By Dave Fuller on
9/3/2015 8:12 PM
Today, I saw this question on the astronomy sub-reddit:
If the Earth is moving at 30 km/s around the Sun, and the Sun is orbiting the center of our galaxy at about 200-250 km/s, and our galaxy is moving relatively to the Local Group where it orbits, and the local group moves around the Virgo Cluster - How do the stars stay so consistent in the sky?
I don't particularly think I'm all that smart when it comes to astronomy. I mean, I know how to find things in the sky. I understand what they are, in a very general sense. I know a lot about telescopes, and a fair amount about how they work. And I understand cosmic scale, which is towards the edge of my understanding.
So when I see someone struggling with a question, I will do my best to respond to it in a way that I'd like to see it answered - that is, give me something I can relate to in the response. It's the only way I'll grasp the concept fully.
So here was my answer to the question (lightly edited for clarity):