One mission that we don’t have to wait for is NASA’s Juno. That amazing spacecraft has been doing close flybys of Jupiter since 2016, analyzing the magnetic fields, the atmosphere, and even the moons. Now, in a new paper published in Astronomy & Astrophysics, scientists have determined that Jupiter’s atmosphere isn’t a homogenous mix of gases and actually contains a significant amount of metals. And by metals, we mean elements that aren’t hydrogen or helium.

Okay, we have a confession to make. The press release for this story came out early in June but didn’t cross our radar until yesterday when a trending article on Twitter had the title Bizarre news story of the day: Jupiter apparently ‘eats’ other planets. That got our attention, and so we found the paper and the press release.

In the interest of journalistic integrity, no. Jupiter does not eat other planets. Not now anyway, and really, not in the past. It’s not hanging out there in our solar system, pulling in large worlds and demolishing them. But back in the planetary formation period of our solar system, Jupiter did have a tendency to pull in kilometer-sized planetesimals.

To find this out, the team analyzed gravitational data collected by Juno, which allowed the team to ‘see’ below the stormy surface to the inner envelope of the planet’s atmosphere. They found more metals in the inner parts of Jupiter’s atmosphere than in the outer layers. Lead author Yamila Miguel explains: There are two mechanisms for a gas giant like Jupiter to acquire metals during its formation: through the accretion of small pebbles or larger planetesimals. We know that once a baby planet is big enough, it starts pushing out pebbles. The richness of metals inside Jupiter that we see now is impossible to achieve before that. So we can exclude the scenario with only pebbles as solids during Jupiter’s formation. Planetesimals are too big to be blocked, so they must have played a role.

The findings in this research mean that Jupiter doesn’t have convection below the surface as previously thought. And it also doesn’t mean that Jupiter eats planets, despite headlines that say otherwise. But hey, the headline caught our attention, and now you know the science behind the story.

More Information

SRON press release (Dutch and English)

“Jupiter’s inhomogeneous envelope,” Y. Miguel et al., 2022 June 8, Astronomy & Astrophysics