Discovery of giant ‘exosatellite’ challenges our notion of what makes a moon

Astronomers have discovered a giant exosatellite orbiting a brown dwarf seventy-three light-years away, per Physics World. This satellite orbits something that orbits a star — just like moons in our solar system — yet at scales with no parallel in our cosmic neighborhood. The discovery, published in Nature, challenges how astronomers define a moon, since the object likely formed through direct gas-cloud collapse rather than the debris-disk assembly that built Earth's moon. Researchers now suspect such exotic systems may be far more common across the galaxy than previously thought.

Listen to this story

Hear this and more stories in a personalized audio briefing.

Open The Chonkerton