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The Moons of Our Solar System. How many moons are in our solar system?. 1? 9? 61? 159?. 159 and counting!. Moons of the Inner Planets. Mercury = 0. Venus = 0. Earth = 1, The Moon. Mars = 2, Phobos & Deimos. Moons of the Outer Planets.
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How many moons are in our solar system? 1? 9? 61? 159? 159 and counting!
Moons of the Inner Planets Mercury = 0 Venus = 0 Earth = 1, The Moon Mars = 2, Phobos & Deimos
Moons of the Outer Planets Jupiter = 63, including Callisto, Io, Europa, Ganymede Saturn = 56, including Titan, Enceladus, Dione, Pan Uranus = 27, including Ariel, Titania, Puck, Oberon Neptune = 13, including Triton, Galatea, Larissa Pluto = 3, Charon, Nix, Hydra
The Earth’s Moon • 384,403 km (238,857 mi) from Earth & 3,476 km (2,160 mi) in diameter • 27 days, 7 hours, 43 minutes for rotation and revolution around the Earth • Earth’s gravity keeps the same face of the moon permanently turned toward us
The Earth’s Moon • It’s the only other place in the Solar System that humans have visited. • Recently, water ice was discovered at the poles underneath the dusty, cratered surface • A “blue moon” is a second full moon in 1 month, & occurs every few years The Earth’s Moon along with Jupiter & 4 of its moons
The Moons of Mars • Mars has 2 moons: Phobos & Deimos • In Greek, Phobos means “fear” & Deimos means “dread”; they are the sons of Mars, the god of war • These moons are heavily cratered & probably captured objects
The Moons of Mars • Phobos is 27 km (17 mi) wide and completes its orbit of Mars in 8 hours • Deimos, at 14 km (9 mi), is one of the smallest moons in the Solar System Phobos Deimos
The Moons of Jupiter • Jupiter has 63 moons & thousands of small objects orbiting it • Scientists refer to it as a “mini Solar System” Jupiter with its moon, Io
The Moons of Jupiter • In 1610, Galileo was the first person to discover the largest moons of Jupiter: Ganymede, Callisto, Io, and Europa • Since then, several spacecraft have examined these “Galilean Satellites” closely Ganymede Callisto Io Europa
The Moons of Saturn • Saturn has 56 moons • The Cassini spacecraft discovered 12 new moons orbiting the planet in 2005 alone Cassini spacecraft Saturn
The Moons of Saturn • Saturn’s moons vary greatly in size & shape • Titan, the largest moon, contains ingredients that one day may nurture life!
The Moons of Uranus • Uranus has 27 moons • Many of them are icy, without an atmosphere or magnetosphere The rings of Uranus and its many moons
The Moons of Uranus • The 5 largest were discovered in the 19th and 20th centuries: Titania, Oberon, Umbriel, Ariel & Miranda Titania Oberon Umbriel Ariel Miranda (images not to scale)
The Moons of Neptune • Neptune has 13 moons, 3 of which were discovered in 2002, 2 more in 2003 • In 1989, Voyager 2 discovered 6 moons not visible from Earth • All of Neptune’s moons are composed of rock & ice, but little else is known about them
The Moons of Neptune Nereid Proteus • Neptune has 3 larger moons: Triton, Nereid & Proteus • Triton is the only moon in the solar system with a retrograde orbit, and 1 of 3 with an atmosphere Triton Images from Voyager 2 in 1989
The Moons of Pluto • Pluto has 3 moons: Charon, Nix, and Hydra • Charon and Pluto have a mutually synchronous orbit, meaning they always show the same face to each other • For the Greeks, Charon was the boatman who carried dead souls to the underworld, ruled by Pluto Pluto Charon
The Moons of Pluto • At 1,186 km (737 mi), Charon’s diameter is little more than half of Pluto’s; no other moon in our solar system is so close in size to its planet • Charon appears to be covered by water ice, differing from Pluto’s surface of frozen nitrogen, methane & carbon dioxide Hubble Space Telescope image of Pluto (left) & Charon
The Moons of Pluto • In November 2005, astronomers discovered two new moons of Pluto: Nix and Hydra. Both moons are much farther away from Pluto than Charon, and many times smaller. • Nix is named after the Greek goddess of night, Charon’s mother. Hydra is a beast that guarded Pluto’s underworld.
Moons of Our Solar System Earth is not the only planet with a moon. At least 159 moons with craters, volcanoes & other spectacular features exist in our solar system. Which ones are your favorites?