In Depth | Our Solar System – NASA Solar System Exploration
Nearest to the Sun, only rocky material could withstand the heat when the solar system was young. For this reason, the first four planets – Mercury, Venus, Earth, and Mars – are …
Mars By the Numbers - NASA Solar System Exploration
Oct 21, 2025 · Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited entirely by robots.
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.
RPS 3D Viewer - NASA Solar System Exploration
Oct 21, 2025 · NASA Solar System Exploration Our Galactic Neighborhood Solar System Planets Moons Asteroids, Comets & Meteors
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 …
In Depth | Asteroids – NASA Solar System Exploration
The orbits of asteroids can be changed by Jupiter's massive gravity – and by occasional close encounters with Mars or other objects. These encounters can knock asteroids out of the main …
Bibliography - NASA Solar System Exploration
Apr 23, 2024 · 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 | Phobos – NASA Solar System Exploration
It orbits Mars three times a day, and is so close to the planet's surface that in some locations on Mars it cannot always be seen. Phobos is nearing Mars at a rate of six feet (1.8 meters) every …
Events | Solar System Ambassadors - NASA Solar System Exploration
May 18, 2023 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
The Sun By the Numbers - NASA Solar System Exploration
Oct 21, 2025 · The Sun is the star at the heart of our solar system. Its gravity holds the solar system together, keeping everything – from the biggest planets to the smallest bits of debris – …