Of the eight planets in our solar system, Jupiter is indubitably the most swole. It is large, with a radius of 43,440 miles (69,911 kilometres). It also has a bit of a rage problem, as the planet’s constantly shifting storms are notoriously chaotic. While the Jovian origin story has always been a bit of a mystery, a new study suggests the weird world got very large very quickly, and not from crushing protein shakes.
Typically, astronomers who’ve used models to estimate Jupiter’s age say it started forming about 10 million years after the birth of the solar system. But after analysing the isotopic composition of 19 meteorites, scientists from the University of Münster and Lawrence Livermore National Lab in California claim that Jupiter’s solid core may have started to form much earlier—about one million years after the dawn of the solar system. For context, the solar system is about 4.5 billion years old, so Jupiter’s been around a long time—certainly the longest of any of the planets in our neighbourhood. The team’s research has been published in the Proceedings of the National Academy of Science (PNAS).
According to the researchers, the material in their meteorites can be traced back to two distinct nebular reservoirs. Although these reservoirs coexisted between one and 3–4 million years after the formation of the solar system, they were spatially separated. The team suggests this is due to the formation of Jupiter, which was already big as hell, even back then. By the team’s estimates, about one million years after the birth of the solar system, Jupiter’s core had swelled to about 20 times Earth’s mass.
“The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disc (a plane of gas and dust from stars) and preventing the exchange of material between the two reservoirs,” Thomas Kruijer, the study’s lead author, said in a statement. “Jupiter is the oldest planet in the solar system, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.”
Estimating Jupiter’s age can help to fill in the gaps in our solar system’s origin story. Our big, mysterious grandpa planet has a lot to teach us about ourselves, and this is just the beginning. [PNAS]