Stars in reference to earth

Welcome! I am so excited to explore the cosmos with you today, starting with the star that's right in our backyard.

Before we dive into how stars interact with our home planet, I'd love to know a bit about what brings you here today so I can make this session as interesting as possible for you.

I'm looking for a general overview of stars and Earth.

Our Stellar Backyard

Let's start right at the beginning: the closest star to us is the Sun. It is so familiar to us that we sometimes forget it is actually a star—just like the tiny pinpricks of light we see in the night sky. At its core, a is a giant, glowing ball of hot gas, mostly hydrogen and helium, held together by its own gravity. Inside its core, a churning nuclear forge generates a mind-boggling amount of energy, which radiates out into space as light and heat. Even though the Sun looks completely different to us than the stars at night, that's entirely due to how close it is to Earth. While other stars are trillions of miles away, our Sun is right on our cosmic doorstep. Let's look at how it compares to our planet to get a sense of its massive scale.

A scale comparison showing a tiny blue dot for Earth next to a massive yellow arc representing the curvature of the Sun.

This massive difference in scale is what allows the Sun to dominate our sky and exert such a powerful influence on our home planet. Would you like to explore why the Sun is so vital to life on Earth, or should we look at how its distance compares to other stars in the cosmos?

Continue to how far away the Sun is

Let's zoom out to look at the numbers because they are truly mind-boggling. Our Sun is located about —or 93 million miles—away from us.

To put that in perspective, if you could jump in a commercial jet and fly toward the Sun at normal cruising speed, it would take you about 19 years of continuous flight to get there.

Because space is so vast, even light—the fastest thing in the universe—takes time to travel from the Sun to your eyes. Light travels at an incredible speed of 300,000 kilometers per second, yet it still takes about 8 minutes for a beam of solar light to reach Earth. This means when you look outside, you are actually seeing what the Sun looked like 8 minutes ago! It is a real-life form of time travel.

To understand why other stars look like tiny, flickering points of light, we have to compare this distance to our next closest stellar neighbor.