21–40 of 46 results
Lava Bumps Near Copernicus

Celestial Objects to Observe

A Little Guide to Lunar Domes

With this week's waxing Moon, we set off to explore its volcanic past with a look at a dozen intriguing lunar domes.

Phases of the Moon


What are the Phases of the Moon?

The phases of the Moon are determined by the relative positions of the Moon, Earth, and Sun.

Mystery Dark Spot?

Explore the Night with Bob King

Are You Game for April's Lunar Observing Challenge?

With astronomy being celebrated around the globe this month, join the fun by participating in a unique lunar observing challenge: track down 20 features once thought to show evidence of change from weather, geology, and even life.

Smartphone holder for Moon imaging


Expert Tips for Basic Lunar Imaging

It's easy to take high-quality images of the lunar disk.

A Full Crescent Moon

Explore the Night with Bob King

Meet the Meager March Moon

Baptized in the fire of yesterday's total solar eclipse, a very young crescent Moon emerges into the night sky.

Old rock sprinkled atop new

Explore the Night with Bob King

Blue Moon Rayed-Crater Blowout

Like "catching some rays"? This weekend's Blue Moon invites us to explore the beauty and dazzle of crater rays, the tracks left by powerful impacts in the not-so-distant past.

Explore the Night with Bob King

How to See All Six Apollo Moon Landing Sites

Walk in the astronauts' footsteps as you explore the places they visited in the heyday of Apollo program. Use these helpful maps to start you on your way.

Explore the Night with Bob King

Crazy About Concentric Craters

With the Moon riding high this week, what better time to look for its three best-known yet enigmatic "ring" craters? We welcome back the waxing Moon this week. It's a chance for many of us to put dark-sky targets on the back burner and give some love to she who lights the night.…

Round makes jagged when the light is right


Shadows on the Moon Make a Point

Fooled by shadow play into thinking lunar mountains were pointy pinnacles? Learn why we often see them that way.

Crescent cradles the 'old moon'

Stargazing Basics

Earthshine, the Moon's Darker Side

With a subtle beauty all its own, the earthshine we see glowing in the lunar night invites us to consider Earth's many connections to the Moon.

Celestial Objects to Observe

Take a Moon Walk Tonight

Explore the Moon with binoculars or a telescope.

Lunar 100


The Lunar 100

As the moon wanes in the gibbous phase in the nights to come, see if you can find and observe some of 100 of Charles Wood's classic lunar hit list, including craters, basins, mountains, rilles, and domes.

Rising Moon

Celestial Objects to Observe

Where Does the Phrase "Once in a Blue Moon" Come From?

We'll see a "blue Moon" next Friday, but what does that mean? From the Middle Ages to the game of Trivial Pursuit, a folklorist explores the origin of the phrase.


Glimpse the Moon's Far Side

You can see 9% more Moon than just what's on the near side — thanks to lunar libration.

The crater Tycho seen by Lunar Orbiter 5.

Celestial Objects to Observe

Tycho: The Metropolitan Crater of the Moon

Tycho is the most conspicuous crater visible near full Moon, shining brilliantly and radiating great long rays. But the rays from Tycho that partially encircle the full Moon are not distributed equally in all directions.

Plato proves the point

Celestial Objects to Observe

The Mysteries of Plato

The crater Plato is one of the superstars for observers of the Moon. It's big, conspicuous with its dark floor ringed by a bright rim, and long a subject of speculation, and controversy.

The craters Messier and Messier A


Messier on the Moon

Oblique impact resolves the mystery of one of the most bizarre crater pairs on the Moon: Messier and Messier A. Previous explanations for this crater pair ranged from imaginative to fantastical. All were wrong.

Mare Nectaris


Rings and Things

Mare Nectaris is the smallest of the circular maria on the Moon; lavas extend only 350 kilometers from shore to shore. But the Nectaris basin is beautifully defined by the spectacular Altai Scarp, which forms the southwestern rim of the basin.

Moon phases in perspective

Celestial Objects to Observe

A Month of Moonwatching

Whatever its phase, the magnificent Moon has lots to offer.

The Straight Wall at last quarter


Ancient Thebit and Huygens's Sword

The absolute best example of a lunar fault is the Straight Wall. This well-known lunar feature is a long thin line that never fails to impress; even through a small telescope it's a fascinating sight.