Many people are not clear about the difference between our Solar System, our Milky Way Galaxy, and the Universe.
Let’s look at the basics.
Our Solar System consists of our star, the Sun, and its orbiting planets (including Earth), along with numerous moons, asteroids, comet material, rocks, and dust. Our Sun is just one star among the hundreds of billions of stars in our Milky Way Galaxy. If we shrink the Sun down to smaller than a grain of sand, we can imagine our Solar System to be small enough to fit onto the palm of your hand. Pluto would orbit about an inch from the middle of your palm.
On that scale with our Solar System in your hand, the Milky Way Galaxy, with its 200 – 400 billion stars, would span North America (see the illustration on the right). Galaxies come in many sizes. The Milky Way is big, but some galaxies, like our Andromeda Galaxy neighbor, are much larger.
The universe is all of the galaxies – billions of them! NASA’s telescopes allow us to study galaxies beyond our own in exquisite detail, and to explore the most distant reaches of the observable universe. The Hubble Space Telescope made one of the deepest images of the universe, called the Hubble Extreme Deep Field (image at the top of this article). Soon the James Webb Space Telescope will be exploring galaxies forming at the very beginning of the universe.
You are one of the billions of people on our Earth. Our Earth orbits the Sun in our Solar System. Our Sun is one star among the billions in the Milky Way Galaxy. Our Milky Way Galaxy is one among the billions of galaxies in our Universe. You are unique in the Universe!
Experience the joys of learning about our Earth and sky
Discovering the Ultimate Source of Energy on Earth: The Sun! (Photo Credit: Warren Rupp Observatory)
We invite you to join the NASA Night Sky Network stargazing community on Facebook and Twitter for sky charts, beautiful images, and lively conversation.
Find star parties held by astronomy clubs in your area quickly using these apps or use the website!
Distant Suns, your personal guide to the cosmos, lists Night Sky Network astronomy club star parties, safe solar gazing events, and lectures in the main navigation bar. Distant Suns is available on iPhone, iPad, Kindle, and NOOK.
SkySafari, a powerful planetarium that fits in your pocket, lists Night Sky Network astronomy club star parties, safe solar gazing events, and lectures in the help menu. SkySafari is available for Android and the iPhone, iPad, and iPod Touch.
Clear skies and happy stargazing!
The NASA Night Sky Network is managed by the Astronomical Society of the Pacific in cooperation with NASA.