Messier marathon is an attempt undertaken by amateur astronomers to find as many Messier objects as possible during one night. The Messier catalogue consists of 110 relatively bright deep space objects (galaxies, nebulae, and star clusters). The number of Messier objects visible in one night varies depending on the season and the location of the observer. At a latitude close to 25 degrees North it is possible to observe all Messier objects in one night. The only time of year that this is possible is during late March or early April. The reason for this is because at other times of year, some of the objects are in the sky only during daylight.

Typically an observer attempting a Messier Marathon will need to begin observing directly at sundown and work until sunrise to view all 110 objects. The objects must be viewed in more or less a prescribed order. This corresponds to the order in which the objects set below the horizon. An observer will start observing objects low in the western sky at sunset, hoping to view them before they disappear below the horizon. Then he or she will work eastward across the sky, viewing objects along the way. By sunrise, the successful observer will be observing the last few objects low on the eastern horizon, hoping to see them before the sky becomes too bright due to the rising sun.

Many astronomy organizations organize a star party to attempt a Messier Marathon every year. Observers are typically given a certificate for their hard work the morning after certifiying how many objects they found. For more information, please see the links below.

External links

• http://www.seds.org/messier/xtra/marathon/marathon.html