Pictures like this is what hook people to astronomy, right? It looks so majestic and magical, making it hard to believe that something this astounding can exist. Wouldn’t you just want to take a trip to space to see one with your own two eyes?
As many people aren’t aware, if you had the ability to travel to one of these nebulae, it would look different. You may not be able to see it.
Why is that so?
In the universe, there exists an electromagnetic spectrum. This spectrum consists of the following (highest energy to lowest energy): gamma rays, x-rays, UV rays, visible light, infrared waves, microwaves and radio waves.
The human eye can only detect colours that are in the “visible light” range. This includes: red, orange, yellow, green, blue, indigo and violet (aka the colours of the rainbow) and different variations of those colours.
Astronomical objects, such as the Rosette Nebula pictured above (located 5,000 light years from the Earth), give off different forms of electromagnetic radiation. These forms include gamma rays and radio waves. But they give off, if any, very little amounts of visible light. Since our eyes can only detect visible light, we wouldn’t be able to see them very well and their colours wouldn’t be as defined.
Astronomers have to do some editing in order for the pictures to properly turn out how they do. A telescope will take the image with different filters, which will allow different wavelengths (different parts of the electromagnetic spectrum) of light to be seen (the higher the energy, the smaller the wavelength). Once pictures with different wavelengths were taken, the images will be overlapped, the filters combining, to make the amazing images we see today.
So maybe it would be better to just sit and stare admiringly at pictures of nebula on your laptop screen. Too bad we couldn’t see all wavelengths of the electromagnetic spectrum…..
Image Credit & Copyright: Arno Rottal (Far-Light-Photography)