In Depth | Our Solar System – NASA Solar System Exploration
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.
In Depth | Sun – NASA Solar System Exploration
NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
News - NASA Solar System Exploration
Oct 7, 2021 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
Planet Compare - NASA Solar System Exploration
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.
In Depth | Europa – NASA Solar System Exploration
If it can be demonstrated that life formed independently in two places around the same star, it would then be reasonable to suggest that life springs up in the universe fairly easily once the …
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.
Solar System Exploration
Sep 30, 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 …
In Depth | 1P/Halley – NASA Solar System Exploration
NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
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 …
About the Planets - NASA Solar System Exploration
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.