“We are a way for the cosmos to know itself”
- Dr. Carl Sagan

IC 1396 (Mike Sherick)

Minor Planet Discovery

Size and Shape of Minor Planets

Variable Star Measurements

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The Science of ASLC (continued)

The Association of Lunar and Planetary Observers

ALPOMany of us can remember the thrill of our first view of the craters on the Moon, the four large satellites of Jupiter, the amazing rings of Saturn, and other celestial wonders. There can also be a thrill, or perhaps a feeling of satisfaction and achievment, in recording systematic observations having scientific value, surely including digital images, of our Solar Sustem neighbors. It is then of value to report such data to proper places for analysis and publication. Since 1947 the Association of Lunar and Planetary Observers has been encouraging and supervising such efforts. The email address of the hard-working Secretary is

The work of the ALPO is divided into sections: one for each bright planet, one for the Sun, several for lunar projects, one for Minor Planets (see Fred Pilcher's article here), one for planets beyond Saturn, and several others. Many of the sections furnish instructional materials and/or outline forms to make recording data easier.

The online location with many, many words is ALPO members receive a quarterly Journal in either a digital or old-style print format. There is also an annual conference: last year at Calgary and this year at Des Moines. All interested persons are welcome as members.

- contributed by Walter Haas (ALPO's founder)

ALPO Reprint of H. Percy Wilkins' Exquisite 300" Lunar Map is now available on-line

Thumbnail of Wilkins Moon MapsHugh Percy Wilkins was a British mechanical engineer and amateur astronomer who devoted many years of his life to observing and recording lunar features during the early to middle portion of the 20th century. He published many lunar maps including a 60 inch version (1924), a 200 inch map (1930), and a 300 inch map (1946 with revisions in 1951 and 1954). At the time of their release, the 300 inch maps were considered the culmination of the art of selenography.

Wilkins divided the Moon into 25 sections. These were published one at a time, plus a few special areas, in consecutive monthly issues of "The Strolling Astronomer" (also "Journal ALPO") during 1950-1952. The scale of the map version as there published was about 38 inches to the lunar diameter.

A special reprint of ALPO's quarterly journal, The Strolling Astronomer, featuring a 100 inch (i.e. 100 inches to the Moon's diameter) reproduction of Dr. Wilkins 300 inch lunar drawings, was published during the 1950s. ASLC is proud to make this historical masterpiece available.

Click here or on the image to download this classic work.