In Depth | Our Solar System – NASA Solar System Exploration
Of the eight planets, Mercury and Venus are the only ones with no moons. The giant planets Jupiter and Saturn lead our solar system’s moon counts. In some ways, the swarms of moons around these worlds resemble mini versions of our solar system.
In Depth | Sun – NASA Solar System Exploration
The Sun is the largest object in our solar system. Its diameter is about 865,000 miles (1.4 million kilometers). Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest bits of debris in orbit around it.
What is a Planet? | Planets – NASA Solar System Exploration
Defining the term planet is important, because such definitions reflect our understanding of the origins, architecture, and evolution of our solar system. Over historical time, objects categorized as planets have changed.
Planet Compare – NASA Solar System Exploration
2024年11月20日 · 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 | Earth – NASA Solar System Exploration
While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with liquid water on the surface. Just slightly larger than nearby Venus, Earth is the biggest of the four planets closest to the Sun, all of which are made of rock and metal.
About Us - NASA Solar System Exploration
2024年11月20日 · We provide the public with reliable, accurate, up-to-date information about the planets, moons, asteroids, comets and everything else in our solar system. We also provide a complete historical record of deep space exploration.
Mars By the Numbers – NASA Solar System Exploration
2024年11月20日 · Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited entirely by robots.
Neptune By the Numbers – NASA Solar System Exploration
2024年5月16日 · Neptune is the eighth and most distant planet from the Sun. It’s the fourth largest, and the first planet discovered with math.
In Depth | Neptune – NASA Solar System Exploration
Dark, cold, and whipped by supersonic winds, ice giant Neptune is the eighth and most distant planet in our solar system. More than 30 times as far from the Sun as Earth, Neptune is the only planet in our solar system not visible to the naked eye.
Pluto By the Numbers – NASA Solar System Exploration
2024年5月16日 · Pluto was once our solar system's ninth planet, but has been reclassified as a dwarf planet. It's located in the Kuiper Belt.