Skip all navigation and jump to content Jump to site navigation Jump to section navigation.
NASA Logo - Goddard Space Flight Center + Visit NASA.gov
HOME PROJECTS RESOURCES SEARCH MAP

+ Advanced Search
Home
Home
View Most Recently Released Imagery
View Gallery of Imagery: A topical collection of SVS Imagery
Search Imagery by the keywords assigned to it
Search Imagery by the instruments that supplied data for a visualization product
Search Imagery by the series of visualizations that have been produced
Search Imagery by the scientist providing the data used in a visualization product
Search Imagery by the animator that created the product
Search Imagery by the identification number assigned to the visualization product
See other search options





  + RSS Feeds
  + Podcasts
blank image
Previous Animation Number   Next Animation Number
Moon Phase and Libration, 2012

Dial-A-Moon

Month: Day: UT Hour:



The animation archived on this page shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year 2012, at hourly intervals. Until the end of 2012, the initial Dial-A-Moon image will be the frame from this animation for the current hour.

More in this series: 2014 | 2014 South | 2013 | 2013 South | 2011

The jagged, cratered, airless lunar terrain casts sharp shadows that clearly outline the Moon's surface features for observers on Earth. This is especially true near the terminator, the line between day and night, where surface features appear in high relief. Elevation measurements by the Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO) make it possible to simulate shadows on the Moon's surface with unprecedented accuracy and detail.

The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 12 seconds, as it is in this animation, our changing view of the Moon makes it look like it's wobbling. This wobble is called libration.

The word comes from the Latin for "balance scale" (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon's disk and the location on the Moon where the Earth is directly overhead.

The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon's north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by more than 10%.

The most noticed monthly variation in the Moon's appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and is high in the sky at midnight. The third quarter Moon is often surprisingly conspicuous in the daylit western sky long after sunrise.

Celestial north is up in these images, corresponding to the view from the northern hemisphere. The descriptions of the print resolution stills also assume a northern hemisphere orientation. To adjust for southern hemisphere views, rotate the images 180 degrees, and substitute "north" for "south" in the descriptions.


Share: Share via E-mail E-mail   Share on TwitterTwitter
 
Other multimedia items related to this story:
     Moon Phase and Libration, 2011 (id 3810)
     Moon Phase and Libration, 2013 (id 4000)
     Moon Phase and Libration, 2013 South Up (id 4067)
     Moon Phase and Libration, 2014 (id 4118)
     Moon Phase and Libration, 2014 South Up (id 4119)

The phase and libration of the Moon for 2012, at hourly intervals. The full-resolution frames include an alpha channel.    The phase and libration of the Moon for 2012, at hourly intervals. The full-resolution frames include an alpha channel.
Duration: 2.4 minutes
Available formats:
  1920x1080 (60 fps) MPEG-4   464 MB
  1280x720 (60 fps) MPEG-4   200 MB
  1280x720 (30 fps) MPEG-4   106 MB
  960x540 (30 fps) MPEG-4   64 MB
  640x360 (30 fps) MPEG-4   31 MB
  1920x1080 (60 fps) Frames
  560x560 (60 fps) Frames
  216x216 (60 fps) Frames
  320x180     PNG           34 KB
How to play our movies


The phase and libration of the Moon during May and June, 2012. The wider angle and lower speed allow a view that includes the background stars and the Sun. The near alignment of the Sun, Moon, and Earth during the May New Moon creates an annular solar eclipse visible at high northern latitudes. The June New Moon isn't so near the Sun.    The phase and libration of the Moon during May and June, 2012. The wider angle and lower speed allow a view that includes the background stars and the Sun. The near alignment of the Sun, Moon, and Earth during the May New Moon creates an annular solar eclipse visible at high northern latitudes. The June New Moon isn't so near the Sun.
Duration: 4.0 minutes
Available formats:
  1920x1080 (30 fps) MPEG-4   195 MB
  1280x720 (30 fps) MPEG-4   108 MB
  640x360 (30 fps) MPEG-4   48 MB
  1920x1080 (30 fps) Frames (Comp)
  1920x1080 (30 fps) Frames (Moon)
  1920x1080 (30 fps) Frames (Stars)
How to play our movies


Waxing crescent. Visible toward the southwest in early evening.    Waxing crescent. Visible toward the southwest in early evening.

