In Depth | Our Solar System – NASA Solar System Exploration
Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids.
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.
What is a Planet? | Planets – NASA Solar System Exploration
Some astronomers argued that location (context) is important, especially in understanding the formation and evolution of the solar system. One idea is to simply define a planet as a natural object in space that is massive enough for gravity to make it approximately spherical.
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.
Overview | Mars - NASA Solar System Exploration
Mars is the fourth planet from the Sun – a dusty, cold, desert world with a very thin atmosphere. Mars is also a dynamic planet with seasons, polar ice caps, canyons, extinct volcanoes, and evidence that it was even more active in the past.
RPS 3D Viewer - 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 | Jupiter – NASA Solar System Exploration
Jupiter is the fifth planet from our Sun and is, by far, the largest planet in the solar system – more than twice as massive as all the other planets combined. Jupiter's stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium.
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 nor Venus have any moons at all, Earth has one and Mars has its two small moons.
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.
In Depth | Ceres – NASA Solar System Exploration
When NASA's Dawn arrived in 2015, Ceres became the first dwarf planet to receive a visit from a spacecraft. Called an asteroid for many years, Ceres is so much bigger and so different from its rocky neighbors that scientists classified it as a dwarf planet in 2006.