Hi, love this blog! Thank you so much for running it! I have a question about star constellations: do they look the same from the surface of Earth and from the Moon? Thanks!
The big dark looks exactly the same from the Earth or the Moon, except on the Earth, you see the Moon in the say, and on the Moon, you see the Earth in the sky.
(Earthrise, Apollo 8, NASA)Otherwise, the stars are comparatively so much farther away that the stars and constellations look the same from any planet in our solar system. Of course, when you get way out towards Pluto, the Sun starts to look like just a very bright star (still the brightest in the sky), and not the glowing huge deathball of nuclear fusion that it really is.
However, once you start going to other stars, the constellations will start to look very different. Constellations look like they do only from specific places. The stars that make up a constellation may not really be close to each other at all. They only look that way from Earth (or near Earth). Each of those stars may be hundreds - or thousands - of parsecs from each other.
The further you go from our solar system, the more different they start to look. By the time you’re a few dozen light-years away, most of the constellations we know will look different - stretched or skewed. Go around to the ‘side’ of a constellation, and you couldn’t even recognize it.
From our nearest neighboring star system (Alpha, Beta, and Proxima Centauri), our own Sun would be part of the constellation of Cassiopeia.
Here’s a short video that shows several constellations and how they would look from different angles.
There is a great astronomy program - Celestia - that allows you to see what the sky would look like from other stars. I’ve used it in my RPGs to show constellations that are important to the cultures of the people that live on different planets in different stellar systems. It’s a pretty easy program to use, and it’s free. If your story is set in our own galaxy, it can be quite useful.
The constellations in the sky of a planet orbiting another star would be a reflection of that species and cultures ideals, dreams, stories, and mythology - just like the constellations of our night sky.