Jupiter’s massive size may have been a surprise to scientists, but new research reveals the planet could have been even larger in its ancient past.
The massive Jupiter has long been considered the largest object in our Solar System, with a mass more than twice that of all other planets combined. However, new research from Caltech and the University of Michigan suggests that Jupiter may have once been even larger, boasting enough volume to fit over 2,000 Earths inside it.
To understand Jupiter’s early evolution, scientists turned their attention to two of its small moons, ‘Amalthea’ and ‘Thebe.’ These moons exhibit unusual orbits that aren’t fully explained by their host’s current size, providing a window into the planet’s past. By analyzing the orbital dynamics of these tiny moons and the planet’s angular momentum, researchers were able to make precise measurements of Jupiter’s size, spin rate, and magnetic conditions around 4.5 billion years ago.
The findings reveal that ‘Jupiter must have had a radius up to 2.5 times greater than it is today,’ with its magnetic field being 50 times more powerful. This dramatic shift in size and magnetic strength has significant implications for our understanding of the Solar System’s architecture, particularly during the critical moment when the protoplanetary disk surrounding the Sun evaporated.
The researchers’ calculations are consistent with the prevailing ‘core-accretion theory describing how giant planets formed.’ According to this theory, giant planets began as heavy, solid cores floating on the farther and colder side of the protoplanetary disk, pulling in lighter gas molecules surrounding them. The findings provide a valuable benchmark for furthering our understanding of the Solar System’s architecture.
The discovery sheds new light on Jupiter’s early evolution and its role in shaping the Solar System. By making precise measurements of primordial Jupiter’s size, spin rate, and magnetic conditions, researchers have established a crucial reference point for reconstructing the evolution of our Solar System. This work has significant implications for our understanding of the Solar System’s architecture and will undoubtedly contribute to ongoing debates about the origins of giant planets.
The study’s findings offer a fascinating glimpse into Jupiter’s ancient past, revealing that this massive planet may have been even larger than we previously thought. By exploring the unusual orbits of ‘Amalthea’ and ‘Thebe,’ researchers have uncovered clues that shed new light on the early phases of planet formation in our Solar System.
