Juno itself is an amazing feat. It’s the first solar powered spacecraft to reach the outer planets. It’s one of the fastest spacecrafts ever made. And it has pulled-off an incredible and dangerous maneuver, entering orbit around the gas giant.
But the really amazing things will be the science it does as it orbits the planet.
One of the big questions is: what’s at the core of Jupiter? Scientists aren’t sure whether it started off as a rocky planetary core, which then gathered all the gas that today makes up most of the planet, or whether it formed from an unstable region in a gas cloud.
Another question scientists hope to answer is how much water is in the planet. For scientists, that’s a measure of how much oxygen there is – locked up as the O in H2O. Based on measurements made from Earth, there seems to be less oxygen on the planet than there is in other objects in that region of the solar system.
If there turns out to be lots of water – and so lots of oxygen – that would suggest the planet formed near the sun. If there is relatively little water, that would suggest it formed further out in the solar system, and migrated in.
How does that eye remain so stable? By diving below the clouds, Juno aims to map the structure and the motion of the atmosphere. That will help scientists see how deep the features we see on the surface penetrate, and figure out how they formed and why they remain for so long.