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The term '''night sky''' refers to the [[sky]] as seen at night. The term is usually associated with [[astronomy]], with [[reference]] to views of [[celestial]] bodies such as [[stars]], the [[Moon]], and [[planets]] that become visible on a [[clear]] night after the [[Sun]] has set. Natural [[light]] sources in a night sky include moonlight, starlight, and airglow, depending on location and [[timing]]. [[Weather]] phenomenon such nighttime thunderstorms can dominate the [[sky]], and transient [[events]] such as a [http://en.wikipedia.org/wiki/Great_comet great comet].
The night sky and [[studies]] of it have a historical place in both [[ancient]] and [[modern]] [[cultures]]. In the [[past]], for instance, [[farmers]] have used the state of the night sky as a [[calendar]] to determine when to plant crops. Many [[cultures]] have drawn [http://en.wikipedia.org/wiki/Constellation constellations] between stars in the sky, using them in association with [[legends]] and [[mythology]] about their [[deities]].
Otherwise, [[Astrology]] is generally based on the [[belief]] that [[relationships]] between heavenly bodies [[influence]] or convey [[information]] about [[events]] on [[Earth]]. The [[scientific]] study of the night sky and bodies observed within it, meanwhile, takes place in the [[science]] of astronomy.
The visibility of celestial objects in the night sky is affected by [http://en.wikipedia.org/wiki/Light_pollution light pollution]. The [[presence]] of the [[Moon]] in the night sky has historically hindered astronomical [[observation]] by increasing the amount of ambient lighting. With the advent of [[artificial]] light sources, however, light pollution has been a growing [[problem]] for viewing the night sky. Special filters and modifications to light fixtures can help to alleviate this problem, but for the best seeing both [[professional]] and [[amateur]] optical astronomers seek viewing sites located far from major urban areas.
On [[clear]] [[dark]] nights in unpolluted areas, when the [[moon]] is thin or below the [[horizon]], a band of what looks like white dust, the Milky Way, can be seen.
Shortly after sunset and before sunrise, [[artificial]] [[satellites]] often look like [[stars]] - similar in brightness and size, but different because they move relatively quickly; those that fly in near-earth orbit cross the sky in a couple of minutes. Some [[satellites]] (including [http://en.wikipedia.org/wiki/Space_junk space junk]) appear to blink or have a periodic fluctuation in brightness because they are [[rotating]].
[[Meteors]] (commonly known as shooting stars) streak across the [[sky]] very infrequently. During a meteor shower, they may [[average]] one a minute not at regular intervals, but otherwise their [[appearance]] is a [[random]] [[surprise]]. The occasional meteor will make a bright, fleeting streak across the [[sky]], and they can be very bright in comparison to the night sky.[http://en.wikipedia.org/wiki/Night_sky]
[[Category: Astronomy]]
The term '''night sky''' refers to the [[sky]] as seen at night. The term is usually associated with [[astronomy]], with [[reference]] to views of [[celestial]] bodies such as [[stars]], the [[Moon]], and [[planets]] that become visible on a [[clear]] night after the [[Sun]] has set. Natural [[light]] sources in a night sky include moonlight, starlight, and airglow, depending on location and [[timing]]. [[Weather]] phenomenon such nighttime thunderstorms can dominate the [[sky]], and transient [[events]] such as a [http://en.wikipedia.org/wiki/Great_comet great comet].
The night sky and [[studies]] of it have a historical place in both [[ancient]] and [[modern]] [[cultures]]. In the [[past]], for instance, [[farmers]] have used the state of the night sky as a [[calendar]] to determine when to plant crops. Many [[cultures]] have drawn [http://en.wikipedia.org/wiki/Constellation constellations] between stars in the sky, using them in association with [[legends]] and [[mythology]] about their [[deities]].
Otherwise, [[Astrology]] is generally based on the [[belief]] that [[relationships]] between heavenly bodies [[influence]] or convey [[information]] about [[events]] on [[Earth]]. The [[scientific]] study of the night sky and bodies observed within it, meanwhile, takes place in the [[science]] of astronomy.
The visibility of celestial objects in the night sky is affected by [http://en.wikipedia.org/wiki/Light_pollution light pollution]. The [[presence]] of the [[Moon]] in the night sky has historically hindered astronomical [[observation]] by increasing the amount of ambient lighting. With the advent of [[artificial]] light sources, however, light pollution has been a growing [[problem]] for viewing the night sky. Special filters and modifications to light fixtures can help to alleviate this problem, but for the best seeing both [[professional]] and [[amateur]] optical astronomers seek viewing sites located far from major urban areas.
On [[clear]] [[dark]] nights in unpolluted areas, when the [[moon]] is thin or below the [[horizon]], a band of what looks like white dust, the Milky Way, can be seen.
Shortly after sunset and before sunrise, [[artificial]] [[satellites]] often look like [[stars]] - similar in brightness and size, but different because they move relatively quickly; those that fly in near-earth orbit cross the sky in a couple of minutes. Some [[satellites]] (including [http://en.wikipedia.org/wiki/Space_junk space junk]) appear to blink or have a periodic fluctuation in brightness because they are [[rotating]].
[[Meteors]] (commonly known as shooting stars) streak across the [[sky]] very infrequently. During a meteor shower, they may [[average]] one a minute not at regular intervals, but otherwise their [[appearance]] is a [[random]] [[surprise]]. The occasional meteor will make a bright, fleeting streak across the [[sky]], and they can be very bright in comparison to the night sky.[http://en.wikipedia.org/wiki/Night_sky]
[[Category: Astronomy]]
