1. Moons Orbit Planets
2. Moons Orbiting Moons
3. Moon's Orbit Diagram
4. Moons Orbiting Mars

The animations on this page illustrate the Moon’s orbit and its role in lunar and solar eclipses. A solar eclipse happens when the Moon’s shadow falls on the Earth, while a lunar eclipse happens when the Earth’s shadow falls on the Moon. Eclipses can only happen at New and Full Moon, when the Earth, Moon, and Sun are all in a straight line. The Moon’s orbital period can be estimated by considering the Moon as a satellite of the Earth and using a scale drawing, e.g. The drawing produced in the experiment: Sketching a satellite orbit and predicting its period. The Moon's distance from the Earth is about 60 Earth-radii.

Do you know all 219 moons (so far) of the planets in our solar system? Well here they are! Every so often new moons are discovered for the outer planets and the dwarf planets. Number in parentheses() is the magnitude.

☿ Mercury moons = 0

Mercury is too close to the Sun to hold on to a moon.

♀ Venus moons = 0

Venus may have had a moon in the distant past, which collided with another object and then impacted Venus.

♁ Earth moons = 1

Earth also has several quasi-satellites - asteroids 2020 CD3 and 2020 HO3 being the closest with the most stable temporary orbits.

♂ Mars moons = 2

Both moons of Mars may be captured asteroids. Deimos and Phobos are difficult to see except in very large telescopes due to being so close to Mars.

- ASTEROID BELT REGION -

⚳ Dwarf Ceres moons = 0

Dwarf Hygiea moons = 0

Ceres and Hygiea are the only dwarf planets located in the asteroid belt and have no moons surprisingly. A number of smaller asteroids (also called minor planets) do have moons, but they are all too faint to see in any amateur telescope.

Notable asteroids with moons include:

Sylvia with 2 moons Romulus & Remus; Eugenia with 2 moons Petit-Prince & S2004; Daphne with moon Peneius, Kalliope with moon Linus; Minerva with 2 moons Aegis & Gorgoneion; Kleopatra with 2 moons Alexhelios & Cleoselene; and Ida with moon Dactyl.

- OUTER SYSTEM REGION -

♃ Jupiter moons = 79

Known moons of Jupiter are listed in order of size. The first four moons listed, the Galilean moons, are visible in binoculars. Jupiter may have 600 moons total, but most of these are very small.

♄ Saturn moons = 82

Moons of Saturn are listed in order of size. The first seven moons are viewable using a telescope, and the largest moon Titan, is visible through good binoculars. Saturn also has hundreds to thousands of moonlets embedded in its ring system.

Aegir

Greip

S/2006 S 1

S/2004 S7

S/2004 S27

Jarnsaxa

Farbauti

S/2004 S12

S/2007 S2

S/2004 S23

S/2004 S26

S/2004 S29

S/2004 S32

Methone

Moons Orbit Planets

S/2004 S38

S/2004 S21

S/2004 S24

S/2004 S36

♅ Uranus moons = 27

Moons of Uranus are listed in order of size. The first four are visible in medium to large (8-12 inch) telescopes.

♆ Neptune moons = 14

Moons of Neptune are listed in order of size. Triton is visible using a medium to large (8-12 inch) telescope. Triton is believed to be a dwarf planet from the Kuiper Belt captured by Neptune.

- KUIPER BELT REGION -

♇ Dwarf Pluto moons = 5

Moons of Pluto are listed in order of size. Pluto and Charon are considered a binary dwarf planet system. None of the moons are visible in any amateur telescope.

Dwarf Orcus moons = 1

Dwarf Salacia moons = 1

Dwarf Haumea moons = 2

Dwarf Quaoar moons = 1

Dwarf Makemake moons = 1

Dwarf Varda moons = 1

Dwarf Gonggong moons = 1

Dwarf Eris moons = 1

- INNER OORT CLOUD REGION -

Planets here are in very elongated orbits that go from the Kuiper Belt out to the inner edge of the Oort Cloud. Several dwarf planets out there are believed to be perturbed by Planet 9, thought to be a mini-Neptune planet at 10X Earth mass. It's existence is not yet confirmed.

Moons Orbiting Moons

Two things are infinite: the universe and human stupidity;
and I'm not sure about the universe. -- Albert Einstein

Moon's Orbit Diagram

The moon is really just a large piece of rock, which was caught in the Earth's gravitational field. Because the moon has a smaller mass than the Earth, 7.35 × 10²² kg compared to 5.98 × 10²⁴ kg, the moon orbits around the Earth, making the moon Earth's satellite. In fact, the moon is the Earth 's one and only natural satellite.

So how was the diameter of the moon's orbit determined? One possible way would be finding the Earth-Moon distance. To find the Earth-Moon distance, scientists could use a RADAR laser, in which they can fire electromagnetic waves or em waves at the moon and time how long it takes for the em waves to travel to the moon and back. Since em waves always travel at the speed of light (3 × 10⁸ m/s), and the time can be measured, one can use the equation v = s/t or s = vt, but don't forget to divide the measured time or the calculated distance by 2, as the em waves traveled twice the distance. The moon's distance from the Earth varies from 360,000 km to 406,000 km, making the mean distance from the Earth 384,000 km. Since its mean distance from the Earth is 384,000 km, the average length of the moon's orbit's diameter is 768,000 km.

Is the moon really moving farther away from the Earth? Yes, it is. The moon is moving about 3.8 cm farther away from the Earth every year. This occurs because of tidal interactions. The moon's gravitational force pulls on the Earth making it bulge ar the face of the Earth the moon is facing. These are called 'tidal bulges'. The tidal bulges would affect the force of gravity on the moon, as the bulge would have a greater gravitational pull on the moon than the center of the Earth. And since the Earth rotates faster than the moon orbits, the tidal bulges would move ahead of the moon and pull the moon towards the tidal bulge causing the moon to speed up and move ahead in its orbit. Note: The moon is only moved very little by this in a day, so don't get crazy.

Moons Orbiting Mars

Collin Tam -- 2005