News tagged with dawn
Dawn Spacecraft Fires Past Record for Speed Change (w/ Video)
(PhysOrg.com) -- Deep in the heart of the asteroid belt, on its way to the first of the belt's two most massive inhabitants, NASA's ion-propelled Dawn spacecraft has eclipsed the record for velocity change ...
Space & Earth / Space Exploration
Jun 08, 2010 |
4.9 / 5 (21) |
11
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NASA's new ion engine ready for missions in space
(PhysOrg.com) -- A small robotic surveyor arrives to explore a near-Earth asteroid. Another robotic spacecraft is returning to Earth with a pristine comet surface sample. Meanwhile, a robotic explorer is approaching ...
Space & Earth / Space Exploration
Apr 15, 2011 |
4.8 / 5 (17) |
8
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Glorious Dawn: Sagan, Hawking Sing (w/ Video)
Astronomer and long time science advocate Carl Sagan once said that he was "not very good at singing songs." But on Nov. 9 in Washington D.C., his voice could be heard singing about the wonders of universe -- 13 years after ...
Nov 12, 2009 |
4.6 / 5 (17) |
8
Cosmologists 'see' the cosmic dawn
(PhysOrg.com) -- The images, produced by scientists at Durham University's Institute for Computational Cosmology, show the "Cosmic Dawn" - the formation of the first big galaxies in the Universe.
Feb 11, 2009 |
3.4 / 5 (21) |
18
Is Vesta the 'smallest terrestrial planet?'
NASA's Dawn spacecraft spent the last four years voyaging to asteroid Vesta – and may have found a planet.
Space & Earth / Space Exploration
Dec 12, 2011 |
4.5 / 5 (13) |
9
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Countdown to Vesta
Let the countdown begin. NASA's Dawn spacecraft is less than one year away from giant asteroid Vesta.
Space & Earth / Space Exploration
Aug 20, 2010 |
4.8 / 5 (12) |
5
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Dawn probe reaches milestone approaching asteroid Vesta
(PhysOrg.com) -- NASA's Dawn spacecraft has reached its official approach phase to the asteroid Vesta and will begin using cameras for the first time to aid navigation for an expected July 16 orbital encounter. ...
Space & Earth / Space Exploration
May 03, 2011 |
5 / 5 (11) |
3
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Dawn spacecraft approaches protoplanet Vesta
(PhysOrg.com) -- NASA's Dawn mission to the doughnut-shaped asteroid belt between Mars and Jupiter, which launched in September 2007, is now approaching Vesta, a protoplanet that is currently some 143 ...
Space & Earth / Space Exploration
Jun 10, 2011 |
5 / 5 (11) |
2
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Space mountain produces terrestrial meteorites
When NASA's Dawn spacecraft entered orbit around giant asteroid Vesta in July, scientists fully expected the probe to reveal some surprising sights. But no one expected a 13-mile high mountain, two and a half ...
Space & Earth / Space Exploration
Jan 02, 2012 |
4.2 / 5 (13) |
7
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NASA Spacecraft Falling For Mars
(PhysOrg.com) -- Launched in September of 2007, and propelled by any one of a trio of hyper-efficient ion engines, NASA's Dawn spacecraft passed the orbit of Mars last summer. At that time, the asteroid belt ...
Space & Earth / Space Exploration
Feb 13, 2009 |
4.3 / 5 (12) |
2
NASA's Dawn Spacecraft Enters Orbit Around Asteroid Vesta
NASA's Dawn spacecraft on Saturday became the first probe ever to enter orbit around an object in the main asteroid belt between Mars and Jupiter.
Space & Earth / Space Exploration
Jul 17, 2011 |
5 / 5 (10) |
11
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NASA's Dawn spacecraft beams back new photo
(PhysOrg.com) -- Dawn took this image during its current orbit of Vesta, traveling from the day side to the night side.
Space & Earth / Space Exploration
Jul 22, 2011 |
5 / 5 (10) |
8
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When is an asteroid not an asteroid?
(PhysOrg.com) -- On March 29, 1807, German astronomer Heinrich Wilhelm Olbers spotted Vesta as a pinprick of light in the sky. Two hundred and four years later, as NASA's Dawn spacecraft prepares to begin ...
Space & Earth / Space Exploration
Mar 30, 2011 |
4.8 / 5 (10) |
4
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Dawn beams back asteroid science data
(PhysOrg.com) -- The Dawn spacecraft has completed a graceful spiral into the first of four planned science orbits during the spacecraft's yearlong visit to Vesta. The spacecraft started taking detailed observations ...
Space & Earth / Space Exploration
Aug 12, 2011 |
5 / 5 (9) |
5
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New NASA dawn visuals show Vesta's 'color palette'
(PhysOrg.com) -- Vesta appears in a splendid rainbow-colored palette in new images obtained by NASA's Dawn spacecraft. The colors, assigned by scientists to show different rock or mineral types, reveal Vesta ...
Space & Earth / Space Exploration
Dec 06, 2011 |
5 / 5 (9) |
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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.
For more information about Dawn, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
