A NASA satellite a million miles from Earth has captured a dramatic image of the dark side of the moon as our cosmic companion passed in front of our planetary home.
A series of images of the fully sun-illuminated "dark side," never visible from the Earth's surface, were taken by the space agency's Deep Space Climate Observatory (Dscovr) satellite.
Taken over a five-hour period on July 16 by the satellite's Earth Polychromatic Imaging Camera (EPIC), a 4 megapixel camera and telescope instrument, the images show the moon slowly moving over the Pacific Ocean near North America.
The satellite's primary mission is to conduct real-time monitoring of the solar wind for the National Oceanic and Atmospheric Administration.
The dramatic images of the moon and the Earth were a bonus, NASA scientists say, and show a dramatic contrast between the two.
"It is surprising how much brighter Earth is than the moon," says 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."
Launched in February, the Dscovr satellite arrived in its distant orbit several weeks ago, training its EPIC camera/telescope on Earth.
As the moon passed between the satellite and the Earth, the instrument began snapping images about every 30 seconds, providing a good look at the side of the moon we never see from Earth.
Although the moon orbits our planet, it never presents its "dark side" to our view because it is tidally locked to our world, always presenting the same face to us.
The "dark side" isn't really dark, of course; as it travels in its orbit, all sides of the moon receive sunlight — as seen in the newest images — but since humans have never seen the far side from Earth, it's been considered unknowable, thus "dark."
The far side is distinct in character, NASA points out, lacking the extensive dark, basaltic plains known as maria or lunar "seas" so visible on the side of the moon facing the Earth.
It has one, Mare Moscoviense, visible in the upper left of the Dscovr images.
After a period of testing and adjustments, the satellite will begin a regular mission of observations in September, and NASA says it will post daily color images of the Earth to a dedicated website the public can browse.
As our planet rotates through its days, images will be snapped and will be on the website between 12 and 36 hours after they are acquired, the space agency announced.
