Launch for the icy moons of Jupiter project, from the European Space Agency

The European spacecraft that was headed towards Jupiter’s icy moons has left the planet.

An Ariane-5 rocket launched from the Kourou spaceport in French Guiana carrying the Juice satellite into orbit.

After Thursday’s launch attempt had to be aborted due to weather, the European Space Agency programme is experiencing second chances.

To explore Callisto, Ganymede, and Europa—the three largest moons in the Solar System—the Jupiter Icy Moons Explorer (Juice) is being dispatched to the largest planet in the Solar System.

It is believed that these ice-covered planets contain enormous liquid water reserves.

The possibility that the moons could support life intrigues scientists.

This may come off as improbable. Only one-quarter of the light that hits Earth is received by Jupiter, which is located in the chilly, outer reaches of the Solar System and far from the Sun.

However, because of the gravitational pressure that the gas giant planet places on its moons, it’s possible that they could contain enough heat and energy to support rudimentary ecosystems, such to those that exist near volcanic vents on the ocean floors of Earth.

According to mission scientist Prof. Emma Bunce of Leicester University, UK, “In the case of Europa, it’s thought there’s a deep ocean, perhaps 100km deep, underneath its ice crust.”

“That depth of the ocean is ten times greater than the depth of the deepest ocean on Earth, and we believe that the ocean is in contact with a stony floor. The scenario that results from that offers mixing and some intriguing chemistry, the researcher told BBC News.

Ariane has the power to deliver Juice directly to its destination, at least not in a timely manner.

Instead, a course around the inner Solar System will be taken by the spacecraft after being launched by the rocket. The expedition will then be gravitationally thrown out to its final location after several fly-bys of Venus and Earth.

It takes 8.5 years to go 6.6 billion kilometres. The estimated date of entry into the Jovian system is July 2031.

Galileo Galilei, an Italian astronomer, used a newly developed telescope to find the ice-covered moons Callisto, Ganymede, and Europa in 1610. They seemed to him as tiny specks orbiting Jupiter. He could also make out Io, a much smaller world with volcanoes, which is the fourth body that we currently know about.

The 4,800–5,300 km diameter of the three ice objects varies. The size of the natural satellite orbiting the Earth is approximately 3,500 km.

Juice will remotely study the moons. In other words, it won’t land there; it will simply fly over their surfaces. The satellite’s final destination is the biggest moon in the Solar System, Ganymede. In 2034, it will enter orbit around this planet to complete its journey.

Radar will be used to look into the moons; lidar, a laser measurement tool; magnetometers will examine their complex electrical and magnetic surroundings; and other sensors will gather information on the swirling particles that surround the moons. Naturally, cameras will transmit back a tonne of images.

Juice won’t be searching for certain “biomarkers” or diving to the bottom of the water in search of alien fish.

In order for succeeding missions to more effectively address the life question, it must acquire additional data regarding potential habitability.

Scientists are already planning ways to deploy landers on one of Jupiter’s icy moons so that they can bore through the surface to reach the ocean below.

For the purpose of deploying submersibles where the local ocean is frozen over, researchers in Antarctica use heat to dig hundreds of metres through the ice sheet.

It’s difficult labour, and on a jovian moon where the ice cover can be tens of kilometres thick, it would be an even more difficult effort.

Juice won’t be operating in isolation.

Nasa, the US space agency, is launching Clipper, a personal satellite.

Although it will depart Earth after Juice the next year, it ought to come right on the heels of its European brother. It has the advantage of a stronger launch rocket.

While concentrating on Europa, Clipper will carry out much of the same work.

Prof. Carole Mundell, the director of science at the European Space Agency, said, “There is great complementarity and the teams are very keen to collaborate.”

“Undoubtedly, there will be a lot of data. However, we must first ensure that our missions reach Jupiter and are carried out safely.