The surface

Craters, seas and dust

Grey rock, dark lava plains, bright craters and ice in places the Sun never reaches. No wind has ever tidied any of it up.

Craters everywhere

The Moon is covered in craters from asteroids, meteoroids and comets. There’s too little air to slow them down. NASA Science: Moon facts With no wind or air to wear them away, the Moon’s craters stay for a very long time. NASA Space Place: All about the Moon

A large round crater with a central peak and bright rays of material around it — Tycho Crater, in a mosaic of pictures from NASA’s Lunar Reconnaissance Orbiter.Photo: NASA/GSFC/Arizona State University, Public domain, Commons

Tycho Crater is more than 85 km wide. NASA Science: Moon facts

A big crater with terraced walls and a cluster of peaks in the middle — Copernicus Crater, seen by NASA’s Lunar Reconnaissance Orbiter.Photo: NASA (image by Lunar Reconnaissance Orbiter), Public domain, Commons

The dark ‘seas’

The dark patches are called maria, Latin for ‘seas’. They’re huge basins that filled with lava between 4.2 and 1.2 billion years ago. NASA Science: Moon facts The light areas are called the highlands. NASA Science: Moon facts

The Moon’s ‘seas’ aren’t water. They’re old lava. NASA Space Place: All about the Moon

Dust and rubble

Nearly the whole Moon is covered in charcoal-grey powdery dust and rocky rubble called regolith. NASA Science: Moon facts The finest Moon dust is smaller than 10 to 20 microns, much thinner than a human hair. NASA Science: What the Moon is made of

On the old highlands, the regolith can be 20 metres deep. NASA Science: What the Moon is made of

A sharp bootprint pressed into fine grey lunar dust — A bootprint in the lunar dust, photographed by Buzz Aldrin on Apollo 11.Photo: NASA / Buzz Aldrin, Public domain, Commons

How bright is it really?

Only about a tenth of the sunlight that hits the Moon bounces back. From Earth it looks bright, almost white, but much of its surface is really shades of dark grey. NASA Science: Moonlight

Water and ice

The first definitive discovery of water on the Moon was made in 2008 by India’s Chandrayaan-1 mission. NASA Science: Moon facts There is water ice in permanently shadowed craters at the Moon’s poles, where sunlight never reaches. NASA Science: Moon facts

In 2009 NASA’s LCROSS spacecraft fired a projectile into a crater, then flew through the debris and found grains of water ice in it. NASA Science: Water and ices on the Moon

In October 2020 NASA’s SOFIA observatory confirmed water on the sunlit surface of the Moon for the first time, in Clavius Crater. NASA Science: Moon facts

Things left behind

Astronauts left things behind on the Moon: equipment, American flags and even a camera. NASA Science: Moon facts

Grey, cratered ground seen from above, with labels pointing to the lunar module, a camera and experiments left behind — The Apollo 11 landing site seen from orbit by NASA’s Lunar Reconnaissance Orbiter.Photo: NASA/GSFC/Arizona State University, Public domain, Commons

LRO has photographed the Apollo 11 landing site: the descent stage left behind is visible, and so are the trails of the astronauts’ footprints. NASA Science: Apollo 11 landing site, seen by LRO

Is anything alive?

Missions to the Moon have found no evidence that it has living things of its own. NASA Science: Moon facts

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