The Lunar Reconnaissance Orbiter really outdid itself with this amazing shot of the Earth over the rocky limb of the Moon. While complicated to capture, we think it was worth every moment.
This gorgeous image of the Earth was taken on October 12, 2015 as the LRO spacecraft soared nearly 22 miles over the edge of Compton crater on the Moon. The image centres on Africa, with a hint of South America creeping around the horizon.
The Moon has no daily Earthrise and Earthset. Because it is tidally locked to the Earth, the planet always appears at the same spot above the horizon, minus a tiny wobble. This is where the Earth appears relative to Compton crater every day, with only the oceans and continents rotating to provide an ever-changing view.
Black and white image with natural contrast [left], then the Moon contrast stretched [middle] and the Earth colorised [right]. Image credit: NASA/GSFC/Arizona State University
Taking this photo with the Lunar Reconnaissance Orbiter wasn’t easy. First, the camera needed to roll on its side, then it slewed over to maximise how much of the lunar horizon it could see. The Narrow Angle Camera is a line scanner, capturing a geometrically distorted raw image that needed to be stitched together. Goddard Space Flight Center put together this animation to illustrate how they manoeuvred the spacecraft during the image capture sequence:
Once the black-and-white image was assembled, it only took a bit of tinkering to finalise this real photo of home. First, the contrast was stretched to brighten up our dark, dark Moon into something more visible. Then, colour data from the Wide Angle Camera was added to match what out home looked like at that exact moment in rich blues and dusty browns, although in a narrower spectrum than we’d see with our more sensitive human eyes.
That’s a lot of effort for one photo, but the results are simply lovely. Thank you, NASA. [NASA]
Top image: Earth from above Compton crater on the Moon. Credit: NASA/GSFC/Arizona State University