Overview

• A new study published in *Nature Astronomy* confirms that Jupiter had a radius twice its current size about 3.8 million years after the first solid material formed in the solar system.
• At that time, Jupiter's volume exceeded that of 2000 Earths, and its magnetic field was approximately 50 times stronger than it is today.
• Researchers Konstantin Batygin and Fred C. Adams analyzed the inclined orbits of Jupiter’s small moons, Amalthea and Thebe, to reconstruct the planet’s early dimensions and properties.
• Jupiter’s contraction over billions of years was driven by gas cooling, the loss of its surrounding dust disk, and its own gravitational forces, which also accelerated its rotation and weakened its magnetic field.
• Despite its shrinkage, Jupiter remains the largest planet in the solar system and continues to play a critical role in protecting Earth by deflecting or capturing potentially dangerous asteroids.