Five years and 540 million miles after launch, the solar-powered spacecraft Juno has reached Jupiter.
It took 48 minutes for Juno’s radio signal to reach Earth. But despite concerns over electronic-frying radiation and potentially damaging debris in the planet’s ring, it safely reduced speed and slid into orbit late Monday.
“Juno, the wife of Jupiter, was always looking for what paramours and other secrets,” said Wayne Wooten, an astronomer at Pensacola State College. “That’s what Juno is going to be probing for – Jupiter’s deeply-hidden secrets.”
The 20-month mission will study the planet’s magnetic field, gravitation and it’s interior. To do that, Juno will be maintaining a polar orbit for the next 53 days, along with ducking in and out of Jupiter’s radiation belt while gathering data.
“It’s going to be turning and sending information it gained from its close passes right above Jupiter’s cloud tops,” Wooten said. “We’re hoping we’ll have as many as 30 of these trips above and below Jupiter, before finally the radiation fields destroy the sensors.”
The orbit will be shortened to 14 days in October, setting up repeated low-altitude passes within a few thousand miles of Jupiter's turbulent atmosphere. The probe is also breaking new ground, as the first solar-powered spacecraft to venture as far away from Earth as Jupiter.
Another assignment for the probe is to determine what type of core, if any, exists at the center of Jupiter. Wooten says if there is a core, it may not be much different than the center of Earth.
“Other than being extremely hot, above that you’re going to have probably a lot of liquid metallic hydrogen,” said Wooten. “Hydrogen isn’t a metal, but it does act like a metal when you press it hard enough. And that’s what we think makes up Jupiter’s magnetic field.”
Calling it “Old Home Week,” Wooten says the Juno mission gives him a chance to look back at an early part of his career in the 1960s at the University of Florida.
“I helped build the radio observatory and I manned it for many years as an undergraduate and later as a graduate student,” said Wooten.
And at the end of Juno’s 20-month mission, plans are to crash it into the surface of Jupiter for a reason – to avoid it crashing into Europa or one of Jupiter’s other moons and contaminating them with terrestrial bacteria, in case there is life or the building blocks for life on them.
Juno, says NASA, will provide a giant step forward in understanding how giant planets form, and their role in the formation of the rest of the solar system. More on the Juno mission can be found at NASA's website.