Planet Compare - NASA Solar System Exploration
Apr 9, 2026 · 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 | Callisto – NASA Solar System Exploration
Callisto is Jupiter’s second largest moon and the third largest moon in our solar system. It’s about the same size as Mercury. In the past, some scientists thought of Callisto as a boring “ugly duckling …
In Depth | Our Solar System – NASA Solar System Exploration
The planetary system we call home is located in an outer spiral arm of the Milky Way galaxy. Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, …
In Depth | Ganymede – NASA Solar System Exploration
Jupiter’s moon Ganymede is proving to be a fascinating world. Not only is it the largest moon in our solar system, bigger than the planet Mercury and the dwarf planet Pluto, but NASA’s Hubble Space …
In Depth | Sun – NASA Solar System Exploration
NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
Mercury 3D Model – NASA Solar System Exploration
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RPS 3D Viewer - NASA Solar System Exploration
Apr 9, 2026 · 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 | Moons – NASA Solar System Exploration
Of the terrestrial (rocky) planets of the inner solar system, neither Mercury nor Venus have any moons at all, Earth has one and Mars has its two small moons. In the outer solar system, the gas giants Jupiter …
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 Earth that …
Lesson Overview It is challenging to design a scale model of the Solar System where the same scale is used to portray not only the physical sizes of the Sun and planets, but also the distances between …