April 1-30, 2016

Explore some of the fascinating features on our Moon.

For GAM2016, we will be running a series of Observing Challenges, developed by The Astronomical League. Whether you are a complete novice to astronomy or a seasoned veteran there will be something for you! Some of the challenges can be done in a night and some will take the whole month. 

If you are a sidewalk astronomer or part of an astronomy club you might like to run events to help people complete the challenges. If are planning an Observing Challenge event, don't forget to register your event!

Discuss your observations, ask and answer questions and meet fellow astronomers working on these challenges from around the world in the forum.

Share your photos from this challenge with us and the world on Facebook, or Tweet using #GAM2016 hashtag (@gam_awb). 

Lunar Explorations 

The search for change on the Moon – a search in vain.

Developed by John Goss of the Astronomical League

People have often fancied that the moon was an active world, even harboring life. Many observers, both professional and amateur, have believed that they stumbled onto to visual evidence suggesting changes occurring on the moon perhaps from vulcanism, perhaps due to life.

In this challenge you will be observing various features on the surface of the Moon that past observers mistakenly believed indicated active changes on the Moon. To help you with your observations, you can find an interactive map of the Moon here. Image of Moon and observers above by Babak Tafreshi.

Share your progress on this challenge with us and the world on Facebook, or Tweet using #GAM2016 hashtag (@gam_awb).

The Astronomical League has also provided a map (PDF) of each feature to help you find them.

Feature 

Best Observing Dates

Observation Notes

Between the craters Walther and Gauricus.

Best seen evening: April 16 and 17
Best seen morning: April 28 and 29

1671. Several times, Giovanni Domenico Cassini thought he saw a misty formation, perhaps a cloud

Gassendi, crater.

Best seen evening: April 18 and 19
Best seen morning: April 1 and 2

1776. English astronomer William Herschel imagined that the shading variations on the crater floor were caused by the changing shadows of a vast forest of trees that were several times taller than those on Earth.

Hevelius, crater.

Best seen evening: April 20 and 21
Best seen morning: April 2 and 3

1787. German observer Johann Hieronymous Schroeter suspected that a volcano recently formed in the Hevelius crater.

Alhazen, crater.

Best seen evening: April 10 and 11

1791. Schroeter saw changes in the definition of the crater that he thought were possibly due to mist or vegetation.

Two-thirds of the distance from Eratosthenes to Schroeter in Sinus Aestruum.

Best seen evening: April 15 and 16
Best seen morning: April 28 and 29

1822. Bavarian observer Franz von Paula Gruithusien saw the layout of a great lunar city, Wallwerk.

Sinus Iridum.

Best seen evening: April 18 and 19
Best seen morning: April 1

1837. During the Great Moon Hoax, newspaper writer Richard Adams Locke reported that rational beings were said to live there.

Messier and Messier A, craters.

Best seen evening: April 11 and 12
Best seen morning: April 23 and 24

1855. Some observers, led by the renowned observer the Reverend Thomas William Webb, saw a change in their respective configurations.

Cichus, crater in Mare Nubium.

Best seen evening: April 16 and 17
Best seen morning: April 29 and 30

1859. Rev. Webb thought it had enlarged its diameter since Schroeter observed it seventy years earlier.

Fracastorius, crater.

Best seen evening: April 12 and 13
Best seen morning: April 25 and 26

Circa 1870. French astronomer Jean Chacornac. Fragmentary walls believed to indicated the moon once experienced ocean erosion.

Plato, crater.

Best seen evening: April 17 and 18
Best seen morning: April 27 and 28

1869. English amateur astronomer William Radcliffe Birt encouraged his colleagues to closely examine the flat floor of Plato for any signs of change.

Linne, small crater.

Best seen evening: April 14 and 15
Best seen morning: April 26 and 27

1866. Johann Frederich Julius Schmidt, followed by others, thought that crater Linne had been damaged or transformed.

Hyginus N, near crater Hyginus along Rima Hyginus.

Best seen evening: April 14 and 15
Best seen morning: April 26 and 27

1877. Hermann Klein, Director of the Cologne Observatory, found a dark patch near Hyginus crater, one that hadn’t been visible in earlier observations.

Theophilus, crater.

Best seen evening: April 12 and 13
Best seen morning: April 25 and 26

Circa 1900. Suspected snowstorms on the central peak were glimpsed by William Henry Pickering.

Plinius, crater.

Best seen evening: April 13 and 14
Best seen morning: April 24 and 25

Circa 1900. Suspected snowstorms on the central peak were glimpsed by William Pickering.

Alphonsus, crater.

Best seen evening: April 15 and 16
Best seen morning: April 27 and 28

Circa 1900. Pickering attributed indistinct, dark areas on the crater floor to changing vegetation. He believed that he also saw snowstorms on its central peak.

Bullialdus, crater.

Best seen in evening: April 17 and 18
Best seen in morning: April 29 and 30

Circa 1900. Suspected snowstorms on the central peak were glimpsed by William Pickering.

Mons Pico, lone mountain.

Best seen evening: April 17 and 18
Best seen morning: April 27 and 28

Circa 1900. Suspected snowstorms on the peak of this isolated mountain were glimpsed by William Pickering.

Montes Recti, straight mountain range.

Best seen evening: April 17 and 18
Best seen morning: April 27 and 28

Circa 1900. Some observers saw it as an artificial construct. Suspected snowstorms were glimpsed by William Pickering.

Eratosthenes, crater.

Best seen evening: April 16 and 17
Best seen morning: April 28 and 29

1924. William Pickering interpreted shading changes on the crater floor as being due to vegetation growth and migrating swarms of insects.

O'Neil’s Bridge, mistaken formation.

Best seen evening: April 10 and 11
Best seen morning: April 23 and 24

1953. New York Herald Tribune science editor John J. O’Neill reported that he observed a twelve mile long natural bridge at the edge of Mare Crisium near the intersection of Promontorium Olivium and Promontrium Lavinium, just east of Proclus crater. Some believed it to be artificial, others saw nothing.

 

Sources:

Moore, Patrick, Guide to the Moon, 1953, Eyre and Spottiswoode Publishers
Webb, Rv. TW, 1962, Celestial Objects for Common Telescopes, 6th revision, Dover
Sheehan, William; Dobbins, Thomas, 2001, Epic Moon, Willman Bell
Wood, Charles A., The Modern Moon, 2003, Sky Publishing
Rukl, Antonin, Field Map of the Moon, 2005, Sky Publishing
Birren, Peter, Objects in the Heavens, 2011, Birren Design