Most of us see the moon almost every night, but few people have seen a decent high-res picture of the moon, let alone a high-res picture of the dark side of the moon. To be able to see the moon - every side of it - in detail would really require being in space and flying around it. And 99.9% of us Earthlings don't have that opportunity (yet). So once again, NASA has come to the rescue, this time providing us with an amazing 3D map of the whole moon for computer graphics artists to use to their heart's content. For the first time, we can explore the moon (digitally). And it's incredible. If you want to see some more amazing photos from NASA, check out these new photos of Mars.
As we all know, there's a far side of the moon that Earth never sees. It has been glimpsed by astronauts and satellites a few times, but the resulting photos haven't been as high res as we would hope in our age of incredible technology. For something we see almost every night, our one and only moon, you would hope that we could at least see it in detail.
But there are a few obstacles, including the fact that the moon moves at around a mile per second with a light source that's 93 million miles away, and to accurately map it topographically it must be exact within 100 feet.
This is where NASA comes in.
NASA's Lunar Reconnaissance Orbiter (LRO) was built with these problems in mind, and had been orbiting the moon for a decade, taking photos and measurements the whole time. The LRO has a sophisticated multispectral imager on board, which can take an extremely high resolution photo of a small portion of the moon at a time. Since the LRO has been orbiting for 10 years, it's managed to cover the entire surface of the moon, including the side that inspired Pink Floyd (the dark side).
But the map isn't only 2D - while images were being taken of the moon's surface, a laser altimeter has been measuring the topography of the moon. This works by sending a pulsed laser towards the surface of the moon and tracking how long it takes to come back and how strong it is. From this, the laser altimeter can tell how far away the surface is, it's altitude, and the structure of the surface (rocky or soft, for example).
The data gathered by the laser altimeter is used to create a displacement map, which is like a topographic map but instead of the height changing, the color does. Once you overlay this with the photographic map of many high-resolution photos of the moon's surface sewn together, and wrap this around a sphere, it created a virtual topographic globe. And that's exactly what NASA has done.
This map is available to download for free, so we're guessing that CG artists are going to have a field day with this amazing new technology. It might even be able to help experts plan future lunar colonies. However it will be used, it's pretty great that we can explore the moon from the comfort of our lounge rooms. Where there's plenty of oxygen and gravity to go around.