Constellations in 3D

This simulation places the stars of Orion and the Big Dipper at their approximate real distances from Earth. A slider moves smoothly from a flat sky picture to full depth, sight lines run from Earth to each star, and buttons jump to the view from Earth or from the side. Readouts show the nearest and farthest star, their distance ratio and how wide the pattern looks on the sky. Teachers can use it to show that constellations are patterns of line of sight, not groups of neighbors.

• Set Pattern to Orion and drag Flat sky to true depth from 0 to 1.
• Press View from side and compare the nearest and farthest stars.
• Read the Far divided by near readout for Orion and for the Big Dipper.
• Turn on Sight lines from Earth to see how stars line up from our viewpoint.
• Press View from Earth to return to the familiar flat sky pattern.

1. 1Explain that a constellation is a pattern on the sky, not a real group of stars.
2. 2Compare the distances of stars within Orion and the Big Dipper.
3. 3Use a light-year as a unit of distance.
4. 4Describe how a change of viewpoint reveals depth.

Questions teachers ask