In Depth | Earth's Moon – NASA Solar System Exploration
Earth's Moon is the only place beyond Earth where humans have set foot, so far. Earth's only natural satellite is simply called "the Moon" because people didn't know other moons existed …
In Depth | Moons – NASA Solar System Exploration
There are hundreds of moons in our solar system – even asteroids have been found to have small companion moons. Of the terrestrial (rocky) planets of the inner solar system, neither Mercury …
By the Numbers | Earth's Moon – NASA Solar System Exploration
The distance from the center of an object to its equator. The outer or uppermost part of a planet, moon, asteroid, comet or other body. The gravitational acceleration experienced at its surface …
Planet Compare - NASA Solar System Exploration
Oct 21, 2025 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
In Depth | Enceladus – NASA Solar System Exploration
Oct 9, 2008 · From gravity measurements based on the Doppler effect and the magnitude of the moon’s very slight wobble as it orbits Saturn, scientists determined that the jets were being …
RPS 3D Viewer - NASA Solar System Exploration
Oct 21, 2025 · Solar System Exploration Our Galactic Neighborhood Solar System Planets Moons Asteroids, Comets & Meteors More
In Depth | Our Solar System – NASA Solar System Exploration
There are more than 200 known moons in our solar system and several more awaiting confirmation of discovery. Of the eight planets, Mercury and Venus are the only ones with no …
In Depth | Titan – NASA Solar System Exploration
Titan is bigger than Earth's moon, and larger than even the planet Mercury. This mammoth moon is the only moon in the solar system with a dense atmosphere, and it’s the only world besides …
In Depth | Io – NASA Solar System Exploration
Jupiter's rocky moon Io is the most volcanically active world in the solar system, with hundreds of volcanoes, some erupting lava fountains dozens of miles (or kilometers) high.
In Depth | Europa – NASA Solar System Exploration
With an equatorial diameter of 1,940 miles (3,100 kilometers), Europa is about 90% the size of Earth’s Moon. So if we replaced our Moon with Europa, it would appear roughly the same size …