Assuming you were travelling through interstellar space.....?

Question

How far would you have to be from Earth before constellations started looking different?

Answer 1

You have a very good question that reflects good visionary thinking. When you look at a certain constellation, you see certain group of stars that seem to be grouped together to form a certain shape. That was the way old astronomers saw the constellations and draw lines between one star and another until they formed a certain shape, and then they named the shape the way they imagined it looked like. For example, when they named the constellation Orion, they saw a great Hunter girded with a sword around him and thus the name of Orion originated. In mythology, they refer to that constellation as: "Behold Orion rise, his arms extended measured half the skies."

Now if you ride in a spaceship and fix your heading toward that constellation, you will soon start to see Orion becoming deformed and after a while you start seeing different constellation grouped together that has nothing to do with the image of Orion. The reason behind that is because the stars that we see from Earth and form the constellation Orion are so far apart from each other but happened to be in that same location in the skies that we observe from Earth. I will give a quick explanation: The star Betelgeuse is so far away from our solar system and much bigger than our sun. Its diameter is estimated to be 460 million miles. The diameter of our sun is 465,000 miles. It is 272 light years away from us and its relative brightness is 0.5 to 1.1 in magnitude. Its absolute brightness is almost 3000 times brighter than our sun. Most of the other stars that form this constellation are double stars or tripple or quadruple ... and so forth, which means if you are traveling in their direction and with a reasonable speed, you will soon start seeing more than one star in the same location that you see on Earth. There are more than 1 quadrillion stars in heaven that have brightness more than 10 in magnitude. All stars having a magnitude of 5 and above cannot be seen by the naked eye. You can just imagine how many stars you will begin to see when you get closer and closer to the constellation Orion without mentioning the great nebula located at the Orion belt. Your question so far has not been answered, but to be exact in answering the question, I should say depending on which constellation you are talking about. You have to travel starting from 4 light years and going upward as much as it may take into space before the image of a certain constellations begins to brake. You can determine the distance yourself by selecting a certain constellation and figuring out what the distance of each star in the selected constellation, and then you begin to realize the distance necessary to travel in space until the image breaks. Just to make the idea so fascinating, if you consider a point in the sky that has no stars, you could find more than 1 billion stars in that location if you travel so fast toward that insignificant point. Not only you may find 1 billion stars, you may find 1 billion galaxies in that same point provided of course that we are talking about infinite space.

Answer 2

That's an interesting question. The apparent motion of the stars due to our movement is called Parallax. The parallax that we observe from orbiting the Sun is rather small, but it is nonetheless measureable (using powerful telescopes).

But how far must we move for the parallax to be easily recognizable to the human eye? Without going through the math, the answer is about a ten thousand astronomical units (AU, the distance from the Earth to the Sun, 100 million km). This is ~1/100 the distance between stars. After travelling this distance, stars will have appeared to move a few degrees on the sky, noticeably distorting the constellations. Unless you actually move several million AU, though, and pass some stars, the constellations will keep their basic shapes.

Answer 3

The distance depends on what Constellations you are talking about.

Answer 4

In inter-stellar space things would change as you progressed.
When you got out to inter-galactic space thing would not change to any extent,as you got farther away the surrounding galaxies would forever stay looking the same.