NGC 3942
NGC 3942 is a spiral galaxy in the constellation Crater about 175 million ly from Earth. It spans roughly 68,000 ly, about 68% of our Milky Way's width. The light reaching us tonight left it about 175 million years ago.
Illustration from its catalogued shape, not a photograph
Because its light is 175 million ly from home, you are seeing NGC 3942 as it looked roughly 175 million years ago. The photons left before that much of history had passed, and are only now reaching us. This distance is estimated from the galaxy's redshift, so the lookback time is approximate.
apartNGC 3836 NED02Spiral17 million ly
apartNGC 4114Spiral22 million ly
apartNGC 3711Spiral22 million ly
apartNGC 3660Barred spiral23 million ly
apartNGC 4177Spiral25 million ly
apart
Source: structural data (position, morphology, brightness, redshift) from OpenNGC (CC BY-SA). Recession velocity from RC3 (de Vaucouleurs et al. 1991, via NASA/HEASARC, public domain). Distance computed by gravityfinder from redshift via Hubble's law (H0 = 70 km/s/Mpc).