When viewing the moon it usually appears colourless, but by adjusting the colour saturation in processing, it is possible to bring out the colour details which our eyes are otherwise not sensitive enough to see. Click on the 'Mineral View' button to display James Clark's tremendous mineral image.
Move your mouse over the Moon, to identify the main features & click to display further information.
The Moon is thought to have formed about 4.5 billion years ago. Extensive meteoric bombardment created large basins, hundreds of kilometers across, and resulted in the melting and chemical separation of the surface. About 4 billion years ago the bombardment eased & the residual heat (together with heat from radioactive elements) resulted in melting of the surface down to depth of 200km.
Lava from the resulting volcanic activity then rose and filled the basins, with basalt rock forming in the dark flat-ish areas called maria (or 'seas'). Subsequently, over the last 3 billion years, the lunar surface has only been altered by crater impacts & the occasional Earth space mission.
Over the last 3 billion years the large meteor impacts have helped spread & mix material around on the surface, and together with the large number of small meteorites, have created a lunar soil called 'regolith'. This is a mixture of powdered rock and rubble which varies from 1 to 20m deep.
The Moon's highland features age between 3.8 to 4.48 billion years. The maria rocks, aged 3.1 to 3.8 billion years, have more titanium, magnesium and iron, giving them either a blue-ish or rusty appearance. These are the youngest rocks on the Moon but were formed at around the same time as the oldest surviving rocks on Earth.
Tycho is one of the moons most prominent impact craters, with it's bright rays of ejected material reaching as far as 1,500km from the impact site. The ejecta is most apparent around full moon, as in this webpage's main image by James Clark. The above picture, taken at a few days earlier in the lunar cycle, shows Tycho towards the middle right, with the distinctive Clavius crater near the bottom centre.
Tycho itself has a diameter of 85km and a depth of 4,800m. It is estimated to be about 108 million years old.
The crater is named after the great Danish astronomer Tycho Brahe.
Like Tycho, Copernicus is one of the moons most prominent craters. Near full moon, it appears surrounded by a large irregular area of bright streaks of ejecta, extending up to 800km.
Located to the south of Montes Carpatus and Montes Apenninus, it's circular rim has a hexagonal shape with a terraced inner wall and a 30km wide sloping rampart that decends nearly 1km in height down to the Mare floor.
About 93km wide and formed roughly 800 million years ago, Copernicus was formed by an object similar in size (a few km across) to the one responsible for the K-T extinction impact on Earth which wiped out the dinosaurs. The central peaks in the crater are about 1.2km above the crater floor, and consist of Olivine rock.
This crater is named after the great astronomer Nicholaus Copernicus, who came up with the idea that the Sun was at the centre of the solar system, rather than the Earth.
Kepler is located near the much larger Copernicus crater, although near full moon it's ejecta rays can be seen radiating an impressive 300km from the impact site.
The crater is about 32km wide and is named after the noted German astronomer Johannes Kepler, who derived the three laws of planetary motion.
Manilius, seen here in the middle of Kevin Taylor's image, has a diameter of about 38km. It has a well-defined rim with a strongly sloping inner surface that runs directly down to the ring-shaped mound of scree along the base, and a small outer rampart. The small crater interior has a higher albedo (reflectivity) than the surroundings, making it appear bright near full moon. Within the crater is a central peak formation near the midpoint.
The crater also possesses a ray system that extends for a distance of over 300km.
Manilius is named after the Roman astronomer Marcus Manilius.
Posidonius is a lunar impact crater which has partially filled with a lava flow. Inside the crater the faint remains of a second smaller crater can be seen with a semi-circular rim appearing above the lava bed. Higher resolution images also show a rille system of collapsed lava tubes. Posidonius's crater ramparts can also still be seen, mainly to the south and east of the rim.
Posidonius is named after the Greek philosopher and geographer Posidonius of Apamea.
The Eudoxus crater appears to be quite prominent around full moon. Unlike some of the other main craters this one doesn't have a prominent central peak, instead having a cluster of low hills near the centre. The rim of Eudoxus has a series of terraces on the inside of the interior wall and alightly worm ramparts around the exterior.
In this image the larger Aristoles crater lies to the north, with the Montes Caucasus mountain range on the left hand side below. The crater on the left hand side with a smaller crater inside is Cassini.
Eudoxus is named after the ancient Greek astronomer Eudoxus of Cnidus.
The Eratosthenes crater, seen here on the left of the image, has a diameter of approximately 59km. It's believed to have been formed about 3.2 billion years ago by the impact of an asteroid. The impact would have had enough energy to melt the local area of rock, which then formed the central peak & raised edges.
The crater is named after the ancient Greek mathematician & astronomer, Eratosthenes, who estimated the circumference of the Earth and the distance from the Earth to the Sun in the 3rd century BC.
