for "Jovis, Amorum ac Natorum Undique Scrutator," which is Latin for "comprehensive observation of Jupiter, his love affairs and descendants." This camera system will take detailed pictures of Ganymede and interesting parts of Callisto's surface. It can take very high-resolution images, showing details as small as 2.4 m (7 ft 10 in)! It has 13 different filters to capture light in various colors and can even take 3D pictures. JANUS will help scientists understand the geology of these moons.

MAJIS: Imaging Spectrometer

MAJIS (Moons and Jupiter Imaging Spectrometer) is like a super camera that can see different colors of light, even those we can't see. It will look at Jupiter's clouds and gases. On the icy moons, it will study what their ice and minerals are made of. It can see details as small as 75 m (246 ft) on Ganymede.

UVS: UV Imaging Spectrograph

UVS (UV Imaging Spectrograph) looks at ultraviolet light. It will study the very thin atmospheres (exospheres) and glowing lights (aurorae) of the icy moons. It will also search for plumes of water erupting from Europa. For Jupiter, it will study the upper atmosphere and aurorae.

SWI: Sub-millimeter Wave Instrument

SWI (Sub-millimeter Wave Instrument) uses a 30 cm (12 in) antenna to study Jupiter's atmosphere. It will also look at the thin atmospheres and surfaces of the icy moons.

GALA: Ganymede Laser Altimeter

GALA (GAnymede Laser Altimeter) is a laser altimeter. It shoots lasers at the moons to measure their height and shape. It can measure changes as small as 10 cm (3.9 in)! This will help scientists map the icy moons and see how Ganymede's shape changes due to Jupiter's gravity.

RIME: Radar for Icy Moons Exploration

RIME (Radar for Icy Moons Exploration) is like a powerful radar that can see through ice. It uses a 16 m (52 ft) antenna to send radio waves deep into the moons. It can see structures up to 9 km (5.6 mi) deep with a vertical detail of 30 m (98 ft) in ice. This will help find those hidden oceans!

J-MAG: JUICE-Magnetometer

The scalar sub-instrument (MAGSCA) is an optical magnetometer with low absolute error, that is part of J-MAG

J-MAG (JUICE-MAGnetometer) is a very sensitive tool that measures magnetic fields. It will help scientists find the subsurface oceans of the icy moons. It will also study how Jupiter's magnetic field interacts with Ganymede's own magnetic field.

PEP: Particle Environment Package

PEP (Particle Environment Package) is a set of six sensors. It will study the charged particles and gases around Jupiter and its moons. These particles are part of Jupiter's magnetosphere. PEP will measure different types of particles, from very low to very high energy.

RPWI: Radio and Plasma Wave Investigation

RPWI (Radio and Plasma Wave Investigation) will study the charged gas (plasma) and radio signals around the spacecraft. It has four different experiments and uses special probes and receivers. Fun fact: this instrument's logo includes the character Sonic!

3GM: Gravity and Geophysics

3GM (Gravity and Geophysics of Jupiter and Galilean Moons) is a radio science tool. It will help scientists study the gravity fields of Ganymede and the other icy moons. This will tell them how big the internal oceans are. It will also investigate the atmospheres of Jupiter and its moons.

PRIDE: Planetary Radio Interferometer and Doppler Experiment

PRIDE (Planetary Radio Interferometer and Doppler Experiment) will use signals from JUICE's antenna. These signals will be picked up by special telescopes on Earth. By precisely measuring these signals, scientists can learn even more about the gravity fields of Jupiter and its icy moons.