A brilliant flash of blue, green and white on Saturday night came from a shard of an as yet unidentified comet that was moving around 100,000 miles per hour, experts said. A brilliant flash of blue, green and white on Saturday night came from a shard of an as yet unidentified comet that was moving around 100,000 miles per hour, experts said. Comets, Space and Astronomy, Spain, Portugal, Asteroids, Research NYT > Science