Sky and Telescope - June 2017 - 53

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AVA NI SOA RES, BOT TO M: G EORG E TA RSOUDIS

Malapert
Massif

Cabeus is a little easier to spot. In 2009,
NASA's LCROSS probe crashed onto its
permanently shadowed ﬂoor, discovering near-surface deposits of water and
other volatiles (S&T: Feb. 2010, p. 28).
Your best near-term chance to spot
some of these far-southern features
comes on June 5th to 7th, when the
south pole of a waxing gibbous Moon is
tipped a little less than 6° toward Earth.
Observing pics near the north pole
is far easier because the topography is
much ﬂatter and appears less cluttered
with craters and mountains. The view
at lower right shows the longest and
easiest-to-see peak of eternal light. The
bright ray crater at far left is Anaxagoras - ignore it. Instead, look toward the
right at Scoresby, a fresh, somewhat
larger (56-km-wide) but not-as-bright
crater at 78° north. A distinguishing
feature is the small bright crater on its
inner rim.
Immediately poleward are the
overlapping, ﬂat-ﬂoored twins Challis
and Main. Continuing north, look for
another ﬂat-ﬂoored crater Gioja (42 km
wide, 83°N). Beyond that are prizes not
often seen: Byrd (94 km, 85°N) and
Peary (70 km, 89°N). The actual north
pole is on the brightly illuminated far
wall of Peary - it is nearly constantly
draped with sunlight.
A very favorable north-polar libration
- just under 7° - occurs on May 24th.
Unfortunately, the Moon is then a hairthin waning crescent only 1.3 days from
new. You might try one day earlier, May
23rd, when the libration is closer to 6°.
In Flammarion's day, the pics de
lumière éternelle were romantic oddities,
but they could soon become valuable
real estate. Their summits are washed
with nearly constant grazing sunlight
that solar-cell arrays could use to
generate electricity for lunar bases. The
temperature would stay nearly constant
at roughly -50°C (-60°F), which is a
brutally frigid winter day in Alaska but
rather temperate for a lunar location.
The deep, permanently shadowed craters nearby likely contain enough water
to drink, irrigate crops, and break down

South Pole
M5

Cabeus

Malapert

Newton A

Newton
Short

Moretus

50 km

p South is up in this view of the south-polar terrain seen during an extremely favorable libration.
Malapert Massif and other high-standing peaks in this region receive nearly constant sunlight.

North Pole
Peary
Byrd
Gioja
Main
Challis
Scoresby
Anaxagoras
Goldschmidt

Barrow
50 km

p Thanks to smoother terrain overall, you'll have an easier time "crater-hopping" to the Moon's
north pole when favorable libration permits. The far rim of Peary enjoys nearly constant sunlight.

into hydrogen and oxygen for use as
rocket fuel. They could be the oases in
an otherwise completely arid land.
A recent investigation by Martin Elvis
(Harvard-Smithsonian Center for Astrophysics) and two colleagues suggests that
the uniqueness of these pics might lead
to a rush to claim them. The Outer Space
Treaty of 1967 states that the Moon
is the "province of all mankind" and
prohibits nations and corporations from
claiming ownership of lunar land.
But 50 years ago we had no detailed
knowledge of these polar peaks. Elvis

* Visit www2.lpod.org for more insights on viewing the Moon telescopically.

and his co-authors speculate that
their value as both energy and water
resources could lead to creative interpretations of the Treaty. For example,
one provision states that any lunar
station's "delicate scientiﬁc experiment"
would require others to keep away so as
not to interfere. So you might want to
get out your telescope and take a look
at this polar property before the "no
trespassing" signs go up.
¢ No matter where he ventures on
the Moon, Contributing Editor CHUCK
WOOD always prefers to explore locations where the Sun is up.
s k y a n d t e l e s c o p e .c o m

* JUNE 2017

http://www2.lpod.org http://www.skyandtelescope.com

Sky and Telescope - June 2017

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