Neptune's Inner Moons May Be Shattered Remains of Ancient Icy Worlds

Caltech researchers, using NASA's James Webb Space Telescope, have observed three of Neptune's inner moons and found an unexpected signature: clay minerals that only form in the presence of liquid water. These small moons—Larissa, Galatea, and Proteus—appear to be fragments of much larger, ancient icy worlds destroyed long ago. According to the team, Neptune's large moon Triton was likely captured by the planet's gravity after forming elsewhere in the solar system, and that capture event catastrophically destroyed Neptune's original moon system. The debris from the collision eventually reformed into the smaller inner moons we see today. What makes this puzzling: the clay minerals show these fragments came from deep inside objects that contained liquid water, yet no water ice is visible on the moons themselves now. The research essentially exposes the buried interior of ancient icy worlds, normally sealed away from direct observation. The findings were published today in Science Advances.

Listen to this story

Hear this and more stories in a personalized audio briefing.

Open The Chonkerton