Gaia's Astounding Feat: Decoding Asteroid Interiors with Cosmic Gravitational Whispers

For years, the European Space Agency's (ESA) Gaia mission has been a cosmic cartographer, meticulously mapping the positions, distances, and movements of billions of stars across our Milky Way galaxy with unparalleled precision. Its data has transformed our understanding of galactic structure and evolution.

However, in a groundbreaking new development, Gaia has unveiled an unexpected and extraordinary capability: peering into the hidden hearts of asteroids, the rocky remnants that populate our solar system.

Scientists have discovered that Gaia’s incredible precision, originally designed to measure the minute shifts of distant stars, is sensitive enough to detect the even more subtle gravitational nudges asteroids exert on one another.

These tiny celestial interactions, a delicate dance of masses, cause minuscule deviations in an asteroid's trajectory that were previously impossible to measure with such accuracy. But Gaia's instruments, operating at the very limits of astrometric precision, can now capture these ephemeral wobbles.

This pioneering technique allows researchers to determine an asteroid's mass with unprecedented accuracy.

By combining these mass measurements with observations of the asteroid's size, scientists can calculate its density. Density, in turn, is a critical clue to an asteroid's internal composition and structure – whether it's a solid, monolithic rock, a porous .