Status: 04/13/2023 05:31 a.m
Is there a chance for further life in our solar system? A new ESA mission aims to answer this question, hundreds of millions of kilometers away. After years of preparation, the Jupiter probe “Juice” is scheduled to launch today.
When the “Juice” space probe is lifted off today with an “Ariane 5” rocket, it has a long journey ahead of it. It will only arrive at Jupiter in July 2031 to explore the largest planet in our solar system and three of its moons.
Along with Saturn, Uranus and Neptune, Jupiter is one of four gas planets. They lie in the so-called outer solar system, while Mercury, Venus, Earth and Mars belong to the inner solar system and are rocky planets.
With the “Juice” mission, the scientists hope to gain fundamental insights into the structure and functioning of gas planets and our solar system as a whole.
Angela Dietz, who works as a space engineer at the European Space Agency ESA and is responsible for “Juice”, explains:
Jupiter is not entirely dissimilar to the Sun. It has a similar structure, consisting of helium and hydrogen. It is itself like a small solar system with more than 90 moons around it. If we know more about Jupiter and its moons, we can find out a bit how a small solar system works.
How does Jupiter interact with its moons that orbit it? How does its atmosphere react to asteroid and comet impacts? Scientists are hoping for answers to such questions. The researchers are also interested in the so-called Great Red Spot – a huge hurricane on the surface of the planet. Why is he shrinking? What chemical processes take place inside?
Instruments also from German development
The “Juice” probe is not the first science mission to Jupiter and its moons. NASA’s Juno probe is currently orbiting Jupiter. In the 1970s, the “Voyager” probes had already made their journey to the gas planet.
The research will now continue with new, ultra-modern instruments. Walther Pelzer, Head of the German Space Agency at the German Aerospace Center, DLR, explains:
ESA’s largest planetary mission to date is on its way to the largest planet in our solar system. ‘Juice’ will observe and survey Jupiter and its three large icy moons Ganymede, Callisto and Europa in fly-by and from orbit using cameras, spectrometers, radar and lasers. Two important instruments were developed and built under German direction. Institutions from Germany are decisively involved in another five.
Are there really huge oceans of water beneath the ice crusts of the moons? The researchers want to find out. Her main focus is on Jupiter’s moon Ganymede. It is the largest moon in the solar system. Engineer Dietz explains: “There are various instruments on board ‘Juice’ that we use to examine the Ganymede, such as a laser altimeter. We shoot a laser, so to speak, and scan the surface.”
In this way, the scientists examine the topography of the moon, as well as the elevation and depression of its surface. Dietz continues: “Then we have a radar that looks under the ice surface and a magnetometer. With it we can, for example, explore the thickness of the iron core inside the moon.” Ganymede is one of the few bodies in our solar system that has a magnetic field – alongside Earth and Mercury. “This magnetic field is created by the liquid iron core, like Earth’s.”
The final preparations are underway: The “Juice” probe is being unpacked at the European spaceport in French Guiana.
Image: dpa
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All in all, Ganymede can be examined so thoroughly with the various instruments that an overall picture of its structure is created at the end and the scientists can then draw conclusions about the amounts of water present, Dietz describes. The mission could not prove life directly because no lander touched down on the surface. “But we can investigate whether the conditions on the moons are conducive to life, such as water, energy and stability,” says Dietz.
In addition, a NASA probe is scheduled to fly to Jupiter’s moon Europa next year and explore it in detail. The missions complement each other and also serve to prepare for a future lander mission. Thomas Zurbuchen, NASA’s former chief of science, says:
I really feel like the way we think about life is going to totally change in ten or twenty years. You never know exactly – like when hiking a mountain in a place you’ve never hiked before – how long the way to the top is. But there are so many ways to make progress that twenty years is actually a good time frame.
Flybys of the Earth, Moon and Venus
On its way to Jupiter, the “Juice” probe flies past the Earth, the Moon and Venus several times in order to save fuel through the corresponding gravitational boost. “Juice” travels to Jupiter in a roundabout way, so to speak. Angela Dietz explains:
We save up to a ton of fuel by doing flybys with ‘Juice’. During its flybys of the Earth, Moon and Venus, the probe uses gravity to gain momentum. ‘Juice’ weighs a total of six tons, and already more than half is fuel. Without the flybys, the probe would have to carry five more tons of fuel.
Such gravity deflections on planets are standard on interplanetary probes. The special thing about the journey of “Juice” is that for the first time a combined gravity diversion is carried out on the Earth’s moon and 36 hours later on Earth.
challenges on the journey
The flight route presented the scientists with particular challenges, because the sensitive instruments of “Juice” have to be well protected. The probe has to withstand very large temperature fluctuations: from 250 degrees near Venus to more than minus 200 degrees on Jupiter. Added to this is the high level of radiation and the lack of sunlight. Sunlight is 25 times weaker on Jupiter than on Earth. Huge solar panels with an area of 85 square meters will capture the light to power the spacecraft.
change of orbit
When “Juice” reaches Jupiter, there will be another premiere. After numerous orbits around Jupiter and flybys of its moons, the probe is scheduled to leave Jupiter’s orbit in 2034 and enter an orbit around Ganymede. This would make “Juice” the first probe to change from the orbit of another planet to one of its moons.
The mission is monitored and controlled from the ESA control center ESOC (European Space Operations Centre) in Darmstadt. An exciting decade of work with many unknowns lies ahead of the ESA experts. “Juice” flight operations manager Andrea Accomazzo says: “This is the largest mission into deep space that we have ever launched.”