An interstellar cloud is generally an accumulation of gas, plasma, and dust in our and other galaxies. Neutral and ionized clouds are sometimes also called diffuse clouds. An interstellar cloud is formed by the gas and dust particles from a red giant in its later life.

In astronomy, the interstellar medium (ISM) is the matter and radiation that exist in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays.

A nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova.

So when you see a diffuse, reddish glow coming from outer space, that’s evidence of hydrogen gas surrounding hot, young stars. That’s why the Eagle Nebula looks red to our eyes, and that’s even why huge regions of some spiral galaxies appear red: that’s hydrogen gas in regions that are currently forming new, hot stars!

Space emits a range of wavelengths of light, some we can see others we can’t. The majority of emissions are of red and blue light which are easily visible to the human eye but there are also UV, X-rays and gamma rays which are invisible.

3 Answers. This absorption requires light from the red region of the spectrum (~630 nm). If red light is absorbed , then blue light is transmitted or reflected and this gives rise to the blue color associated with liquid oxygen.

pale blue

white

Maybe you’ve heard that blood is blue in our veins because when headed back to the lungs, it lacks oxygen. But this is wrong; human blood is never blue. The bluish color of veins is only an optical illusion. Blue light does not penetrate as far into tissue as red light.

colorless

Blood plasma is a yellowish liquid component of blood that holds the blood cells of whole blood in suspension. It is the liquid part of the blood that carries cells and proteins throughout the body. It makes up about 55% of the body’s total blood volume.

Dark Purple or Blue Period Blood If you’re seeing dark, clotted blood in your panties, you may have too much estrogen in your system. Don’t hit the panic button — this is another off color that can be fixed with dietary adjustments.

Healthy period blood typically varies from bright red to dark brown or black. Blood or discharge that is orange or grey may indicate an infection. Women who experience bleeding during pregnancy should see a doctor or obstetrician for an evaluation.

In most cases, the variation from bright red to dark red to brown has something to do with the flow and time the blood has been in the uterus. Your flow may be faster at the beginning of your period and trail off toward the end. You may have dark red blood after laying down for a long time, too.