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
19/04/2002

Also known as the Moon's "ashen glow" or "the old Moon in the new Moon's arms", Earthshine is Earthlight reflected from the Moon's night side. This dramatic image of Earthshine and a young crescent Moon was taken by astrophotographer and APOD translator Laurent Laveder from the remote Pic du Midi Observatory on planet Earth. But the view from the Moon would have been stunning too. When the Moon appears in Earth's sky as a slender crescent, a dazzlingly bright, nearly full Earth would be seen from the lunar surface. The Earth's brightness, due to reflected sunlight, is strongly influenced by cloud cover and recent studies of Earthshine indicate that it is more pronounced during April and May. A description of Earthshine, in terms of sunlight reflected by Earth's oceans in turn illuminating the Moon's dark surface, was written 500 years ago by Leonardo da Vinci.