Part of Hall of the Universe.
The observable universe contains as many as 100 billion galaxies and extends a billion light-years in every direction.
In This Section
Exhibit Formation and Evolution of the Universe Our Milky Way Galaxy was once thought to comprise the entire known universe. Today our universe encompasses many billions of galaxies,... Exhibit Dimming Starlight Telescopes can easily zoom in on a star. But to see a dim object next to a star, such as a planet, astronomers need to block out... Exhibit What is the Universe? The universe is all the matter, energy, and space that exist. We can observe only a part of it - the observable universe. Exhibit Universality of Physical Laws All parts of the universe are subject to the same simple laws of nature that we find here on Earth. Exhibit The Big Bang The Big Bang is the scientific description of the origin of the cosmos. Exhibit Evolution of the Universe Galaxies form and evolve within an expanding and cooling universe. Because light takes billions of years to cross the cosmos, we... Exhibit Our View of the Universe When we look out into space, we also look back into time. Exhibit What are Active Galaxies? An active galaxy emits up to thousands of times more energy than a normal galaxy.