On Thursday morning, NASA’s Juno spacecraft swooped 358 kilometers from the surface of Europa, the large, ice-covered moon orbiting Jupiter.
This flyby will provide humanity with a closer look at Europe since the Galileo mission made several close flights more than two decades ago. However, the Juno spacecraft will carry a much more powerful instrument cluster and a much more capable camera than Galileo. So this has to be the best look yet at the interesting world.
Launched in 2011, Juno arrived at Jupiter in 2016 to closely study the composition of the solar system’s largest planet, as well as its strong magnetosphere. Having successfully completed its primary mission in 2021, Juno mission operators began using the probe to evaluate satellites in the Jovian system, including Europa, Ganymede and Io.
Given Juno’s current orbit and Jupiter’s massive gravitational field, the orbital dynamics of Europa’s flyby are challenging, to say the least, and Juno has had to make major adjustments to its trajectory.
“The relative velocity between the spacecraft and the moon would be 23.6 kilometers per second, so we’re screaming really fast,” John Purdy said, Deputy Mission Director of Juno at Jet Propulsion Laboratory. “All steps have to go like clockwork to successfully get our planned data, because soon after the flyby is complete, the spacecraft needs to be redirected to our next close approach to Jupiter, which happens just seven and a half hours later.”
Scientists have long been curious about Europa, which is covered in ice but believed to have a vast ocean beneath the surface due to the moon’s warm core. Planetary scientists believe that there is likely more liquid water in the global ocean Europa than there is on Earth. While the ice sheet is believed to be several kilometers thick, the Hubble Space Telescope has collected data indicating that geysers may periodically vent through cracks in this ice. Due to the presence of water and heat, this ocean is a potential reservoir for exotic microbial life.
Juno will bring new tools to study this ice cap. For example, the spacecraft’s microwave radiometer will look at Europa’s crust, obtaining data on its ice composition and temperature. This is the first time such data has been collected to study the lunar cryosphere.
Visual images and scientific data will help inform NASA scientists who complete assembly of the Europa Clipper spacecraft, a large spacecraft scheduled for launch in 2024. On a Falcon Heavy missile. This mission will be devoted to studying the moon, which will arrive in 2030 and make more than 50 close-range flights to collect data. Ultimately, the space agency would like to send a lander but wants to get data from the flyby missions first to assess the best landing site, possibly near a plume of water vapor, if it already exists.
Pictures should start coming back from Juno’s voyage in Europa in the next several days. NASA will Post them here when they arrive.