# OUR MOON QUIETLY GROWS TO SUPERMOON SIZE

Tom Logsdon
“Hi diddle diddle,
The cat and the fiddle,
The cow jumped over the moon.
The little dog laughed,
To see such fun,
And the dish ran away with the spoon.”
My mother taught me that playful English nursery rhyme when I was about nine years old..
Notice how the poet who wrote it couldn’t think of anything more fanciful than having a living,
breathing creature ending up in the vicinity of the moon!
It took 300,000 of us a full decade of very hard work, but we did it! We sent two dozen
astronauts on the adventure of a lifetime and we brought all of them back alive. In 1961
President John F. Kennedy, youthful and exuberant and brimming over with confidence,
announced to the world that America’s scientists and engineers would—within a single decade
—land a man on the moon and return him safely to the earth. No cows need apply. But
potential human astronauts were bigly and hugely enthusiastic about their new opportunity
to fly through space to a different world.
By using the math and physics we had learned in school, we covered hundreds of pages with
with cryptic mathematical symbols to work out the details down to a gnat’s eyebrow.
We ended up hurling 24 American astronauts into the vicinity of the moon!. 12 of them
“kangaroo hopped“ on its surface.
Earlier this month, when the moon grew to its maximum apparent size, we were all reminded of
the excitement we felt during Project Apollo. Of course, the size of the moon did not actually
change, it merely moved up to its point of closest approach.
Systematic perturbations on the moon’s orbit coupled with rhythmic variations in its distance
from the Earth as it traveled around its elliptical orbit resulted in surprisingly large variations
in its apparent size and its brightness as seen from the Earth.
These distance variations, in turn, cause its observed diameter and its brightness to vary by as
much as 15 and 30 percent, respectively. When the moon approaches its maximum apparent
size and brightness, it is characterized as a supermoon. The biggest and brightest supermoons
are spaced out several decades apart.
My son, Chad, who participates in Special Olympics, used his cellphone camera to create the
two photographs that accompany this blog. He took the first picture at the crack of dawn
when the moon reached its maximum diameter at the edge of the parking lot at the Embassy
Suites Hotel in Lexington, Kentucky (population 360,000). He made the second photograph
12 hours later in my hometown of Springfield, Kentucky, ((population 2900). That second