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"
Ring of Fire Revisited
30/05/2003
rly on Saturday, May 31 (UT) the new Moon will once again slide across the Sun's fiery disk, and once again an annular solar eclipse will be the result -- since the Moon's apparent diameter will be a little too small to completely cover the Sun. But this time celestial geometry has conspired to produce a broad D-shaped region for viewing the annular phase that extends into the far northern hemisphere, rather than creating a thin track racing across land and sea. The characteristic ring of fire will be visible from northern Scotland, Iceland, and parts of Greenland. Otherwise a partial eclipse will be more widely visible as across Europe, along with parts of Asia and North America, the Moon will appear to take a "bite" out of the Sun. While the northerly observers might certainly expect a dramatic view, it will probably not look quite like this one, recorded with a foreground of palm trees during a 1992 annular eclipse. Want to watch Saturday's eclipse on the web? Check out the planned webcasts from Astronet.