448 known moons and counting. And Pluto still gets a card.
🔭This number moves. Moon counts come from the International Astronomical Union's official registry, but small outer moons are still being discovered. Saturn alone gained dozens in recent survey batches. Counts below reflect confirmed moons as of August 2026.
The Count, At a Glance
Body
Moons
Headline moon
☿️ Mercury
0
None
♀️ Venus
0
None
🌍 Earth
1
The Moon
♂️ Mars
2
Phobos
🪐 Jupiter
~101
Europa
🪐 Saturn
~292
Titan
⛢ Uranus
29
Miranda
🔵 Neptune
18
Triton
🌑 Pluto
5
Charon
Total
~448
N/A
☿️ Mercury0moons
Too close to the Sun. Any moon that formed or wandered nearby would either get pulled away by solar tides or fall into Mercury outright; the Sun's gravity dominates that entire neighborhood.
♀️ Venus0moons
Same story, less extreme. Venus's slow, backwards rotation and the Sun's tidal pull make a long-term stable moon very unlikely; models suggest any moon it once had would have spiraled back into the planet within tens of millions of years.
🌍 Earth1moon
Formed ~4.5 billion years ago, likely from debris after a Mars-sized body (nicknamed Theia) slammed into the young Earth.
🌕 The MoonStabilizes Earth's axial tilt, which keeps our seasons predictable rather than chaotic. Drives ocean tides. Slowly moving away (~3.8 cm/year), gradually lengthening our day.
♂️ Mars2moons
Small, lumpy, and almost certainly captured asteroids rather than moons that formed alongside Mars.
🪨 PhobosOrbits so fast it rises and sets twice a day in the Martian sky. It's spiraling inward and will eventually crash into Mars or shred into a ring, in roughly 30–50 million years.
🪨 DeimosSmaller and farther out than Phobos, slowly drifting away from Mars instead of toward it.
🪐 Jupiter~101moons
Most are small, irregular, captured rocks, but the four big ones, spotted by Galileo in 1610, were the first proof that something didn't orbit Earth. That observation helped break the geocentric model of the universe.
🌋 IoThe most volcanically active body in the solar system, squeezed and heated by Jupiter's gravity like a stress ball.
🧊 EuropaAn icy shell over a liquid subsurface ocean. One of the top targets in the search for life beyond Earth. NASA's Europa Clipper is en route to study it.
🌑 GanymedeThe largest moon in the solar system (bigger than Mercury) and the only moon with its own magnetic field.
🌑 CallistoAncient and heavily cratered, its surface hasn't changed much in billions of years, a frozen record of the early solar system.
🪐 Saturn~292moons
More moons than any other planet, by a wide margin; most are tiny irregular moons found in recent deep-survey batches. The handful of large ones do the interesting work.
☁️ TitanThe only moon with a substantial atmosphere (thicker than Earth's) plus rivers and lakes of liquid methane and ethane. NASA's Dragonfly drone mission is headed there.
💦 EnceladusGeysers of water ice erupt from its south pole, feeding Saturn's E ring. A subsurface ocean with hydrothermal activity makes it another leading astrobiology target.
🎯 MimasOne giant impact crater gives it an unmistakable "Death Star" look.
🐑 Pan & DaphnisTiny "shepherd moons" that orbit inside gaps in the rings, gravitationally carving and maintaining those gaps as they go.
⛢ Uranus29moons
Uranus's moons break tradition: instead of Greek or Roman mythology, they're named after characters from Shakespeare and Alexander Pope.
🌗 MirandaWildly jumbled terrain, including a cliff face roughly 20 km high (Verona Rupes), possibly the result of being shattered and gravitationally reassembled.
🌕 Titania & OberonThe largest of the bunch, icy, with canyons hinting at past geologic activity.
🔵 Neptune18moons
Neptune's moon story is really a one-moon story: Triton dominates almost everything interesting about the system.
🌀 TritonOrbits backward relative to Neptune's own rotation; strong evidence it's a captured Kuiper Belt object, a relative of Pluto. Has active nitrogen geysers despite being one of the coldest objects ever measured, and is slowly spiraling toward a future breakup.
🌑 Pluto5moons
Reclassified as a dwarf planet in 2006; it never moved, the definition just got more specific. Still gets counted here, mnemonic and all.
🌑 CharonAbout half Pluto's diameter, big enough that the two orbit a shared center of mass in open space between them. Often called a binary dwarf-planet system. Both bodies are tidally locked to each other, permanently showing the same face.
✨ Styx, Nix, Kerberos, HydraFour small outer moons, discovered between 2005 and 2012 as New Horizons was being planned and flown past the system.