Utah Skies: Moons Of Our Solar System

Apr 15, 2021

Credit Dell Vance

April 7, 2021, just before sunrise, Saturn, Jupiter, and a crescent Moon will be visible in the east southeast. The highest bright object is Saturn. Saturn has 82 known moons. Saturn has the most moons in the Solar System. Titan, the second largest moon in the Solar System, is Saturn’s largest moon. It is usually far enough away from Saturn that it is easy to see in most telescopes. In larger telescopes you may even see the smaller moon Rhea.

Moving toward the horizon the brightest object is Jupiter. Jupiter has 79 known moons. The four larger moons of Jupiter are known as the Galilean Moons. Galileo was the first to see these four moons in 1610. He recognized that the moons were satellites of Jupiter and named them. They are named Io, Europa, Ganymede, and Callisto. Ganymede is the largest moon in the Solar System and only slightly larger than Titan. These four moons are easy to pick out in most telescopes and some larger binoculars. 

Our Moon is the next object just above the Eastern Horizon. Our Moon is the fifth largest moon in the Solar System. The crescent moon is easily visible with the naked eye. With binoculars or telescopes, you can find the terminator (where the lighted area meets the shadowed area). The terminator is a great area to see details of crater walls and mountains.

NASA reports there are over 200 moons in our solar system. Every major planet in the solar system has moons except for Mercury and Venus. The dwarf planet Pluto has 5 moons. Many asteroids have moons. Most moons are formed from the dust around the planets. However, a few moons were formed somewhere else and were captured by the larger worlds. The following list shows how many moons each planet has:

Earth: 1

Mars: 2

Jupiter: 79

Saturn: 82

Uranus: 27

Neptune: 14

Pluto: 5

During the Grand Conjunction of Jupiter and Saturn on December 21, 2020, I was able to image Jupiter and Saturn with several of their moons. The image is attached. To get the moons to show up I had to overexpose the planets. Therefore, details of the planet are not visible.