Look up at the night sky with your own eyes, or marvel at pictures of the universe online, and youll see the exact same thing: the inky, abysmal blackness of space, stressed by intense stars, worlds or spacecraft. Why is it black? Why isnt area vibrant, like the blue daytime sky in the world? Surprisingly, the response has little to do with a lack of light. “You would believe that because there are billions of stars in our galaxy, billions of galaxies in the universe and other things, such as worlds, that reflect light, that when we search for at the sky during the night, it would be exceptionally intense,” Tenley Hutchinson-Smith, a college student of astronomy and astrophysics at the University of California, Santa Cruz (UCSC), informed Live Science in an email. “But instead, its actually really dark.” Related: How long is a stellar year?Hutchinson-Smith stated this contradiction, understood in physics and astronomy circles as Olbers paradox, can be described by the theory of space-time expansion– the concept that “due to the fact that our universe is expanding faster than the speed of light … the light from far-off galaxies may be turning and stretching into infrared waves, microwaves and radio waves, which are not detectable by our human eyes.” And since they are undetectable, they appear dark (black) to the naked eye.Miranda Apfel, who is also a college student of astronomy and astrophysics at UCSC, concurred with Hutchinson-Smith. “Stars release light in all colors, even colors not noticeable to the human eye, like ultraviolet or infrared,” she told Live Science. “If we might see microwaves, all of area would radiance.” Apfel stated this is due to the fact that the cosmic microwave background– light energy from the Big Bang that was scattered by electrons and protons existing during the early universe– still fills all of space.Another factor interstellar and interplanetary area appear dark is that area is an almost perfect vacuum. Remember that Earths sky is blue due to the fact that molecules that comprise the environment, including nitrogen and oxygen, spread a great deal of noticeable lights element blue and violet wavelengths from the sun in all instructions, including toward our eyes. Nevertheless, in the absence of matter, light journeys in a straight line from its source to the receiver. Since space is a near-perfect vacuum– implying it has extremely few particles– theres virtually absolutely nothing in the space between planets and stars to scatter light to our eyes. And with no light reaching the eyes, they see black.That said, a 2021 study in The Astrophysical Journal suggests that space might not be as black as researchers originally thought. Through NASAs New Horizons mission to Pluto and the Kuiper Belt, researchers have actually been able to see area without light interference from Earth or the sun. The team sorted through images taken by the spacecraft and deducted all light from known stars, the Milky Way and possible galaxies, as well as any light that may have dripped in from video camera quirks. The background light of deep space, they discovered, was still two times as bright as anticipated. The factors for the extra brightness, which remain unknown, will be the focus of future research studies. Till then, something seems most likely: Space could really well be more “charcoal” than pitch-black. Originally released on Live Science.

Apfel said this is due to the fact that the cosmic microwave background– light energy from the Big Bang that was scattered by protons and electrons existing throughout the early universe– still fills all of space.Another reason interstellar and interplanetary area appear dark is that space is an almost perfect vacuum. Since space is a near-perfect vacuum– indicating it has extremely few particles– theres essentially absolutely nothing in the area between stars and worlds to scatter light to our eyes. And with no light reaching the eyes, they see black.That said, a 2021 study in The Astrophysical Journal suggests that space may not be as black as scientists originally believed. The group sorted through images taken by the spacecraft and subtracted all light from known stars, the Milky Way and possible galaxies, as well as any light that might have leaked in from camera quirks.