Lunar Observation Guide: Best Features to View Through Your Telescope

Image Credit: NASA/Apollo 11 – Lunar surface as seen during the Apollo 11 mission. Public Domain.

Why Start with the Moon?

The Moon is the perfect first target for any telescope. It’s bright enough to observe from light-polluted cities, it reveals new details at every magnification, and its surface changes dramatically with the lighting angle each night. Even a modest 60mm telescope will show craters, mountain ranges, and vast lava plains.

With NASA’s Artemis II mission targeting a crewed flyby of the Moon in early 2026, and Artemis III planning to land astronauts on the lunar south pole in the years ahead, there’s never been more reason to get to know our nearest neighbor.

Understanding Lunar Phases

The Moon completes a full cycle of phases every 29.5 days (a synodic month):

• New Moon: The Moon is between Earth and Sun — invisible, but the best time for deep-sky observing.
• Waxing Crescent: A thin sliver appears in the western sky after sunset. Look for “Earthshine” — the faint glow on the dark portion caused by sunlight reflecting off Earth.
• First Quarter: Half the Moon is illuminated. The terminator (shadow line) creates dramatic 3D relief on craters.
• Waxing Gibbous: More than half illuminated, heading toward full.
• Full Moon: Fully illuminated — bright but flat-looking because the Sun shines straight down on the surface, eliminating shadows.
• Waning Gibbous → Last Quarter → Waning Crescent: The cycle reverses, with the Moon rising later each night.

Best Time to Observe: The Terminator

Counterintuitively, the best lunar observing isn’t during a full Moon — it’s during crescent and quarter phases. The terminator — the line between light and shadow — is where the magic happens. Sunlight strikes the surface at a low angle, casting long shadows that reveal:

• Crater walls and central peaks in stunning 3D relief
• Mountain ranges with shadows stretching across the plains
• Rilles (ancient lava channels) and scarps (cliffs)

Key Features to Find

Image Credit: NASA/Apollo 11 – The Apollo 11 landing site in the Sea of Tranquility. You can identify this smooth, dark region through any telescope. Public Domain.

Maria (Seas)

The dark patches visible to the naked eye are ancient basaltic lava plains, misnamed “seas” by early astronomers:

• Mare Tranquillitatis (Sea of Tranquility): Where Apollo 11 landed on July 20, 1969.
• Mare Imbrium (Sea of Rains): One of the largest maria, bordered by the Apennine Mountains.
• Oceanus Procellarum (Ocean of Storms): The largest dark area, where Apollo 12 landed.

Major Craters

• Tycho: A young, prominent crater in the southern highlands with a dramatic ray system stretching across the entire visible face during full Moon.
• Copernicus: A stunning 93km-wide impact crater with terraced walls and central peaks — nicknamed “The Monarch of the Moon.”
• Clavius: One of the largest craters visible, 225km across, with a distinctive arc of smaller craters along its floor.
• Plato: A dark-floored crater on the northern edge of Mare Imbrium — its flat, lava-filled floor contrasts sharply with surrounding terrain.

Mountains and Valleys

• Montes Apenninus: A mountain range over 600km long with peaks reaching 5,400m — visible as a dramatic arc near first quarter.
• Vallis Alpes (Alpine Valley): A straight, 166km-long gash through the lunar Alps — stunning at moderate magnification.

Photographing the Moon

Lunar photography is the easiest entry point into astrophotography:

• Smartphone + telescope: Hold your phone up to the eyepiece (afocal method) for surprisingly good results. Phone mounts cost $15–25.
• DSLR/Mirrorless: Attach your camera to the telescope with a T-adapter. Use manual mode: ISO 100–200, and adjust shutter speed until the exposure looks right (typically 1/125s to 1/250s for a quarter moon).
• Video stacking: Record short videos and use free software like PIPP + AutoStakkert + RegiStax to stack the sharpest frames. This overcomes atmospheric turbulence and produces dramatically sharper results than any single photo.

Moon Observation Challenge

Track these features over a full lunar cycle to build your observing skills. The Astronomical League offers a Lunar Observing Program with 100 targets that will make you an expert on our nearest celestial neighbor.

Next in our series: Light Pollution and How to Find Dark Skies