Next week, Europe will fly its first mission to the Jupiter system to discover the gas giant and three of its intriguing moons.
The European Space Agency (ESA)-led Jupiter Icy Moons Explorer spacecraft, or JUICE, will launch on Thursday (April 13) from Europe’s Spaceport in French Guiana. JUICE, full of what ESA describes as (opens in new tab) “the most powerful payload ever flown to the outer solar system,” was lately cocooned contained in the Ariane 5 rocket that can fly it to space.
This “means that we have seen the spacecraft for the last time ever,” ESA introduced on the mission’s Twitter (opens in new tab) account on Wednesday (April 5). “And that we are one step closer to launch!”
Shortly after taking off, JUICE will separate from the rocket, fan out its solar panels and kick begin its 7.6-year-long cruise to the largest planet within the solar system.
During its time within the Jovian system, JUICE’s principal objective will probably be to check Jupiter and three of its largest moons: Europa, Callisto and Ganymede. The spacecraft doesn’t have a lander, so it won’t contact down on any of its targets, however it’s going to fly by all moons a number of occasions to gather beneficial knowledge.
Between 2021 and 2034, JUICE will whisk by Europa solely twice, skimming as little as 248 miles (400 kilometers) above the moon’s floor. The spacecraft may also whirl previous Jupiter’s second-largest moon Callisto 21 occasions and conduct 12 flybys of Ganymede, in keeping with the mission launch kit (opens in new tab).
In 2034, the spacecraft will enter orbit immediately round Ganymede, making it the primary moon apart from Earth’s to have a spacecraft in its orbit. The mission will self-destruct a 12 months later by crashing into Ganymede’s floor.
“[The moons] are special in the sense that we think they contain in their interiors vast oceans of liquid water, which is kind of fascinating,” Olivier Witasse, undertaking scientist of the JUICE mission, instructed Space.com.
Mainly, JUICE will gather knowledge to substantiate the presence of such liquid water — essential for all times as we all know it — beneath the surfaces of those moons, which was solely hinted at by the Galileo mission again within the 1900s.
“I am really looking forward to seeing the findings after we arrive at [the] destination in 2031,” Witasse mentioned. “I am just curious and patient (I have to [be]!)”
Ganymede: A uniquely sophisticated world
Ganymede, the most important moon within the solar system, will probably be JUICE’s essential scientific goal, and for good purpose.
Ganymede has a radius of 1,635 miles (2,631.2 km), which is only a bit smaller than that of Mars, and is 4.5 billion years previous, inserting it on the identical age as its guardian planet. Scientists suppose the moon fashioned from gasoline and dust left over from Jupiter’s formation, and the truth that it has been round since early within the solar system’s historical past makes it of immense scientific worth.
Back in 1996, when the Galileo spacecraft ventured simply 164 miles (264 km) above Ganymede’s floor, scientists have been perplexed to discover (opens in new tab) its distinct planet-like magnetic area. To date, Ganymede is the one moon within the solar system identified to boast a magnetic area of its personal.
As Ganymede orbits Jupiter — which has its personal huge magnetic area — from 665,000 miles (1 million km) away, the moon’s magnetic area is partly immersed in that of the gas giant. This interplay is sophisticated and distinctive and triggers bewildering phenomena on the moon, just like the dancing auroras that “rock back and forth” in response to modifications in Jupiter’s magnetic area.
Ganymede can be distinctive in internet hosting a floor that betrays its historical past for billions of years. In addition to having the largest impact crater amongst all solar system our bodies, the moon is scarred with many craters, which dent 40% of its floor. The remaining 60% is stuffed with numerous grooves that crisscross for hundreds of miles.
Moreover, its subsurface ocean seemingly harbors extra water than these of Earth, and scientists lately discovered that youthful elements of the moon might have been formed by some flooding on its floor.
Together, this number of floor options with equally numerous ages makes the moon a scientific searching floor to be taught in regards to the historical past of the floor in addition to its previous and present geological exercise.
Ganymede’s subsurface ocean is considered sandwiched between layers of ice, making the moon unlikely to host alien life, researchers say (as a result of there’s seemingly not a lot fascinating chemistry happening in that water). So the JUICE crew is assured that ramming the spacecraft into Ganymede’s floor on the mission’s finish will not contaminate a life-hosting world. And this motion will defend a unique moon considered extra pleasant to life — Europa.
