This animation features actual satellite images of
the far side of the moon, illuminated by the sun, as it crosses between
the DSCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) and
telescope, and the Earth - one million miles away.
Credits: NASA/NOAA
 |
| Pela 2ª vez na história, a Lua passou entre a Terra e o satélite DSCOVR, que observa o planeta e o clima espacial. Desta forma, pudemos enxergar o 'lado de trás' da Lua, iluminado pelo Sol. |
These images were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the moon moving over the Pacific Ocean near North America. The North Pole is in the upper left corner of the image, reflecting the orbital tilt of Earth from the vantage point of the spacecraft.
This image shows the far side of the moon,
illuminated by the sun, as it crosses between the DSCOVR spacecraft's
Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the
Earth - one million miles away.
Credits: NASA/NOAA
The far side of the moon was not seen until 1959 when the Soviet Luna
3 spacecraft returned the first images. Since then, several NASA
missions have imaged the lunar far side in great detail. The same side
of the moon always faces an earthbound observer because the moon is
tidally locked to Earth. That means its orbital period is the same as
its rotation around its axis.
In May 2008 NASA’s Deep Impact spacecraft captured a similar view of
Earth and the moon from a distance of 31 million miles away. The series
of images showed the moon passing in front of our home planet when it
was only partially illuminated by the sun.
EPIC’s “natural color” images of Earth are generated by combining
three separate monochrome exposures taken by the camera in quick
succession. EPIC takes a series of 10 images using different narrowband
spectral filters -- from ultraviolet to near infrared -- to produce a
variety of science products. The red, green and blue channel images are
used in these color images.
Combining three images taken about 30 seconds apart as the moon moves
produces a slight but noticeable camera artifact on the right side of
the moon. Because the moon has moved in relation to the Earth between
the time the first (red) and last (green) exposures were made, a thin
green offset appears on the right side of the moon when the three
exposures are combined. This natural lunar movement also produces a
slight red and blue offset on the left side of the moon in these
unaltered images.
The lunar far side lacks the large, dark, basaltic plains, or maria,
that are so prominent on the Earth-facing side. The largest far side
features are Mare Moscoviense in the upper left and Tsiolkovskiy crater
in the lower left. A thin sliver of shadowed area of moon is visible on
its right side.
“It is surprising how much brighter Earth is than the moon," said
Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight
Center in Greenbelt, Maryland. "Our planet is a truly brilliant object
in dark space compared to the lunar surface.”
Once EPIC begins regular observations next month, NASA will post
daily color images of Earth to a dedicated public website. These images,
showing different views of the planet as it rotates through the day,
will be available 12 to 36 hours after they are acquired.
DSCOVR is a partnership between NASA, NOAA and the U.S. Air Force
with the primary objective of maintaining the nation’s real-time solar
wind monitoring capabilities, which are critical to the accuracy and
lead time of space weather alerts and forecasts from NOAA.
For more information about DSCOVR, visit:
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