Sky and Telescope - December 2017 - 54

lunar feature commemorates Mellan,
but Pierre Gassendi, the scientist who
asked him to make the drawings, has a
splendid crater.
Perhaps the most accomplished artist
fascinated by the Moon was John Russell. Having been repulsed by the poor
quality of many existing lunar drawings,
he produced more than 200 sketches
over 40 years, combining them into gores
for a glorious lunar globe (1797) and
later two maps of the Moon (1805). His
works represented the lunar surface more
realistically than any previous attempt.
The ﬁrst astronomer to devote much
of his career to the Moon was Johann
Hieronymus Schröter, who studied
Venus (S&T: Jan. 2017, p. 52) and other
worlds, but who is most famous for his
assiduous observations of the Moon over
nearly 20 years. Although inelegant, his
drawings initiated our modern interest
in studying individual features. Schröter
investigated rilles, mare ridges, and the
q The rim of the lunar crater Schröter is
incomplete - in keeping with its namesake's
fragmentary lunar observations made over
two decades.

lunar limb, and he measured elevations
of mountains and craters. His results
were published in two massive books
titled Selenographische Fragmente - a recognition that he never combined his 75
detailed drawings into a complete map.
The rim of Schröter's lunar crater, like
his studies, is fragmentary.
A German duo, Wilhelm Beer and
Johann Mädler, published their magisterial lunar book and map in the
mid-1830s. Beer, a wealthy banker and
amateur astronomer, owned the observatory that Mädler used to observe and
map the Moon, completing the work in
two years.
Mädler's approach and results were
scientiﬁc. Based on observations, he
drew many conclusions that stand
today: The Moon has no atmosphere,
maria are not liquid, rays have no relief,
craters are much larger than terrestrial
volcanoes, and rilles are unlike Earth's
rivers. He also realized that some peaks
at the lunar south pole are always in
sunlight (S&T: June 2017, p. 53). Mädler
famously concluded that the Moon was
"no copy of the Earth."
Craters bearing the names Beer and
Mädler are, appropriately, 10 km and

10 km

D E C E M B E R 2 0 17 * S K Y & T E L E S C O P E

28 km wide, respectively. The female
mathematician and astronomer Wilhelmine Witte used Mädler's map to
create a lunar globe in 1838, and their
meeting led to Mädler marrying her
daughter. There's no lunar crater named
Witte, but she's the namesake of a volcanic feature on Venus.
Julius Schmidt, who ﬂourished from
the 1840s through the early 1880s, is
a textbook example of lunar addiction.
As a young teen he obtained a copy of
Mädler's map, and the Moon became
his scientiﬁc focus for the rest of his
life. Schmidt's obsession culminated in
the publication in 1878 of the largest
(77½ inches across) and most detailed
map of the Moon. He compulsively
counted its 32,856 craters to demonstrate his map's overwhelming superiority compared to all of its predecessors.
By the early 1900s a growing number
of lunar maps carried different names
for the same craters. An English woman,
Mary Blagg, working under the guidance of Samuel A. Saunder, published a
concordance of lunar nomenclature in
1912, and in 1935 she and Karl Müller
published the International Astronomical Union's ﬁrst catalog and map of the
Moon. The catalog proved very useful;
the map was ugly. Blagg, who did nearly
all of the work, is remembered with a
crater merely 5 km wide - while her
male colleagues have craters with diameters of 22 and 44 km, respectively.
In the 1960s and early 1970s Gerard
Kuiper and his colleagues completed
the era of telescopic lunar mapping by
publishing four comprehensive photographic atlases. Craters are named for
Kuiper on the Moon, Mars, and Mercury. His colleague, the renowned lunar
expert Ewen Whitaker, died in 2016
(see https://is.gd/Whitaker), and I hope
his name will appear on a crater after
the required three-year waiting period
has passed.
¢ CHARLES WOOD, who considers
himself a certified lunatic, heads the
International Astronomical Union's Lunar
Nomenclature Working Group.

N ASA / LUN A R RECONN AISSA NCE ORBITER

DECEMBER 2017 OBSERVING
Exploring the Moon

https://www.is.gd/Whitaker

Sky and Telescope - December 2017

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