Crowded field...

This Hubble photo of a random patch of sky is part of a survey called Frontier Fields. It contains thousands of galaxies, including massive yellowish ellipticals and majestic blue spirals. Much smaller, fragmentary blue galaxies are sprinkled throughout the field. The reddest objects are most likely the farthest galaxies. Asteroid trails appear as curved or S-shaped streaks. Asteroids appear in multiple Hubble exposures that have been combined into one image. Of the 20 total asteroid sightings for this field, seven are unique objects.