Scientists find remains of cannibalized baby planets in Jupiter's cloud-covered belly

[Elderberry]

Space.com by Harry Baker 6/20/2022

The finding settles a long-standing debate about the gas giant's formation.

Jupiter's innards are full of the remains of baby planets that the gas giant gobbled up as it expanded to become the behemoth we see today, scientists have found. The findings come from the first clear view of the chemistry beneath the planet's cloudy outer atmosphere.

Despite being the largest planet in the solar system, Jupiter has divulged very little about its inner workings. Telescopes have captured thousands of images of the swirling vortex clouds in the gas giant's upper atmosphere, but these Van Gogh-esque storms also act as a barrier blocking our view of what's below.

"Jupiter was one of the first planets to form," in the first few million years when the solar system was taking shape around 4.5 billion years ago, lead researcher Yamila Miguel, an astrophysicist at Leiden University in The Netherlands, told Live Science. However, we know almost nothing for certain about how it formed, she added.

In the new study, researchers were finally able to peer past Jupiter's obscuring cloud cover using gravitational data collected by NASA's Juno space probe. This data enabled the team to map out the rocky material at the core of the giant planet, which revealed a surprisingly high abundance of heavy elements. The chemical make-up suggests Jupiter devoured baby planets, or planetesimals, to fuel its expansive growth.

Growing a gas giant

Jupiter may predominantly be a ball of swirling gas today, but it started its life by accreting rocky material — just like every other planet in the solar system. As the planet's gravity pulled in more and more rocks, the rocky core became so dense that it started attracting large amounts of gas from far distances — predominantly hydrogen and helium left over from the sun's birth — to form its enormous gas-filled atmosphere.

There are two competing theories about how Jupiter managed to collect its initial rocky material. One theory is that Jupiter accumulated billions of smaller space rocks, which astronomers nickname pebbles (although these rocks are likely closer in size to boulders rather than actual pebbles).

More: https://www.space.com/jupiter-ate-baby-planets-while-growing