Today NASA released an amazing image of Earth taken from the Moon — specifically from lunar orbit by NASA’s Lunar Reconnaissance Orbiter, which has been studying our Moon since the summer of 2009. In it our planet appears as an incredibly bright blue globe with swashes of white clouds and Africa and northeastern South America clearly visible beyond the rolling grey hills of the Moon. It’s so clear and perfect it almost doesn’t look real — so is it?
Why yes. Yes it is. (But of course there was a little help needed from the LROC imaging teams at Arizona State University and Goddard Space Flight Center!)
The Lunar Reconnaissance Orbiter Camera (LROC) isn’t like the camera on your cell phone or a digital or film camera you might use for hobby photography. (I’m a Nikon fan myself.) It doesn’t just “snap” a color photo of whatever it’s pointed at; instead, it captures monochrome (i.e., black-and-white) image data in specific narrow-band wavelengths that are used for scientific studies of the lunar surface but can later be combined to create approximate true-color images of the Moon (and, in this case, Earth.)
And since the Moon is generally much darker in color than Earth — and thus reflects less of the Sun’s light — the contrast was adjusted to compensate. (You can get an idea of what I mean below.)
Also the whole way that LROC’s narrow-angle camera obtains image data is not like a point-and-shoot camera; it’s a line scanner that takes “sweeps” as the spacecraft is in motion, which makes it necessary to adjust for distortion. And the color data came from the wide-angle camera — a different instrument entirely.
So is the image real? Yes. Was it “manipulated?” Yes. But basically so are all photographic images, since they all require machinery or a device of some sort to create an image that your eyes and brain can experience. Cameras aren’t brains, and eyes aren’t cameras — some amount of handiwork is always needed (sometimes more than others!) But the view was there, and thanks to the LROC team we get to see it.
By the way if you really want to knock your socks off, check out a super-high resolution color version here (big file).
The very first image of Earth from the Moon was captured in August 1966 by NASA’s Lunar Orbiter I, and then more famously on Dec. 24, 1968 by the crew of Apollo 8. Of course, being tidally locked, from any one spot on the Moon the Earth doesn’t ever “rise” — it always remains in more or less the same location (where it’s visible at all.) But it does appear to rotate, and will also go through phases like the Moon does from Earth. A “rising” effect is only witnessed from spacecraft in lunar orbit.