Asteroid 1865, Cerberus, an Apollo asteroid, was discovered on October 26, 1971 by Lubos Kohoutek at Hamburg-Bergsdorf Observatory in Hamburg, Germany. It has a period of 1 year, 44 days and is about 9/10 of a mile in diameter.
It was named for Cerberus, the multiheaded dog who guarded the gates of the realm of the dead in Greco-Roman mythology and ensured that no one having crossed into Hades would return. Hercules brought him out of Hades as one of his famous Twelve Labors.
A depiction of Cerberus by William Blake
Astrologically, asteroid Cerberus has been linked with exclusive entry, irrevocable or irretrievable entry, not being let back in or out.
The glyph for Cerberus is mine.