The Moon
The Moon is Earth’s only natural satellite—a rocky, cratered body about one‑quarter the diameter of Earth, orbiting at an average distance of approximately 384,400 km. It influences tides, stabilizes Earth’s axial tilt, and was formed about 4.5 billion years ago following a collision between Earth and a Mars-sized object.
Source: science.nasa.gov
APODs including "The Moon"
X-Raying the Moon
31/08/1995
August 31, 1995 X-Raying the Moon Credit: DARA, ESA, NASA, Max Planck Institut, J.H.M.M. Schmitt Explanation: Above is a picture of the Moon taken in X-rays by the Roentgen Observatory Satellite ROSAT in 1990. This famous picture shows three distinct regions: a bright X-ray sky, a bright part of the Moon, and a relatively dark part of the Moon. The bright X-ray region is exemplary of the mysterious X-ray background that is seen everywhere on the sky. The bright lunar crescent shines because it reflects X-rays emitted by the Sun. The dark lunar face is surprising because it is not completely dark, and its slight emission is thought to result from energetic particles from the solar wind striking the Moon.