A SpaceX Falcon Heavy rocket with the Europa Clipper spacecraft aboard launches from Launch Complex 39A at NASA's Kennedy Space Center in Cape Canaveral on Oct. 14, 2024.GREGG NEWTON/AFP/Getty Images
The most ambitious mission to the outer solar system in a generation is under way.
NASA’s Europa Clipper launched atop a Space X Falcon Heavy rocket at 12:06 p.m. ET on Monday, marking the start of a 5½-year journey to Jupiter.
The 5.8-tonne uncrewed spacecraft is the largest ever sent to another planet, mainly because of its giant solar panels that span 30.5 metres, which will supply it with power in a region of the solar system where the sun appears only one-25th as bright as it does on Earth.
A crucial milestone for Europa Clipper came just hours after launch, when it successfully unfolded its solar panels for the long trip ahead.
Ultimately, the mission’s goal is to conduct an in-depth examination of Europa – a moon of Jupiter whose icy crust conceals a subterranean ocean and could support an alien ecosystem.
“There’s very strong evidence that the ingredients for life exist on Europa but we have to go there to find out,” said Bonnie Buratti, the mission’s deputy project scientist, during a news briefing last month to preview the mission.
Europa Clipper, which is expected to cost US$5.2-billion by the time its mission is completed in 2034, is not built to land on Europa or look for signs of life directly. Instead, it will orbit Jupiter while conducting dozens of close passes of Europa to examine the chemical composition of its surface and make use of ice-penetrating radar and magnetic measurements to sense the ocean below.
Jupiter's moon Europa was captured by the JunoCam instrument aboard NASA's Juno spacecraft during the mission's close flyby on Sept. 29, 2022.Supplied
Of special interest is the nature of the brown streaks and cracks that were first spotted by Voyager 2 in 1979, which give Europa the appearance of an outdoor skating rink that partly broke up and then refroze.
Scientists have long suspected that chemical compounds such as salts and sulphates are present in Europa’s hidden ocean and may have spilled onto its surface at times when the moon’s crust has flexed and cracked open. It’s also possible that there are fresh plumes of water vapour escaping to the surface today. An examination of those compounds on the surface should help reconstruct the contents of the ocean, including whether it contains any traces of organic molecules that could act as building blocks for life.
Europa is one of a handful of icy moons orbiting the solar system’s giant planets where researchers say a combination of energy, chemical nutrients and water in liquid form could make life possible. But until recently, the only missions sent to explore the potential for life elsewhere in our solar system have been aimed at Mars.
“I think actually this marks an interesting turning point because even though we talk about these icy moons a lot, this will mark the first time that a mission is moon-focused,” said John Moores, a planetary scientist at York University in Toronto and author of Daydreaming in the Solar System.
Last year the European Space Agency launched the Jupiter Icy Moons Explorer (JUICE), a €1.6-billion probe that is designed to survey the Jupiter system and will also make measurements of Europa along with the planet itself and two other large moons, Ganymede and Callisto.
The European probe’s somewhat different trajectory will bring it to Jupiter by 2031, one year later than Europa Clipper’s scheduled arrival.
“Ultimately, having Europa Clipper and JUICE simultaneously operating in the Jupiter system and with different focuses will ensure full complementarity in achieving the scientific objectives regarding the three icy Galilean moons and the planet,” said Federico Tosi, a senior research scientist with Italy’s National Institute for Astrophysics and a member of the JUICE science team.
With a diameter of 3,100 kilometres, Europa is similar in size to Earth’s moon but is otherwise utterly different. It was discovered by Galileo when he first turned his telescope toward Jupiter in 1610 and saw four large satellites racing around the giant planet.
Moving outward from Jupiter, Europa is the second of the four – a placement that has shaped its destiny over the eons. Caught between the gravitational pull of Jupiter and its neighbouring moons, Europa is repeatedly squeezed by tidal forces that warm its rocky interior and prevent its ocean from freezing.
The implication is that Europa may have a suitable environment for the emergence of microbial life, particularly if there are deep sea vents on its ocean floor where chemical processes can sustain life in the absence of sunlight, just as occurs in Earth’s oceans.
If Europa Clipper’s results are intriguing enough, it could prompt a follow-up mission to land on its icy surface or even send a submersible probe to directly explore the ocean under the ice.
Before then, said Dr. Buratti, there is plenty to look forward to from Europa Clipper.
“Every mission we’ve ever been on – we’ve always uncovered things we could not have imagined,” she said. “That is the thing that most interests me.”
A NASA spacecraft rocketed away Monday on a quest to explore Jupiter’s tantalizing moon Europa and reveal whether its vast hidden ocean might hold the keys to life.
The Associated Press