Europa: ‘A cracked egg’
Europa would be the smallest of the 4 principal moons of Jupiter, found by famed seventeenth century astronomer Galileo Galilei, however it’s considered among the best locations for alien life to sprout.
Europa, not like Ganymede, is comparatively lively, due to being nearer to Jupiter. Due to that closeness, the gas giant has vital gravitational affect on Europa, as seen within the moon’s giant tides that stretch and compress its frozen floor. At occasions, such exercise cracks its youthful floor, which scientists suppose is barely 20 million to 180 million years previous, forming fractures and ridges that stretch for hundreds of miles and overlap to kind their very own intricate design.
Such options are seen as strains that “scratch” the moon’s floor, which scientists suppose might also host salt brought up from the underground ocean considered 40 to 100 miles (60 to 150 km) deep. This newly surfaced salt is bombarded by radiation, giving it a signature reddish-brown coloration, however the course of that results in this mysterious materials is just not effectively understood.
Perhaps probably the most fascinating side of Europa is the occasional glimpse it gives of a world ocean hidden beneath its 15-mile-thick (20 km) icy floor. In the previous few years, scientists think they have spotted proof of sporadic water plumes blasting from the moon’s frigid floor. Such plumes, which can rise 120 miles (200 km) excessive, are thought to originate from the moon’s hidden ocean. However, scientists know little in regards to the processes that drive these mechanisms on the oceanic world.
Europa’s frozen floor additionally has puddles of melted water, which scientists suppose could possibly be “cozy habitats” for alien life. And its ocean is considered in touch with its rocky core, permitting a wide range of advanced chemistry to happen.
The geologically lifeless Callisto
Jupiter’s second-largest moon Callisto, which is sort of as huge as Mercury and has 142 identified craters marking its floor, is among the many most battered moons within the solar system.
Unlike Europa’s floor, which is younger due to the moon usually recycling its floor, Callisto was as soon as considered an “ugly duckling moon,” due to the dormancy on its 4.5 billion-year previous floor.
Countless asteroid impacts have punctured Callisto’s floor, and the ensuing craters haven’t modified a lot since they started accumulating 4.5 billion years in the past. For instance, Earth heals itself by recycling its surface repeatedly by way of plate tectonics. Callisto, however, is unable to do the identical, so the moon was lengthy considered a boring place to discover, not to mention seek for alien life.
Although there aren’t any water plumes blasting from Callisto’s floor, scientists suppose the moon does host a salty ocean beneath its punctured floor. They discovered this due to knowledge collected by the Galileo spacecraft, which put the moon again on the map of fascinating worlds within the Jupiter system to discover.
A second thriller involving Callisto is its mysterious skill to repeatedly replenish its ambiance, which is dominated by carbon dioxide however is outwardly so skinny that particular person gasoline molecules are “literally drifting around without bumping into one another,” NASA’s Robert Carlson, who was the principal investigator of the Galileo spacecraft’s devices, said at the time. Because the ambiance is so weak, it simply disperses into space, however scientists don’t but understand how the moon appears to again and again substitute it.
Unsolved puzzles about Jupiter
You may suppose we all know all that we have to about Jupiter, the most important planet within the solar system. But scientists truly know very little in regards to the evolution of the gas giant, whose thick ambiance and absence of a strong floor results in fascinating however puzzling phenomena.
For instance, Jupiter options sturdy auroras at its north and south poles. Scientists have been learning these Jovian lights for not less than 4 many years, however they nonetheless do not totally perceive how they’re created. The gas giant’s skill to host a number of life-friendly moons in its system can be one of many unsolved mysteries, one which the JUICE mission will attempt to unlock.
To perform its explorations of the Jupiter system, JUICE carries with it a set of 10 advanced and delicate devices. From a technical perspective, “building JUICE was not easy,” Witasse instructed Space.com. Preparing the spacecraft, which wants numerous gas to navigate, to be sturdy sufficient to face Jupiter’s sturdy and harmful radiation is not any small feat. Part of the mission’s growth occurred through the pandemic, including to the problems for the JUICE crew.
“But all in all, we managed, and we are ready to launch,” Witasse mentioned.