The Aristoleles impact crater lies to the north of Eudoxus & is the larger of the two. The craters are linked on the west side by an arc of mountains, and a smaller crater, Mitchell, can be seen adjacent to Aristoleles rim.
The crater wall of Aristotle has a slightly distorted rounded hexagonal shape, with wide inner walls. The outer ramparts show some hillocks and extensive ejecta. The inner part of the crater also appears to have been partiall filled with a layer of material.
Aristoleles is named after the ancient Greek philosopher Aristotle.
Hercules crater is located 30km to the west of Atlas, and is somewhere between 1.1 and 3.2 billion years old. It's interior walls show multiple terraces, with a small outer rampart. The small impact crater in the floor is the 13km wide Hercules G.
Hercules is named after a roman version of the mythical Greek divine hero Heracles.
Atlas crater is located 30km to the east of Hercules. It has a diameter of 88km and it's about 2km deep. Atlas was formed somewhere between 3.2 - 3.8 billion years ago. It's fractured floor is thought to be due to volcanism.
Near full moon two dark patches become apparent in the crater, called Atlas North and Atlas South.
85km to the east of Atlas is a small 2.5km ray crater which is visible as a bright spot. This is a relatively new crater with bright well defined rays.
The crater is named after the ancient Greek god, Atlas.
Endymion crater, which is 126km wide and 4km deep, lies to the north of Hercules & Atlas, and is estimated to be over 3.9 billion years old. Low albedo (reflectivity) lava has filled the floor of the crater giving it a smooth appearance & it appears as a dark patch when viewed near full moon.
The crater is named after the mythological Greek youth who spent much of his life in perpertual sleep. He was loved by Selene, the goddess of the moon, who visited him every night & bore him 50 daughters...
Grimaldi crater, which is situated near the moon's western limb, is approx 222km in diameter with an inner region of about 174 km. The crater has been filled by a lava flow and is the darkest crater on the moon. It is at least 3.9 billion years old.
The rock density beneath the surface of the crater is greater than average, with a mass concentration ('mascon') suficiently big enough to affect orbiting spacecraft.
The crater is named after Francesco Grimaldi, a pupil of the Italian astonomer Giovanni Riccioli, who named many of the moon's craters in his 1651 moon map. Riccioli's naming methodology was somewhat biased, and in a deliberate snub to Galileo Galilei only named a rather small crater after him, proclaiming that he had: flung Galileo into the Ocean of Storms.
Clavius is a LAS members' favourite crater, possibly owing to it being the site of the fictional 'Clavious lunar base' in the '2001 - A Space Odyssey' film. The crater is about 4 billion years old and has a diameter of 225km (about the distance between Leeds and Oxford).
The two smaller craters which can be seen intersecting Clavius' rim on the north and south edges are Porter (53km) and Rutherford (55km).
In October 2020, NASA confirmed the existence of molecular water near Clavius, at concentrations of up to 412 parts per million.
The crater is named after the Jesuit priest/mathematician/astronomer Christopher Clavius.
Plato is a lava filled crater which is about 109km wide and 3.8 billion years old.
Just below Plato in Mare Imbrium, Montes Recti, Montes Teneriffe & Mons Pico can be seen rising out of the lava filled floor.
Plato is named after the well known ancient Greek philosopher.
Aristarchus crater is arguably the brightest feature on the moons surface, with an albedo (reflectivity) almost double that of most lunar features. It appears bright because it is only about 450 million years old
The crater is named after the ancient Greek astronomer and mathematician Aristarchus of Samos, who presented the first helicentric model with the Sun at the centre of the known universe.
Montes Apenninus - the 'Apennine Mountains', is an impressive rugged mountain range on the edge of Mare Imbrium. It extends approx 600km in length and some of its peaks are over 5km high. The crater on the left of the image is Eratosthenes.
The mountain range is named after the Apennine Mountains in Italy.
Sinus Iridum - the 'Bay of Rainbows', is the name given to the plain of basaltic lava which has filled a large 236-250km diameter impact crater on the edge of Mare Imbrium.
The surviving section of the crater wall forms the Montes Jura mountain range on the 'coast' of the bay, with two raised mountainous capes at either end, Promontorium Heraclides (south) and Promontorium Laplace (north).
The bay is well known for it's 'clair-obscur' (French for 'light-shadow') effect, when the sunlight can be seen first seen reflecting off the mountain tops of the Montes Jura range, whilst the bay itself remains in shadow.
Although the age of the bay isn't known, Mare Imbrium is over 3 billion years old and the impact that formed Sinus Iridum occurred before the great lava floods took place.
The bay was named by the Italian astronomer Giovanni Riccioli on his 1651 map of the moon.
