The probe with the two cross-shaped solar panels will be on the road for almost eight years, passing the moon, Venus and several times the earth.

Only then, in July 2031, will it have reached its destination, Jupiter.

However, ESA's JUICE mission is not really interested in the largest planet in the solar system.

It is its moons, and in particular the largest Galilean Ganymede, Kallisto, Europa and Io, that JUICE is supposed to find out new things about.

Specifically, it is about one of the biggest questions in astrophysics: Could alien life have arisen elsewhere in the solar system?

Sibylle Anderl

Editor in the feuilleton, responsible for the "Nature and Science" department.

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That such life is believed to be possible in the cold outer reaches of the solar system may come as a surprise.

Because of course it's alien planets first of all, and especially the earth-like ones, that come to mind when you're looking for aliens.

Thousands of alien planets in alien solar systems have been discovered over the past thirty years, and it seems far from improbable that the right conditions for life to exist somewhere could exist there.

Liquid water is the most important basic ingredient for life.

The first step in assessing a planet's potential livability is therefore to look at the distance between it and its host star.

The prerequisite is that this lies in an annular region where the planetary surface temperatures - influenced by the planet's atmosphere - are low enough not to allow water to completely evaporate and at the same time high enough not to turn the planet into an ice planet to let.

However, the right amount of stellar radiation, which can both energize potential life and enable the existence of liquid water, is not everything: In order to enable conditions that are stable over time, the star should not change too quickly.

The most massive and brightest stars use up their fuel within millions of years.

This is probably not enough time for the evolutionary development of halfway interesting life forms.

Dwarf stars like our Sun, on the other hand, offer constant conditions for many billions of years.

If all that is given - water, the right amount of energy and enough time - then it probably still needs carbon chemistry, since this allows for a complexity necessary for life.

But it can be found practically everywhere in the medium between the stars.

ESA with its JUICE mission

In the young solar system, all these basic ingredients were not only on Earth, but also on Mars, on whose surface traces of rivers, lakes and oceans can still be found today - which, by the way, is why NASA's Perseverance rover is looking for traces of life in a former river delta.

In the early 2030s, the samples collected by the rover are to be brought back to Earth.

The investigation methods available here in the laboratory will then finally make it possible to definitively clarify whether microbes were once able to develop on Mars.