The genetic secret of night vision

One of the most remarkable characteristics of the vertebrate eye is its retina. Surprisingly, the sensitive portions of the photoreceptor cells are found on the hind side of the retina, meaning that light needs to travel ...

Image: Hubble views galaxy from famous catalog

This bright, somewhat blob-like object—seen in this image taken by the NASA/ESA Hubble Space Telescope—is a galaxy named NGC 1803. It is about 200 million light-years away, in the southern constellation of Pictor (the ...

New device in New Mexico turns back clock on astronomy

A newly forged steel instrument that can pinpoint the path of stars and planets across the night sky using the naked eye is a throwback to the years just before the advent of telescopes, returning stargazers in the hills ...

Change of shifts at the north pole

After exchanging research teams and crewmembers, the greatest expedition to the Central Arctic of all time is now entering the next phase, during which urgently needed research into the Arctic climate system will be conducted. ...

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Night

Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day (or "daytime" to distinguish it from "day" as used for a 24-hour period). The start and end times of night vary based on factors such as season, latitude, longitude and timezone.

At any given time, one side of the planet Earth is bathed in light from the Sun (the daytime) and the other side of the Earth is in the shadow caused by the Earth blocking the light of the sun. This shadow is what we call the darkness of night.

This text uses material from Wikipedia, licensed under CC BY-SA