Pine Pollen Corona. Water drops are not essential to make a corona, the bright aureole and rings we see around the moon or the sun. Pollen grains shed in billions by spring trees produce excellent coronae. Grains from a single tree variety are same-sized and hence their coronae are sharp and multi-ringed. Unlike water droplets, pollens are non spherical.The grains have air sacs to help disperse them ... The result is anisotropic scattering and oval rings with bright areas.