Saturn's B Ring is the widest and brightest of its main rings. It stretches roughly 25,500 kilometres across, making it broader than the A Ring and C Ring, and its dense ice-rich material reflects sunlight strongly.
The B Ring lies between the inner C Ring and the outer A Ring. The Cassini Division, a broad region of lower ring density, separates the B Ring from the A Ring. Although it appears like an empty gap from Earth, spacecraft observations showed that the division still contains diffuse ring material.
The rings are made mostly of water ice, mixed with smaller amounts of dust and rocky or organic material. The B Ring can look especially bright because it contains dense concentrations of particles and blocks much of the light passing through it. Its visible brightness should not be confused with the overall visual prominence of Saturn's entire ring system, which includes several much fainter rings.
A common mistake is choosing the A Ring because it is the outermost major ring that is easy to identify. The A Ring is prominent, but the B Ring is the larger, brighter and more massive main ring.