Available formats:
  3600 x 3600     TIFF       8 MB


First quarter. Visible high in the southern sky in early evening.    First quarter. Visible high in the southern sky in early evening.

Available formats:
  3600 x 3600     TIFF       9 MB


Waxing gibbous. Visible to the southeast in early evening, up for most of the night.    Waxing gibbous. Visible to the southeast in early evening, up for most of the night.

Available formats:
  3600 x 3600     TIFF     12 MB


Full Moon. Rises at sunset, high in the sky around midnight. Visible all night.    Full Moon. Rises at sunset, high in the sky around midnight. Visible all night.

Available formats:
  3600 x 3600     TIFF     16 MB


Waning gibbous. Rises after sunset, high in the sky after midnight, visible to the southwest after sunrise.    Waning gibbous. Rises after sunset, high in the sky after midnight, visible to the southwest after sunrise.

Available formats:
  3600 x 3600     TIFF     12 MB


Third quarter. Rises around midnight, visible to the south after sunrise.    Third quarter. Rises around midnight, visible to the south after sunrise.

Available formats:
  3600 x 3600     TIFF     10 MB


Waning crescent. Low to the east before sunrise.    Waning crescent. Low to the east before sunrise.

Available formats:
  3600 x 3600     TIFF       7 MB


New Moon. By the modern definition, New Moon occurs when the Moon and Sun are at the same geocentric ecliptic longitude. The part of the Moon facing us is completely in shadow then. Pictured here is the traditional New Moon, the earliest visible waxing crescent, which signals the start of a new month in many lunar and lunisolar calendars.    New Moon. By the modern definition, New Moon occurs when the Moon and Sun are at the same geocentric ecliptic longitude. The part of the Moon facing us is completely in shadow then. Pictured here is the traditional New Moon, the earliest visible waxing crescent, which signals the start of a new month in many lunar and lunisolar calendars.

Available formats:
  3600 x 3600     TIFF       6 MB


Visualization shows the phases and libration of the moon, 2012.    Visualization shows the phases and libration of the moon, 2012.

Available formats:
  Download     KEYNOTE 107 MB
  Download     POWERPOINT 107 MB

Short URL to This Page:http://svs.gsfc.nasa.gov/goto?3894
Animation Number:3894
Completed:2011-12-21
Animator:Ernie Wright (USRA) (Lead)
Producer:Chris Smith (HTSI)
Scientist:Richard Vondrak (NASA/GSFC)
Project Support:Joycelyn Thomson Jones (NASA/GSFC)
Platforms/Sensors/Data Sets:Clementine (Feb 26 to Apr 21 1994)
 LRO/LOLA/Digital Elevation Map (Aug 2009 to Sep 2011)
Series:The Moon
 LRO - Animations
Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio
 
Keywords:
SVS >> Clementine
SVS >> Elevation data
SVS >> HDTV
SVS >> Laser Altimeter
SVS >> Lunar
SVS >> Moon
SVS >> LRO
SVS >> Lunar Reconnaissance Orbiter
SVS >> LOLA
SVS >> Lunar Topography
SVS >> Lunar Elevation Map
SVS >> Solar System >> Moon >> Lunar Surface
NASA Science >> Planets and Moons
SVS >> Presentation
DEPC Metadata is available here.
 
 


Back to Top
Many of our multimedia items use the GCMD keywords. These keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0

USA.gov logo - the U.S. Government's official Web portal. + Privacy Policy and Important Notices
+ Reproduction Guidelines
NASA NASA Official:
SVS Contact:
Curator: