If you were to look at the night sky, it could range from a dusty glow to an inky expanse with thousands of twinkling stars, depending on where you are.
On a clear night, estimates suggest that a few thousand stars are visible to the naked eye, but the glare of light pollution from city and small town lights prevents us from getting a view of the cosmos in all its glory. splendor.
In order to describe the amount of light pollution from a particular location, astronomers use the Bortle scale, which ranks visibility from levels one through nine. John Bortle first described it in a 2001 edition of Sky & Telescopean astronomy magazine.
Each level ranks the night sky according to their cosmic views. You can find the Bortle Scale level for your night sky using the interactive map tool at lightpollutionmap.info.
These images show how many more stars you can see in really dark skies, outside of cities, suburbs, and other sources of human light:
What is observable: the Moon, the nearest planets and a handful of the brightest stars
Where to find it in the USA: New York, Las Vegas, Los Angeles
A sky with extremely bright light pollution, found mostly over large cities, turns orange. Although not as potentially harmful as other types of pollution, light pollution can affect human health.
Several studies have indicated that exposure to light at night can disrupt the body’s biological clock, which is linked to health complications including obesity, depression and sleep disturbances.
What is observable: Constellations may be slightly visible
Where to find it in the USA: Boston, Massachusetts; Austin, TX; Indianapolis, Indiana
At level eight, the sky can be so bright from light pollution that you could read on it. To the naked eye, most stars and even constellations will be invisible.
What is observable: the star cluster M44 and the Andromeda galaxy are very indistinct, and the Milky Way is totally or almost completely invisible
Where to find it in the USA: Seattle, Washington; Savannah, Georgia; Salt Lake City, UT
The light pollution in these areas makes the entire sky appear light gray and the Milky Way is effectively invisible.
A 2016 study estimated that even on the clearest night, a third of humanity cannot see the Milky Way.
What is observable: the Andromeda galaxy is only faintly apparent
Where to find it in the USA: Albuquerque, New Mexico; Lincoln, Nebraska; Bloomington, Indiana
At level six, the clouds appear quite bright, and the sky glows a grayish-white. The light pollution in these conditions is very bright.
What is observable: the milky way galaxy may look washed out
Where to find it in the USA: Burlington, Vermont; Santa Fe, New Mexico; Grand Junction, Colorado
Most of us spend our lives at or above this level of the Bortle scale, according to telescope store OPT Telescopes.
At level five, light pollution will be visible in most, if not all, directions. The clouds are brighter than the sky itself, and the Milky Way is faint.
What is observable: the Milky Way, the Triangle Galaxy
Where to find it in the USA: Twin Falls, Idaho; Flagstaff, Arizona; Wind River Indian Reservation, Wyoming
Light pollution is visible in several directions. Under these skies, the sky background begins to appear gray instead of black.
What is observable: the Milky Way galaxy and dense collections of stars such as M4, M5, M15 and M22
Where to find it in the USA: Yosemite National Park, California; Everglades National Park, Florida; Great Smoky Mountains National Park, Tennessee
You can see the Milky Way, but fine detail is gone. Some clouds are illuminated in the direction of the light sources, but the clouds above remain dark.
What is observable: the Milky Way, the Magellanic Clouds
Where to find it in the USA: Cherry Springs State Park, Pennsylvania; Adirondack Park, New York; Joshua Tree National Park, California
The Milky Way is very visible to the naked eye. Skyglow, a haze of light from scattered light sources on the ground, can be faintly apparent along the horizon.
What is observable: the Milky Way, the Andromeda Galaxy, the Orion Nebula
Where to find it in the USA: Big Bend National Park, Texas; Grand Canyon National Park, Arizona; Denali National Park, Alaska
The Level 1 skies offer unobstructed views of the cosmos, comparable to those seen by Galileo. The night sky is full of stars, which makes it more difficult to analyze faint constellations. The Milky Way is so bright that it is capable of casting shadows.
This article was originally published by Business Insider.
Learn more about Business Insider:
#depressing #images #show #dont #night #sky