Imagine the Universe!
Imagine Home  |   Ask an Astrophysicist  |  
Ask an Astrophysicist

The Question

(Submitted March 02, 1998)

Is there any night time on the Moon? Is the Moon's daylight the same as the Earth's daylight or is it brighter?

The Answer

The moon orbits the earth with a period of four weeks ( a month) and during the orbit it always has the same side facing the earth. So this means that on the moon there is day and night, but they are both two weeks long instead of 24 hours.

The Moon's daylight is brighter and harsher than the Earth's. There is no atmosphere to scatter the light, no clouds to shade it, and no ozone layer to block the sunburning ultraviolet light.

The nights are also brighter, at least on the side of the Moon near to us. The night is lit up by sunlight reflected from Earth, while the night on Earth is lit up by sunlight reflected from the Moon. Earth is much bigger than the Moon, and Earth is also more reflective (with its clouds and oceans, it reflects more light than the dark Moon rocks). Earthlight on the Moon is much brighter than Moonlight on the Earth.

Hope this helps,
Jeff Silvis and David Palmer
For Ask an Astrophysicist

Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See for help on other astronomy Q&A services.

Previous question
Main topic
Next question

Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.

The Imagine Team
Acting Project Leader: Dr. Barbara Mattson
All material on this site has been created and updated between 1997-2012.

DVD Table of Contents
Educator's Index