Planets and Moons  ID: 4253

Moon Phase and Libration, from the Other Side

A number of people who've seen the annual lunar phase and libration videos have asked what the other side of the Moon looks like, the side that can't be seen from the Earth. This video answers that question. (Update: The video was selected for the SIGGRAPH 2015 Computer Animation Festival.)

Just like the near side, the far side goes through a complete cycle of phases. But the terrain of the far side is quite different. It lacks the large dark spots, called maria, that make up the familiar Man in the Moon on the near side. Instead, craters of all sizes crowd together over the entire far side. The far side is also home to one of the largest and oldest impact features in the solar system, the South Pole-Aitken basin, visible here as a slightly darker bruise covering the bottom third of the disk.

The far side was first seen in a handful of grainy images returned by the Soviet Luna 3 probe, which swung around the Moon in October, 1959. Lunar Reconnaissance Orbiter was launched fifty years later, and since then it has returned hundreds of terabytes of data, allowing LRO scientists to create extremely detailed and accurate maps of the far side. Those maps were used to create the imagery seen here.

In the first of the two viewpoints, the virtual camera is positioned along the Earth-Moon line at a distance of 30 Earth diameters from the Moon and 60 ED from the Earth. The focal length is equivalent to a 2000 mm telephoto lens on a 35 mm SLR, making the horizontal field of view about one degree. The view is consistent with what you might see through an amateur telescope at these distances.

In the second view, the virtual camera is much closer to the Moon, only 1.2 ED, versus 31 ED from Earth. The camera focal length has been reduced to 80 mm, giving a 25° horizontal field. The result is an Earth that appears much smaller, more closely resembling the way it would look to the eye from the surface of the Moon.

 

Related


For More Information

LRO Mission


Visualization Credits

Ernie Wright (USRA): Lead Animator
David Ladd (USRA): Producer
John Keller (NASA/GSFC): Scientist
Noah Petro (NASA/GSFC): Scientist
Please give credit for this item to:
NASA's Scientific Visualization Studio

Short URL to share this page:
http://svs.gsfc.nasa.gov/4253

Mission:
LRO (Lunar Reconnaissance Orbiter)

Data Used:
LRO/LROC/WAC 643nm High Sun Global Mosaic
JPL DE421
LRO/LOLA/Digital Elevation Map

This item is part of these series:
Narrated Movies
LRO - Edited Features
SIGGRAPH 2015

Goddard TV Tape:
G2015-013 -- A View From The Other Side

Keywords:
SVS >> Albedo
SVS >> Elevation data
SVS >> HDTV
SVS >> Laser Altimeter
SVS >> Lunar
SVS >> Moon
SVS >> LRO
SVS >> Lunar Reconnaissance Orbiter
SVS >> LOLA
SVS >> LROC
SVS >> Lunar Topography
SVS >> Lunar Elevation Map
SVS >> Solar System >> Moon >> Lunar Surface
NASA Science >> Planets and Moons