The Jupiter-orbiting spacecraft Juno got a three-year lease on life this past week from NASA to study the solar system’s biggest planet until at least 2021
Juno, which left Earth in 2011 and arrived in Jupiter’s orbit in July 2016, will use the extra time to see what the likely oldest planet in the solar system can tell us about how all planets are formed, and to help us better understand the northern lights (aurora borealis) as compared to the auroras in a vastly different upper atmosphere. (I know what you’re thinking: Aurora Borealis. At this time of year? At this time of day? In this part of the solar system? Localized entirely within the northern pole of Jupiter?)
“We have an incredible tool now orbiting Jupiter that’s going to tell us about how it’s made inside, how it was formed,” Scott Bolton, space physicist and principal investigator for the Juno mission, tells Inverse. “It’ll tell us about the early solar system; it tells us how planets are made in general. It will teach us steps of planetary making not just in our own solar system but potentially how it works elsewhere.”
“So, we’re searching for answers that have to do with, ‘How did we get here?’ Jupiter holds those secrets for us.”
The main reason for Juno’s so-called extension is merely a technical issue. Trouble within the probe’s thruster valve and concerns over its fuel system forced the research team to adjust its orbit around the gas giant to a 53-day-long ellipse extending far away from Jupiter itself, only swinging close by for one of those days. (Juno’s original orbit was much shorter, 14 days long.) It was an early problem that has limited how much research Juno can do on the planet, and frankly, a total bummer.
But, the additional 41 months in orbit will give Juno a chance to actually achieve its original science objectives — which is good news, given how expansive they are.
Jupiter was very likely the first planet formed in our solar system, pulling in the vast amount of gas and dust swirling around about 4.6 billion years ago. Rival theories about how planets form in the first place will live or die based on data collected by Juno. Did Jupiter’s core form first, pulling in all the easy to grab hydrogen and helium gas second? Or was it formed by a eddy-like collapse inside that original nebula of dust and gas? Juno may find the answer.
Speaking over the phone from the Asia Oceania Geosciences Society (AOGS) 15th Annual Meeting in Honolulu, Hawaii (“Great seafood.”), Bolton says that the need for Juno’s nearly two-month-long orbits is something of a blessing in disguise. These long arcs will allow Juno to study the planet’s massive magnetosphere and its effects on upper atmospheric phenomena like Jupiter’s own aurora, its equivalent to Earth northern and southern lights.
“We thought Jupiter’s aurora would look and work sort of similar to the way Earth’s does but it’s actually quite different,” Bolton says. “And we’re still struggling to figure it all out, but it’s really fascinating.”