The brightest and largest object in our night sky, the Moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate. It also causes tides, creating a rhythm that has guided humans for thousands of years.

2025年1月9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.

2025年1月9日 · 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 – in its orbit.

It’s about 93 million miles (150 million kilometers) from Earth and it’s our solar system’s only star. Without the Sun’s energy, life as we know it could not exist on our home planet. From our vantage point on Earth, the Sun may appear like an unchanging source of light and heat in the sky.

The star nearest to the planet Earth is the sun. The sun’s diameter is 1.4 million kilometers and its distance from Earth is 150 million kilometers. But what do numbers that big really mean? To get an idea of size, use a grapefruit to represent the sun. Set it down and walk a dozen steps away. Turn around and

2025年1月9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.

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.

Pluto orbits the Sun about 3.6 billion miles (5.8 billion km) away on average, about 40 times as far as Earth, in a region called the Kuiper Belt.

Jupiter is a gas giant and so lacks an Earth-like surface. If it has a solid inner core at all, it’s likely only about the size of Earth.

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.