Astronautics

Astronautics - (alternatively cosmonautics) is the theory and practice of navigation beyond Earth's atmosphere. http://en.wikipedia.org/wiki/Astronautics

Total Eclipse

Umbra - The umbra (Latin for "shadow") is the innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body
Penumbra - The penumbra (from the Latin paene "almost, nearly" and umbra "shadow") is the region in which only a portion of the light source is obscured by the occluding body.

Source: http://en.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra

Geminid Meteor Shower (Sky & Telescope)

Source: Sky & Telescope

Why does the moon change shape? (Youtube)

Barringer Crater in Arizon

diamteter: 1,200 meters
depth: 150 meters

For more information, click here