Most of the hundreds of billions of stars in our galaxy are thought to have planets of their own, and the Milky Way is but one of perhaps 100 billion galaxies in the universe.

The Sun orbits the center of the Milky Way, bringing with it the planets, asteroids, comets, and other objects in our solar system. Our solar system is moving with an average velocity of 450,000 miles …

Our Sun is one of over 100 billion stars in the Milky Way, and our galaxy is just one of countless billions in the universe, each having millions – or billions – of stars of their own.

May 28, 2025 · Our solar system has eight planets, and five dwarf planets - all located in an outer spiral arm of the Milky Way galaxy called the Orion Arm.

Dec 4, 2025 · Our solar system is located in the Milky Way, a barred spiral galaxy with two major arms, and two minor arms. Our Sun is in a small, partial arm of the Milky Way called the Orion Arm, or …

Science Overview Voyage is a 1 to 10-billion scale model of the Solar System that was permanently installed in Washington, D.C., in October 2001. The real Solar System is exactly 10 billion times …

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.

Ganymede is the only moon known to have its own magnetic field – a discovery made by NASA’s Galileo spacecraft in 1996. The magnetic field causes auroras, which are ribbons of glowing, hot, …

Sep 24, 2025 · In celebration of the Hubble Space Telescope’s 35 years in Earth orbit, NASA is releasing an assortment of compelling images recently taken by Hubble, stretching from the planet …

Here's how. Let's assume you are observing another galaxy and discover a Cepheid variable star in that galaxy. Measure its period by timing how long it takes to brighten and dim. You will then have a good …