The Colors of the Cosmos

Nov 22, 2017

Every month Jean Creighton comes down to the studio from her usual haunt in the Manfred Olson Planetarium to tell us stories about the cosmos. Today we talk about color, or lack of it, in the universe:

"You see these beautiful nebulae with all these colors and in your heart you think, 'Oh, just imagine looking through my spacecraft at that.'" says Creighton. "Well, you wouldn't see that. Most of the gas, if you were close enough to it, would be so diffuse there wouldn't be enough light for our eyes to capture. Remember, you're seeing light from literally hundreds of light years of material."

According to Creighton, scientists assign colors to different parts of the black and white images that telescopes like the Hubble produce. "Where are the hot spots? Or where is it densest?"  she asks. Each density layer gets a color assigned to it and those colors allow scientists to look at multiple layers at the same time. (You can see how one composite was made in the NASA video below.)

But to make things more complex, we can't see anything in either the ultraviolet or the infrared part of the spectrum. So those beautiful pictures we see of say, the Butterfly Nebula pictured above, have to be artistically enhanced in the color spectrum we can see. Creighton says making that image appealing can be a challenge.

"It’s probably not hard to make a nebula look otherworldly and odd, as opposed to, 'oh, look at that cool place that I could almost touch,'" she explains. "You want [the picture] to be awesome, but you also want it to be a little familiar."

We think it's a pretty good job of being both.