How does space become transparent? The Orion Nebula answers
“Until the gas is completely ionized, visible light can be reflected or absorbed, depending on the orientation of the stars and gas with respect to us. The only way to see through neutral gas is by looking in the infrared, which is sensitive to other features. Once the gas is 100% ionized, it’s 100% transparent, and the entire Universe is revealed.”
The distant nebulae might appear to illuminate the night sky, but this neutral gas is mostly only good for reflecting or absorbing starlight, which obscures the view of all the stars and galaxies lying in the background. But this light-blocking effect is only temporary, as over time, this neutral gas will give way to transparency. All it takes is the energy of the hot, blue stars forming inside, whose ultraviolet radiation will eventually ionize all of the material within it. The last gasps of the neutral gas will appear as Evaporating Gas Globules (EGGs), and when they’re all completely ionized, the starlight from everything beyond will be free to stream towards our eyes unimpeded.
Go get the full story in pictures, video and no more than 200 words on today’s Mostly Mute Monday!