NGC 3042

NGC 3042 is a lenticular galaxy in the constellation Sextans about 175 million ly from Earth. It spans roughly 52,000 ly, about 52% of our Milky Way's width. The light reaching us tonight left it about 175 million years ago.

Because its light is 175 million ly from home, you are seeing NGC 3042 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.

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).