Related topics: nasa

Plants get a faster start to their day than we think

To describe something as slow and boring we say it's "like watching grass grow", but scientists studying the early morning activity of plants have found they make a rapid start to their day—within minutes of dawn.

Image: Ahuna Mons on Ceres

This image, based on observations from NASA's Dawn spacecraft, shows the largest mountain on the dwarf planet Ceres.

ESA's Hera asteroid mission borrows eyes of NASA's Dawn

The mission to the smallest asteroid ever explored will employ the same main camera as the mission to the largest asteroids of all. ESA's proposed Hera spacecraft to the Didymos asteroid pair has inherited its main imager ...

Dawn mission to asteroid belt comes to end

NASA's Dawn spacecraft has gone silent, ending a historic mission that studied time capsules from the solar system's earliest chapter.

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Dawn

Dawn is the time that marks the beginning of the twilight before sunrise. It is recognized by the presence of weak sunlight, while the sun itself is still below the horizon. Dawn should not be confused with sunrise, which is the moment when the leading edge of the sun itself appears above the horizon.

The duration of the twilight period between dawn and sunrise varies greatly depending on the observer's latitude, from a few minutes in equatorial regions to many hours in polar regions. Dawn may easily be determined by observing a thread. When the color of a thread can be determined, changing from black to the thread's distinctive color, the 'crack of dawn' has occurred. This same measure of ambient light can be used to determine, conversely, the instant of dusk.

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