10 of the best features to observe on the Moon

Our planet’s only natural satellite, the Moon has enough features to keep astronomers busy for a lifetime. Here are 10 lunar highlights to get you started.

Tycho crater on the Moon, by FERNANDO OLIVEIRA DE MENEZES

The source of our ocean tides and the only other world that humankind has so far set foot upon, the Moon seems a familiar and tangible place. A quarter of Earth’s diameter and just a quarter of a million miles away, The Moon is 100 times closer than Venus.

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Given its proximity, brightness and large apparent size, it’s easy to see why the Moon has enchanted humankind for centuries.

More lunar observing guides:

A mosaic image of the Moon captured by the Galileo spacecraft, showing colour on the lunar surface. On the upper left is Mare Imbrium; middle left is Mare Serenitatis; lower left is Mare Tranquillitatis, and the dark patch towards the bottom is Mare Crisium. Credit: Stocktrek Images
A mosaic image of the Moon captured by the Galileo spacecraft, showing colour on the lunar surface. On the upper left is Mare Imbrium; middle left is Mare Serenitatis; lower left is Mare Tranquillitatis, and the dark patch towards the bottom is Mare Crisium. Credit: Stocktrek Images

Pre-telescopic observers noticed an unchanging pattern of darker patches that would later become known as lunar maria, or ‘seas’, because they were assumed to be vast bodies of water.

They act as a Rorschach test for different cultures: the face of the ‘Man in the Moon’ observed in Western tradition, the ‘Rabbit’ pounding rice of East Asian folklore, or the ‘Lady Reading a Book’ from the southern hemisphere, to give just three examples.

The reason we see the same lunar features staring back at us is because the Moon has a synchronous rotation with respect to Earth, meaning that spins once on its axis in the same 27.3 days (the sidereal month) it takes to complete an orbit of our planet.

Four hemispheric views of the Moon constructed from images taken by NASA's Lunar Reconnaissance Orbiter. Credit: NASA/GSFC/Arizona State University
Four hemispheric views of the Moon constructed from images taken by NASA’s Lunar Reconnaissance Orbiter. Credit: NASA/GSFC/Arizona State University

Observing the Moon

The Moon is the ideal place to begin your observing odyssey because it is big, bright and covered with amazing detail (for more on this, read our guide How to observe the Moon).

But the thing that surprises most novice observers is the variation it holds. Though the same hemisphere faces Earth at all times, what you can see on the Moon changes from night to night (find out more about the lunar phases in our article Why does the Moon’s appearance change?).

You may be forgiven for thinking that full Moon is the best time to examine our close companion – not so.

While this is a good time to see the long, bright rays of ejecta surrounding prominent craters such as Tycho, the high altitude of the Sun in the lunar sky means no shadows are cast, resulting in a washed-out view of the Moon.

Tycho crater on the Moon, by FERNANDO OLIVEIRA DE MENEZES
Tycho crater. Credit: Fernando Oliveira De Menezes

In general, the best time to view a given lunar feature is when the terminator, the demarcating line that separates lunar day and night, is nearby.

This is the region where the Sun is either rising or setting, where crater rims and mountain peaks stand out in stark relief, casting inky black shadows across the lunar surface that exaggerate their presence.

Those further from the terminator show hardly any shadows and are harder to make out.

Observing the Moon with the naked eye it’s easy to see the progression of lunar phases, full disc effects such as earthshine and the major lunar seas.

The Apennine Mountain Region on The Lunar Surface across the Terminator, by Peter J Williamson.
The Apennine Mountain Region on The Lunar Surface across the Terminator, by Peter J Williamson.

If you observe the Moon through binoculars it will increase the detail you’ll see: as well as dark seas, you’ll now be able to spot individual craters and large mountain ranges, especially close to the terminator.

The smallest craters you’ll be able to pick out will depend on how still you can hold your binoculars, but a pair of 7x50s should comfortably reveal features down to about 50km across.

A telescopic view of the Moon is amazing and one that never gets old. At low magnifications, the amount of detail visible is breath-taking, especially close to the terminator where relief shadows really help to emphasise the detail.

