WHY DOESN’T EARTH HAVE RINGS?
MOE MBAGO, LONDON
ALAMY X2, SCIENCE PHOTO LIBRARY, GETTY IMAGES ILLUSTRATIONS: DANIEL BRIGHT
All gas giant planets ( Jupiter, Saturn, Uranus and Neptune) in the Solar System have rings, while the terrestrial ones (Mercury, Venus, Earth and Mars) do not. There are two theories about how ring systems develop. They may have formed from leftover material from the formation of the planet, or be the remains of a moon that was destroyed by an impact, or was simply broken apart by the gravitational tugging of its parent.