Ask Ethan: How do scientists color the Universe? | by Ethan Siegel | Starts With A Bang! | Nov, 2024
When we see pictures from Hubble or JWST, they show the Universe in a series of brilliant colors. But what do those colors really tell us?
For just a moment, I want you to close your eyes and think about the most famous, most spectacular images of the Universe that you’ve ever seen. Did you picture planets or moons within our Solar System? Perhaps you thought of nebulous regions of gas, where new stars are forming inside. Maybe a snapshot of a recently deceased star, such as a planetary nebula or a supernova remnant, is what best captured your imagination. Alternatively, maybe you thought about glittering collections of stars or even entire galaxies, or — my personal favorite — a deep-field view of the Universe, complete with galaxies of all different sizes, shapes, colors and brightnesses.
These full-color images aren’t necessarily what your limited human eyes would see, but are instead color-coded in such a way that they reveal a maximal amount of information about these objects based on the observations that were acquired. Why do scientists and visual artists make the choices that they do? That’s what Elizabeth Belshaw wants to know, writing in to ask:
“When we see stars or galaxies from Hubble and Webb, they are in…