Waxing Crescent Moon: Second Lunar Phase Shows Off Craters Through Binoculars

Summary: March 2015's waxing crescent moon, which follows a solar eclipse and the spring equinox, also gives good binocular views of three craters.

waxing crescent moon, with Mare Crisium, captured Tuesday, Dec. 9, 2014, by Lunar Reconnaissance Orbiter (LRO): NASA Goddard Space Flight Center (NASA Goddard Photo and Video), CC BY 2.0 Generic, via Flickr

As successor to the new moon, the waxing crescent represents the second phase of the moon's eight phase monthly cycle. The second phase transitions into the third phase, the first quarter moon. March's waxing crescent follows the month's stunning new moon eclipse of the sun and welcome of the spring equinox on Friday, March 20. The first quarter's rising takes place seven days later on Friday, March 27, at 07:43 Universal Coordinated Time.

The eight phase lunar cycle is further distinguished by four primary and four intermediate phases. The waxing crescent initiates the intermediate phase. This first intermediate phase is sandwiched between the first primary phase, the new moon, and the second primary phase, the first quarter.

Waxing crescent aptly describes this transitory phase from the darkness, or invisibility, of the new moon to the half, or 50 percent, illumination of the lunar disk characteristic of the first quarter. Waxing denotes increasing. Crescent defines an arc shape narrowing into end points that are often termed as horns.

The waxing crescent is known popularly as a young moon. During this phase, the lunar illumination grows from a narrow crescent to 49 percent coverage, as viewed by Earthlings.

The viewer's placement above or below the equator determines which edge of the lunar surface is illuminated. In the Northern Hemisphere, the waxing crescent grows from the right outer edge inward. In the Southern Hemisphere, the waxing crescent grows from the left outer edge inward.

The waxing crescent is one of a pair of opposites in the moon's monthly orbital cycle of eight phases. Its opposite, which closes the cycle as the eighth and last phase, is the waning crescent. Known popularly as an old moon, the waning crescent features decreasing illumination, diminishing from 49 to 1 percent coverage.

Even though the moon is only partially lit during the waxing crescent phase, some of its craters have sufficient brightness and largeness to be discernible even via binoculars. Northern Hemisphere viewers easily may identify features of the southern highlands in the moon's southeastern sector.

Catharina crater honors Saint Catherine of Alexandria (ca. 282-305 CE). The crater is found at coordinates 18.0 degrees south 23.6 degrees east. Catharina crater exhibits pronounced dimensions of 3.1 kilometers in depth and 100 kilometers in diameter.

Located south of Catharina, Piccolomini crater is named after Italy's Sienese philosopher Alessandro Piccolomini (June 13, 1508-March 12, 1579) and is found at coordinates 29.7 degrees south 32.3 degrees east. Piccolomini features a widely terraced inner wall and displays prominent dimensions of 4.6 kilometers in depth and 88 kilometers in diameter.

To the south of Piccolomini, Janssen crater honors French astronomer Pierre Jules César Janssen (Feb. 22, 1824-Dec. 23, 1907). Found at coordinates 44.96 degrees south 40.82 degrees east, Janseen traces a distinctive hexagonal shape and has pronounced dimensions of 2.9 kilometers in depth and 190 kilometers in diameter.

As the moon fattens its crescent during its second phase, it lights the sky with a bright, youthful glow. The waxing crescent only requires binoculars from those Earthlings desirous of glimpsing surface details such as craters in the southern highlands of the moon's southeastern sector.

The increasing play of light across the waxing crescent's surface attests to the moon's easy visibility in its orderly, predictable orbit around the Earth and affirms the rewards of glancing skyward.

waxing crescent moon Tuesday, June 3, 2014; Mare Tranquillitatis and Mare Crisium above Mare Fecunditatis; Mare Nectaris, left of Mare Fecunditatis; arc of Catharina, Cyrillus and Theophilus craters along upper left shore of Mare Nectaris; Piccolomini about midway below Catharina and above Janssen craters: Neal Simpson (Nohrmal), CC BY ND-2.0 Generic, via Flickr

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

waxing crescent moon, with Mare Crisium, captured Tuesday, Dec. 9, 2014, by Lunar Reconnaissance Orbiter (LRO): NASA Goddard Space Flight Center (NASA Goddard Photo and Video), CC BY 2.0 Generic, via Flickr @ https://www.flickr.com/photos/gsfc/15799021157/

waxing crescent moon Tuesday, June 3, 2014; Mare Tranquillitatis and Mare Crisium above Mare Fecunditatis; Mare Nectaris, left of Mare Fecunditatis; arc of Catharina, Cyrillus and Theophilus craters along upper left shore of Mare Nectaris; Piccolomini about midway below Catharina and above Janssen craters: Neal Simpson (Nohrmal), CC BY ND-2.0 Generic, via Flickr @ https://www.flickr.com/photos/nohrmal/14155771240/

For further information:

Fuller, David. "Moon Maps." Eyes on the Sky > Moon.
Available @ http://www.eyesonthesky.com/Moon.aspx

Grego, Peter. The Moon and How to Observe It. Astronomers' Observing Guides Series. London: Springer-Verlag, 2005.

Harrington, Philip S. Touring the Universe Through Binoculars: A Complete Astronomer's Guidebook. Wiley Science Editions. New York; Chichester; Brisbane; Toronto; Singapore: John Wiley & Sons, Inc., 1990.

"Lunar Calendar March 2015." Calendar Canada > Lunar Calendar.
Available @ http://www.calendar-canada.ca/lunar-calendar/march/2015/

Marriner, Derdriu. "Waning Crescent Moon: Old Moon Signals End of Lunar Cycle via Completed Orbit." Earth and Space News. Wednesday, March 18, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/03/waxing-crescent-moon-second-lunar-phase.html

Wright, Ernie. "Moon Phase and Libration, 2015." NASA GSFC Scientific Visualization Studio > Planets and Moons. Dec. 9, 2014.
Available @ http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4236