On Thursday morning, NASA’s Juno spacecraft came within 358 km of Europa, the large, ice-covered moon orbiting Jupiter.
The flight will provide humanity with its closest view of Europa since the Galileo mission made several close flybys more than two decades ago. However, the Juno spacecraft will carry a more powerful suite of instruments and a more capable camera than Galileo. So this should be our best glimpse into the fascinating world.
Launched in 2011, Juno reached Jupiter in 2016 to take a closer look at the composition of the Solar System’s largest planet, as well as its powerful magnetosphere. After successfully completing its primary mission in 2021, Juno’s mission operators began using the probe to assess moons in the Jovian system, including Europa, Ganymede and Io.
Given Juno’s current orbit and Jupiter’s massive gravitational field, the orbital dynamics of a Europa flyby are challenging to say the least, and Juno has had to make significant changes to its trajectory.
“The relative velocity between the spacecraft and the Moon will be 23.6 kilometers per second, so we’re screeching along pretty fast.” John Bordy said, Juno is the deputy mission manager at JPL. “In order to successfully obtain the data we planned, all steps must go like clockwork, because shortly after the end of the flight, the spacecraft must be reoriented to approach Jupiter, which will happen only seven and a half hours later.”
Scientists have long wondered about Europa, which is covered in ice but is believed to have a large ocean beneath the surface due to the moon’s hot core. According to planetary scientists, there is more liquid water in Europa’s global ocean than on Earth. Although the ice sheet is believed to be several kilometers thick, the Hubble Space Telescope has collected data showing that geysers periodically erupt from cracks in this ice. Given the presence of water and heat, this ocean is considered a potential reservoir for microbial alien life.
Juno will bring new instruments to study this ice sheet. For example, the spacecraft’s microwave radiometer will probe Europa’s crust to learn about its ice composition and temperature. Such data will be collected for the first time to study the icy crust of the moon.
The visuals and scientific data will help inform NASA scientists as they complete assembly of Europa Clipper, a large spacecraft slated for launch in 2024. on the Falcon Heavy rocket. This mission will arrive in 2030 and will be devoted to the study of the Moon, making more than 50 close flybys to collect data. Eventually, the space agency would like to send a lander, but would also like to get data from flyby missions to assess the best place to land, potentially near water vapor, if indeed there is one.
Images should start coming back from Juno’s Europa flyby in the next few days. NASA will post them here as it comes.
