On Thursday morning, NASA’s Juno spacecraft descended to less than 358 km from the surface of Europa, the large ice-encrusted moon that orbits Jupiter.
This flyby will give humanity its closest look at Europa since the Galileo mission conducted several close flybys more than two decades ago. However, the Juno spacecraft will carry a suite of more powerful instruments and a much more capable camera than Galileo. So, this should be our best look at the intriguing world.
Launched in 2011, Juno reached Jupiter in 2016 to closely study the composition of the largest planet in the solar system, as well as its powerful magnetosphere. After successfully completing its primary mission in 2021, Juno mission operators began using the probe to assess moons in the Jovian system, including Europa, Ganymede, and Io.
Given Juno’s existing orbit and Jupiter’s massive gravity field, the orbital dynamics of Europa’s flyby are challenging, to say the least, and Juno had to make significant changes to its path.
“The relative speed between the spacecraft and the moon will be 23.6 kilometers per second, so we’re screaming pretty fast,” said John Bordi, Juno Mission Deputy Director at JPL. “All steps must go like clockwork to successfully acquire our planned data, because shortly after the flyby is complete, the spacecraft must be reoriented for our next close approach to Jupiter, which does not occur until seven o’clock. and a half later.”
Scientists have long been curious about Europa, which is covered in ice but is said to have a vast ocean below the surface due to the moon’s hot core. There is probably more liquid water in Europe’s global ocean than there is on Earth, planetary scientists believe. While the ice sheet is believed to be several kilometers thick, the Hubble Space Telescope has collected data indicating that geysers can periodically eject through cracks in this ice. Given the presence of water and heat, this ocean is considered a potential reservoir for microbial extraterrestrial life.
Juno will bring new tools to study this ice sheet. For example, the spacecraft’s microwave radiometer will examine Europa’s crust, obtaining data on its icy composition and temperature. This is the first time that such data will be collected to study the moon’s icy shell.
The visual imagery and science data will help inform NASA scientists as they complete assembly of the Europa Clipper, a large spacecraft set to launch in 2024 on a Falcon Heavy rocket. This mission will be dedicated to studying the moon, arriving in 2030 and performing more than 50 short-range flybys to collect data. Eventually, the space agency would like to send a lander but first wants to get data from flyby missions to assess the best location for landing, potentially near a water vapor plume, if they really exist.
Images should start returning from the Juno flyby of Europe in the coming days. NASA will post them here as they arrive.
