I’ll be attending a µSymposium before the Lunar and Planetary Science Conference this coming weekend, and I just got a reminder e-mail today. Included in that e-mail was a link to an animation that shows Shackleton crater, a crater that is ON the moon’s north pole. As such, its interior is in permanent shadow.
BUT!! The Lunar Orbiter Laser Altimeter instrument (LOLA) on the Lunar Reconnaissance Orbiter (LRO) has plenty of data that allow it to be viewed: Click Me!.
I find this very neat — until the last decade, we could never see stuff in permanent shadow because we didn’t have the instrumentation. LOLA and LROC have allowed us to do that. And there are thousands of craters in permanent shadow on the moon that may hide water (which is what I’ll be presenting at the µSymposium).
For reference, the north pole of the moon is just about smack dab at the 10:30 position on the large crater’s rim. Just inside the rim, along a line from that small crater just outside the rim to the center of the crater.
But for pseudoscience, you may also notice that there are some artifacts in the data. There are radial streaks from the center of the frame (usually). There’s a prominent one diagonally from upper right to lower left on the upper wall of Shackleton itself. Others are more prominent towards the edges of the animation.
These are not lunar roads nor subways nor trollies nor anything else made by an ancient civilization. They are artifacts in the data itself. LOLA is very well calibrated, and the “average” (root-mean-square) uncertainty is under 5 meters in elevation data. But some tracks (orbits) are a bit off. And since LOLA is fundamentally measuring the time it takes light to bounce off the surface from a laser beam from the craft, it needs to know exactly where the craft was to get an accurate surface elevation.
And some are off by a bit. These manifest in this kind of product as ridges or troughs that are perfectly in a straight line, along the line of the orbital track. It’s something that scientists who use these data see and ignore because we know exactly what they are. But pseudoscientists will look at line artifacts like this, or at image seems in a mosaic, and claim things like they are artificial tram lines.