April 15 Lunar Eclipse from a Different Perspective: What Would an Astronaut See from the Moon?
April 10, 2014
A lunar eclipse is one of the easiest astronomical phenomena to observe without the aid of a telescope. Lunar eclipses are also relatively common, occurring about twice a year. In 2014, the first eclipse will occur on the night of April 14–15 and the second will occur on the night of October 8. When a lunar eclipse occurs, the Moon is moving through the Earth’s shadow. If there are clear skies in your area, you can watch the lunar surface darken, then slowly turn a bright red color over the course of a couple of hours. While watching the eclipse, you might ask yourself what it might look like if you (or your favorite astronaut!) were on the surface of the Moon instead of on Earth. View from the Nearside of the Moon |
During the eclipse, an astronaut would see the dark nightside of Earth slide in front of the Sun until it was completely rimmed with light. This spectacular ring of light was seen by Japan’s Kaguya spacecraft when it was in orbit around the Moon during an eclipse on February 10, 2009. While the ring of light dominates the astronaut’s view of the sky, the lunar surface underfoot and on the surrounding mountain peaks would be bathed in red light. This red coloring is due to Earth’s atmosphere acting as a lens, bending the Sun’s light and scattering blue light while allowing red light to pass through and eventually reach the lunar surface. Because Earth is blocking the Sun and most of its light from view, temperatures would begin to fall. During the June 15, 2011, lunar eclipse, the Diviner instrument onboard the Lunar Reconnaissance Orbiter observed the temperature of the lunar surface drop more than 100°. An astronaut’s spacesuit can accommodate the change in temperature, but his or her visibility would be affected. Low light levels might make it more difficult (but not impossible) to see and might affect depth perception. View from the Farside of the Moon |
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What would an astronaut exploring the farside of the Moon experience during a lunar eclipse? In short, nothing. Lunar eclipses occur when Earth is positioned between the Moon and the Sun. Because the farside of the Moon faces away from Earth, an explorer on the lunar farside would not see the Sun disappear or the lunar surface reddened, nor would they feel temperatures fall. Indeed, they would be completely unaware that an eclipse had even occurred. They would, however, be dealing with low light levels, because they would be in the midst of a 14-day long period of darkness — the lunar night — while the nearside was experiencing the eclipse. Techniques for living and operating in those nighttime conditions have been developed and, in some cases, simulated in lunar analog terrains. For example, in 2010, the NASA Desert Research and Technology Studies (Desert RATS) team simulated a 28-day mission to the Malapert Massif on the lunar farside, including the deployment of two rovers with astronauts during a lunar night. Operating without sunlight for power in future missions will be challenging, but is something that can be accommodated for short periods of time. |
For more information, visit
Center for Lunar Science and Exploration
NASA Solar System Exploration Research Virtual Institute
Lunar Eclipse Information, Multimedia, and Activities
Lunar Eclipse Seen from the Moon
The Five Best Things to See During a Lunar Eclipse, if You Were on the Moon
Last updated April 11, 2014