Sinus Medii is a rather featureless small lunare mare which gets it's name from its location at the intersection of the Moon's equator and prime meridian. From Earth Sinus Medii appears in the centre of the moon and is the point closest to Eath. From this point Earth would appear more or less directly overhead.
If Apollo 11's flight to the moon in 1969 had been delayed by a couple of days, Sinus Medii would have been the chosen landing site, instead of Mare Tranquillitas, as the flight operation planners were concerned about having optimum lighting conditions at the site.
Sinus Aestuum - the 'Seething Bay', is is a level, mostly featureless surface of low albedo basaltic lava with an area of irregular terrain to the east which separates the bay from the Mare Vaporum. To the north is the Montes Apenninus range and the prominent crater Eratosthenes, with Copernicus to the west.
Sinus Aestuum was one of the proposed sites for a large lunar base by the US Army in the late 1950s.
Mare Crisium - the 'Sea of Crises' has an elliptical shape with axis 450km / 556km, and a total area not exceeding that of Great Britain. It was formed 3.85 to 4.55 billion years ago.
The mare has been the target of some of the Soviet Luna missions, including Luna 24 which successfully returned a soil sample from the 'sea' in August 1976.
The largest crater visible in the lava bed is Picard (named after the 17th century French astronomer and geodesist Jean Pickard - not the Jean-Luc Pickard of Star Ship Enterprise!). On the western edge of Mare Crisium you can also see a bright young crater, Proclus, which was formed sometime in the last 1.1 billion years, and is 27km across & 5.5km deep.
Mare Serenitatas - the 'Sea of Serenity', is one of the moons main lava filled areas. It was formed 3.9 billion years ago and has a diameter of about 650-674km.
The Mare borders onto Mare Tranquillitatis, which has a much darker coloured basalt. The difference in the colours between the maria suggests that Mare Serentitias is the younger of the two.
The large filled crater on the top right of Mare Serenitatas is Posidonius.
Mare Tranquilitatis - the 'Sea of Tranquility', is the site of the first manned landing on the moon by Neil Armstrong & Buzz Aldrin in 1969 from Apollo 11.
The mare basin is thought to be between 3.9 - 4.5 billion years old, but the lava filled mare itself is somewhere between 3.2 - 3.85 billion years. Interestingly, although most mare's show regions of higher rock mass from their impact collisions ('mascons'), Mare Tranquilitatis doesn't have a mascon.
In photographs Mare Tranquilitatis has a distinct dark blue colour due to the relatively high proportion of titanium dioxide (over 7% by weight).
The area to the south of the mare, where Apollo II landed has been renamed 'Statio Tranquillitatis' (Tranquility Base).
Mare Fecunditatis - the 'Sea of Fecundity / Fertility' is a huge lava filled basin measuring approx. 600 × 500km. The basin itself is over 3.9 billion years old, whilst the basalt lava rock is between 3.2 and 3.8 billion years old. The mare also doesn't have a distinct higher mass concentration ('mascon') in the rock, and the depth of basalt is shallower than on the neighbouring Mare Tranquilitatis & Mare Crisium.
On the eastern edge, sits the Langrenus crater, and on the western edge several craters and the Montes Pyrenaeus separate the mare from Mare Nectaris.
Mare Fecunditatis is also the location where the first automated rock sample was collected from the Moon by the Soviet Luna 16 probe.
Mare Nectaris - the 'Sea of Nectar', is one of the smaller volcanic lava plains, with a diameter of about 360km & depth of about 1km. It is located in the centre of an 680km diameter impact basin which was formed 3.8 - 3.9 billion years ago.
At the southern end of the mare, there is the 128km-wide lava filled crater Fracastorius, with the northern boundary with Sinus Asperitatis featuring the prominent Theophilus & smaller Mädler crater.
Mare Nectaris ia another of the maria to feature a higher density region called a mascon ('mass - concentration') where gravity increases at the centre of the impact crater.
Mare Humboldtianum - the 'Sea of Alexander Von Humboldt', is named after the Prussian polymath of the same name. The mare's location at the Moon's northeast limb means that it isn't always visible due to the Moon's libration (the 'wobbling' of the moons apparent view from Earth due to the eccentricity of the Moon's orbit & the slight inclination between the Moon's axis of rotation and the angle normal to its orbital plane around Earth).
The Mare's basin is approximately 3.8 - 3.9 billion years old, and the lava filled region is 3.4 - 3.7 billion years.
Mare Imbrium - the 'Sea of Showers', is thought to have formed from a collision, 3.9 billion years ago, between the Moon and a proto-planet approx 250km in diameter. Basltic lava later filled the crater to form the mare we see today.
Mare Imbrium has a diameter of approx 1,145km & is the largest of the maria to be associated with an impact crater. When the crater was first formed, it's thought that it had a depth of 100km deep, but the floor of the basin bounced back upwards immediately afterwards. Today the basin has a depth of 12km with about 5km of mare material.
