Why Is Space Dark

Astronomers determine distances to 18 dwarf galaxies.

Why is space dark. It s perplexed many astronomers since the time of sir edmond halley of comet fame in the 17th century. Light usually travels straight ahead in a line unless it reflects off of something or. You might think that space appears dark at night because that is when our side of earth faces away from the sun as our planet rotates on its axis every 24 hours. Universe today has another explanation.

Space is black to our perception because there are few molecules of matter that can reflect or scatter light like our atmosphere on earth. Why does space look so dark. A few hundred thousand years after the big bang when the first light was able to leap out into space everything in every direction was as bright as the surface of a star. But inside the solar system space is filled with light.

Stars may twinkle up above but the rest is as dark as can be. That s because although starlight gets fainter with distance a simple calculation shows the fading is cancelled out by the ever increasing numbers of stars with distance and should therefore leave space ablaze with light. Hubble looks at light and dark in the universe. The color black usually signals the absence of light.