The Sun is a 4.5 billion-year-old yellow dwarf star – a hot glowing ball of hydrogen and helium – at the center of our solar system. 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 …

2020年5月18日 · Light years also provide some helpful perspective on solar system distances: the Sun is about 8 light minutes from Earth. (And yes, there are also light seconds!)

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.

From an average distance of 93 million miles (150 million kilometers), Earth is exactly one astronomical unit away from the Sun because one astronomical unit (abbreviated as AU), is the distance from the Sun to Earth. This unit provides an easy way to quickly compare planets' distances from the Sun.

2019年3月12日 · Two kinds of light show up in STEREO images: light from the Sun’s blazing outer atmosphere — called the corona — and light reflected off all the dust floating through space. The sunlight reflected off this dust, which slowly orbits the Sun, is …

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 · Ulysses was the first spacecraft to explore the Sun from a unique polar orbit.

The solar wind forms from systems of electrical currents within the sun's corona, the outermost layer of the sun's atmosphere, and behaves like an electrically conducting fluid. These incredibly dilute, superheated solar wind gases reach millions of miles into space.

2017年6月12日 · The sun is a star and a star doesn't have a solid surface. Rather, it's a ball of ionized gas 92.1% hydrogen (H2) and 7.8% helium (He) held together by its own gravity. NASA's Solar Dynamic Observatory keeps a steady watch on the sun.

The corona is synchronized with the solar activity cycle, changing shape from a jagged ring around the sun during the peak of the cycle to wispy plumes and streamers that reach millions of miles into space at the end of the cycle.