Earth seen from the moon on Feb. 1, 2014 by NASA’s Lunar Reconnaissance Orbiter.NASA/GSFC/Arizona State University
It’s a 21st-century version of the famous “Earthrise” photo taken by Apollo 8 astronaut Bill Anders in 1968: our brilliant blue world rising above the craters of the moon captured by NASA’s Lunar Reconnaissance Orbiter on Feb. 1, 2014.
The orbiter only occasionally has its camera — the LROC — pointed away from the moon in order to calibrate its position and obtain views of the lunar limb. During these rare events, Earth can pass through the field of view of the wide-angle camera (WAC), allowing for dramatic views like the one seen here.
Assembled from a combination of images acquired in various wavelengths of light, the result is a near true-color picture as it would appear to our eyes — including the relative brightness and vivid hues of the Earth, 217,000 miles (349,000 km) away. (The moon was at perigee the day before the images were taken.)
LROC’s camera doesn’t “snap” color pictures like your digital camera or cell phone does. Instead it uses a “push-frame” method of building up large images as it travels in its polar mapping orbit. The animation shown here gives an idea of how the WAC images the Moon, and also shows some of the different filters that were used to make up the color image above.
Animation of LROC WAC image filters, increased in speed by 20x.
Keep in mind that Earth doesn’t actually “rise” as seen from the moon. As the moon keeps the same face pointed toward us as it orbits, the Earth would always remain in pretty much the same place in the sky as seen from any one location on the Moon. The rising effect in the animation is due entirely to LRO’s orbit.
Source and credit: NASA/Goddard/Arizona State University