Upping magnification by using shorter focal length eyepieces will get you in closer and give you opportunity to ‘roam’ around the lunar landscape.

best features to observe on the moon

Below are 10 of the best features to observe on the Moon. You can use our Moon map above to help you locate each of the features. For more on the science of the Moon and how to observe it, visit our dedicate Moon webpage.

And if you want weekly moonrise times and lunar phases delivered directly to your email inbox, sign up to the BBC Sky at Night Magazine e-newsletter.

Top 10 features on the Moon

1

Hadley Rille

Hadley rille. Credit: Pete Lawrence
Credit: Pete Lawrence

Equipment needed to see it Large scope

Famous as one of the features explored by the Apollo 15 astronauts, Hadley Rille is also a great target to look for with a large telescope. Under suitable illumination it appears as a little meandering black line near the northern end of the lunar Apennines.

2

Crater Grimaldi

Grimaldi Crater. Credit: Steve Marsh
Credit: Steve Marsh

Equipment needed to see it Binoculars

Visible to the naked eye, this dark, 173km-wide basin reveals lots of detail through binoculars and telescopes, including eroded walls, ridges and low hills.

3

Crater Copernicus

Copernicus crater on the Moon, by John Brady.
Credit: John Brady.

Equipment needed to see it Small scope

At the heart of a huge system of bright rays that spread for hundreds of kilometres, this 93km-wide crater has a distinctive terraced rim.

4

Crater Plato

Crater Plato on the Moon, by Marc Delaney
Credit: Marc Delaney

Equipment needed to see it Small scope

This beautiful 109km-wide crater lies nestled among the jagged landscape near the northern edge of the Mare Imbrium. It has a smooth floor and is surrounded by interesting features, including Rima Plato and the Montes Teneriffe.

5

The Lunar Apennines

Lunar Apennines, by Ian Peck
Credit: Ian Peck

Equipment needed to see it Small scope

The Apennines mountain range stretches over 900km across the lunar surface. It is particularly striking when lit from the side – when the peaks cast huge, inky black shadows onto the surrounding landscape.

6

The Vallis Alpes

Vallis Alpes. Credit: Oliver Schneider / CCDGuide.com
Credit: Oliver Schneider / CCDGuide.com

Equipment needed to see it Small scope

Cutting through the lunar Alps, the 130km-long Vallis Alpes is one of the most interesting features on the Moon’s surface. This valley can be spotted with even a small telescope.

7

Crater Gassendi

Crater Gassendi, by Fernando Oliveira De Menezes
Credit: Fernando Oliveira De Menezes

Equipment needed to see it Small scope

A fascinating 110km crater on the northern edge of the Mare Humorum. Under the right light, you’ll be able to see a superb network of rilles on its floor.

8

Rupes Recta

Rupes Recta. Credit; Michael Karrer / CCDGuide.com
Credit; Michael Karrer / CCDGuide.com

Equipment needed to see it Small scope

Best known as the Straight Wall, this 110km-long fault reaches over 270m above the lunar surface. Look for a thin black line near to crater Birt.

9

Mare Crisium

Mare Crisium, by Mark Large
Credit: Mark Large

Equipment needed to see it Binoculars

This 620x570km lunar sea is one of the most distinctive features on the Moon. Located close to the eastern limb, it’s clearly visible to the naked eye as a dark oval patch. Unlike the other seas, the Mare Crisium is completely detached. Its dark, smooth-looking floor has a higher boundary that shows fantastic shadows as the terminator approaches and crosses the sea.

10

 Craters Ptolemaeus, Alphonsus and Arzachel

Ptolemaeus, Alphonsos and Arzachel by Gary Thompson
Credit: Gary Thompson

Equipment needed to see it Small scope

These three imposing craters sit close to the centre of the Moon’s near side. The largest of them, Ptolemaeus, has a smooth floor that is pockmarked with lots more tiny craters.

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What are your favourite features to observe on the Moon? Have you managed to captured any photos of them? Get in touch with us by emailing contactus@skyatnightmagazine.com or via Facebook, Twitter and Instagram.