The Moon partially obscured the view of the Sun from the Solar Dynamics Observatory last Saturday. This lunar transit was visible only from SDO’s point of view in space. SDO imagery during a lunar transit always shows a crisp horizon on the Moon. That edge is well defined because the moon has no atmosphere around it to distort the sunlight. The horizon is so clear in these images that the irregularity resulting from mountains and valleys in the terrain can be seen. Click the image to embiggen it, and pan across the Moon’s horizon. It’s a 4k x 4k image, so you may have to click it twice to see it full size.

Image Credit: NASA