This is the most accurate measurement of the size of the planet over the past 40 years.
Jupiter has no solid surface. Therefore, scientists focus on the pressure level of 1 bar – an analogue of earthly atmospheric pressure at sea level. It is this “baric surface” that is considered the conditional border of the planet. Previously, it was measured by the Voyager and Pioneer devices using radio waves, but their data turned out to be less accurate.
According to the measurements of “Juno”, the diameter of Jupiter at a pressure of 1 bar is less than 8 km than previously considered. In addition, the planet turned out to be more flattened at the poles due to a super-fast rotation: Jupiter performs one revolution in just 9 hours 56 minutes.
Size adjustment helps to simulate atmospheric processes and a magnetic field, clarifies Jupiter's interaction with its satellites, such as IO and Europe, and also affects calculations for future cosmic missions.
Context
“Juno”, which has been in Jupiter since 2016, continues to open new details about the atmosphere, polar radiance and the internal structure of the planet. Initially, they wanted to complete the mission in 2021, but it was extended at least until 2025.
