Zooming close to the earth or other planets with relief (Mars), or through a valley with mountains on either side, and bringing the camera angle to low incidence causes the ground to disappear / or polygons to disappear in mountainsides "allowing" you to see through the planet.
Zooming close to the earth or other planets with relief (Mars), or through a valley with mountains on either side, and bringing the camera angle to low incidence causes the ground to disappear / or polygons to disappear in mountainsides "allowing" you to see through the planet.
(per Christina Moraitis)