Asteroid and dwarf planet
Ceres is the largest asteroid and the first to be discovered, in 1801. Because it is so large (about 590 miles in diameter) and has a spherical shape, it has more recently been classified as a dwarf planet, along with Pluto, Eris, Haumea, and Makemake. For comparison, Pluto is 1430 miles in diameter, and our Moon is 2159 miles in diameter.
The best way to be sure you have located an asteroid is to see it move against the background stars. Its movement can be clearly seen in these two images taken 25 minutes apart.
On this night Ceres was about 340 million miles away in the constellation Pisces and shining at magnitude 9, brighter than all the stars in the field of view.
March 18, 2026