Just how dark is the night sky?
Look up if you step outside on a moonless night; it probably doesn’t appear to be all that dark. A backdrop glow is produced by neighboring streetlights or porch lights, especially if they contain bluish-white LEDs. Most likely, there is so much light pollution in your area that you can only see a few bright stars.
Our skies are so bright that the Milky Way is barely discernible, even in somewhat rural locations. Only approximately 25% of kids in North America and Europe have seen the Milky Way.
You have to go to a really remote area of the planet to escape the light pollution.
The Andean desert in Chile is one of the most distant places. The world’s darkest skies can be seen there if you get an opportunity to visit one of the main observatories.
When there is no moon and the Milky Way is above, you may see a vast sea of stars and shadow constellations along the galactic center’s rainbow brilliance. When your eyes are fully acclimated to the dark, you can see a faint silhouette of the Milky Way there because the skies are so dark.
Even so, the sky is not totally dark. Even in the deepest night, our atmosphere gives out a very slight brightness. It is brought on by cosmic rays and ultraviolet sunshine that ionize Earth’s upper atmosphere.
Although we can’t see this airglow when we gaze up straight at it, it is present and it interferes with telescopes that are stationed on Earth. Even the most advanced telescopes must contend with light pollution.
Therefore, we send telescopes into orbit. The Hubble and Webb telescopes undoubtedly capture a clean vision of the cosmos outside our atmosphere.
Despite how amazing their pictures are, they don’t show the sky at its true darkest. Still a problem is Sunglow. Every speck of the hazy dust that makes up our solar system reflects light back toward the earth. This dust-scattered glow is known as the zodiacal light here on Earth. Even in space, it is visible despite being dim to our senses. Even if the night in interplanetary space is dim, it is not sufficiently dark.
We would need to get beyond the dust, to the furthest point of our Solar System, to gain a true picture of the night sky. far beyond of Pluto’s orbit. That distance has been covered by Pioneers 10 and 11, as well as Voyagers I and II. While we still interact with the Voyagers, we have long since lost touch with the Pioneers, and they are unable to send us any helpful images.
However, a far-off spaceship is able to.
In 2015, the New Horizons spacecraft passed by Pluto and the Kuiper Belt Object Arrokoth. Its cameras are still able to collect data while being twice as far from the Sun.
The New Horizons crew has made an attempt to photograph the universe’s brittle darkness. They pointed New Horizons at a region of the sky that was far from the Milky Way, the Sun, and many prominent stars. The amount of light the camera recorded is then measured.
They discovered that it was darker by an expected amount when they compared that amount to the amount recorded by Hubble’s picture of the dark sky, but there is still a very faint glow that astronomers are unable to explain.
New Horizons measured around twice as much if you estimate the background light you’d anticipate from far-off galaxies going all the way back to the big bang. In an effort to confirm this enigmatic background glow or to glimpse the cosmos in its natural darkness, the team will investigate 15 additional dark places over the course of the next month.
And perhaps the light will shine through the gloomiest sky.
This article was originally published by Universe Today. Read the original article.
