Hubble Caldwell 33 V3
This Hubble image focuses on a tiny tendril in Caldwell 33, the Eastern Veil Nebula. By comparing this Hubble image taken in 1997 with an old ground-based photograph from 1953, scientists measured how far the shock front has moved and used that information to estimate the nebula’s age.
Credits: ESA & Digitized Sky Survey (Caltech)