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"
Partial Eclipse, Cloudy Day
21/12/2001
Welcome to the December Solstice, first day of winter in the north and summer in the southern hemisphere of planet Earth. Today the Sun reaches its southernmost declination in the sky at 19:21 Universal Time. Just a short week ago, as the Sun approached the end of its annual journey south, it was eclipsed by the Moon. Observers in Costa Rica witnessed a fleeting annular eclipse with the Moon surrounded by a dramatic bright ring as it covered about 96 percent of the visible solar surface during the maximum phase. But from most of the Americas this eclipse was partial ... and skies were often partially cloudy! Public Television Engineer Stan Richard captured this view near Des Moines, Iowa, USA. Taken close to eclipse maximum for his location, the sharp, silhouetted edge of the Moon is visible through the clouds in the lower left quadrant of the solar disk.