How high does the sky go? If you’ve ever wondered how far up the sky goes, or wondered just how many stars we can see, here’s a quick guide to answer those questions and more.

The height of the sky is essentially infinite, as there is no end to space itself. But let’s start with what we know: The edge of our solar system is about 8 light hours from Earth, which means that light takes that long to reach us from there. So if we’re looking up at night and see something that’s 8 light hours away, it must be in space — not just above Earth’s atmosphere but also beyond it altogether.

Our solar system is only one star among many billions in our galaxy (called the Milky Way). And our Milky Way galaxy itself is only one among hundreds of billions in our universe — and the universe itself isn’t even close to being the largest thing we know of! In fact, some physicists think there may be an infinite number of universes out there too.

Last modified: September 20, 2022