Squishy Moon

If you're ever out in space, try to watch the setting moon. Earth's atmosphere acts as a lens, squishing the moon as it disappears behind the horizon.

At first the lower limb is distorted most as the atmospheric lens pushes the lower limb upwards to create an egg shape (close-up). Finally the whole moon becomes an impossibly flattened oval. In the final frame the moon's lower edge is slightly clipped by the earth's surface. The lower part of the disk and then the entire moon is appreciably reddened by preferential atmospheric scattering of blue light out of the ray path.