A gravitational high mass concentration ('mascon') from the impact was identified in the mare by the Luna Orbiter spacecraft in 1968.
Mare Vaporum - the 'Sea of Vapours', is a lava filled basin or crater with a diameter of about 242km.
Manilius crater can be seen on the right hand side of the mare, with Montes Apenninus & Montes Haemus to the north. Also in this image from Rod Levene, Rima Hyginus can be seen in the south of the mare. This rima (or rille) is an area of seismological fissures or cracks in the lunar surface.
Mare Humorum - the 'Sea of Moisture', is a lava filled impact crater about 390 - 425km across, approx 3.9 billion years old. At the centre of the crater the lava depth is thought to over 3km deep, and the force from the impact created a high density mass concentration ('mascon') with higher than average gravity.
On the north edge of the mare, the crater Gassendi can be seen.
Palus Epidemiarum - the 'Marsh of Epidemics', is an area flooded by balsatic lava approximately 200-250m deep, with a maximum depth of 750m.
This image was taken with a hand-held phone-camera, through the eyepiece of a NexStar 127 SLT.
At the northern tip of the march are two adjacent craters, Campanu and Mercator, to the left of the Rupes Mercator escarpment. Below them & to the left is the large flooded crater Capuanus, with the smaller Ramsden crater, being prominent to the south of the mare.
On the left hand side of the mare, you can also see the rough Rupes Kelvin region and the Promontorium Kelvin mountain. The later is about 25km × 43km wide.
Mare Nubium - the 'Sea of Clouds', is an irregular region filled by a basaltic lava flow without any distinct boundaries. It has a diameter of approx 750km and possibly is part of the same lava flow which filled Mare Cognitum, Mare Insularum & parts of Oceanus Procellarum.
The most promininet crater, to the west, is Bullialdus, with another large crater Pitatus on the southern edge being filled with lava.
Mare Cognitum - the 'Sea that has Become Known', is a lunar mare with a diameter of approx 370km. Before 1964, it was included as part of Mare Nubium, but gained its Mare Cognitum name after the 1964 American lunar probe Ranger 7 crashed into it's surface. The probe was the first to successfully transmit close-up images back to Earth of the Moons surface.
Sinus Roris - 'Bay of Dew' is basaltic lava plain between the top of Oceanus Procellarum and Mare Frigoris. In this image, the most prominent crater seen is Harpalus.
The borders of this feature are somewhat indistinct.
Lacus Mortis - the 'Lake of Death', is a hexagonal shaped plain of basaltic lava flow, situated between Mare Frigoris to the north and Lacus Somniorium to the south. It has a diameter of about 159km.
The most prominent crater visible in this image is the 40km diameter Bürg, which was formed by an impact 800 million years ago.
Lacus Somniorum - the 'Lake of Dreams', is the largest basaltic lava plain to be described as a 'lake' as opposed to a 'sea' (mare). It borders onto Mare Serenitatas and Lacus Mortis, and is somewhat irregular in shape.
It has an area of approx 70,000 km2.
Mare Insularum - 'Sea of Islands', is a region filled with basaltic lava at the edge of Oceanus Procellarum, between the Kepler and Copernicus craters.
Mare Frigoris - 'Sea of Cold', is a lunar mare in the far north of the Moon stretching from east to west for 1,400km, between Sinus Roris and Lacus Mortis. It has an average width of 250km.
The major crater to the north of the mare, with large ejecta rays is the 124km diameter Goldschmidt.
Oceanus Procellarum - 'Ocean of Storms' is the Moon's largest balsatic feature, stretching more than 2,500km north-south. It's basalt layer is thought to be between 1.33 - 3.4 billion years old.
The ocean was formed by ancient volcanic eruptions of lava that filled the low-lying areas with magma, but there is evidence in surrounding rock deposits that suggest a massive impact took place much earlier. Another hypothesis proposes that the feature was formed by heating & cooling of the surface by internal processes.
Rock samples froom the 2020 Chinese Chang'e-5 mission, were dated to around 1.963 billion years, suggesting that there has been volcanic activity about 1 billion years later than expected. This is surprising as it's thought that the Moon would have not retained enough heat for volcanism to occur at that time.
Schickard Crater is approx 212km in diameter and 3km deep. It's wall edges & southern floor are pock-marked with smaller crater impacts, and the crater has been partially flooded with lava. The northern & southern floors are very dark with lighter lava visible in the centre of the crater. Schickard is approx. 3.8 - 3.85 billion years old and was named after the German astronomer Wilhelm Schickard.
The crater to the south, which appears to have a raised floor level, is Wargentin which is nearly filled to it's brim with lava.