Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-12-13
BY THOMAS r. HENRY.

Sunset on the moon has been photo
graphed successfully over more than a
quarter of a million miles of empty
space by astronomers Of the Carnegie
Institution.
The first moving pictures of phenom-
cha on the surface of another heavenly
body were shown trustees of the insti-
tuition meeting here today. The film, it
is announced, was taken with a moving
picture camera using the l00-inch re-
f1ector telescope at the Mount Wilson
observatory in California as lens.
The moons day lasts $50 hours, the
time required for this satellite to turn on
it's axis. Consequently, sunset proceeds
very slowly. The reflector telescope lens
was focused on the moons surface for
more than five hours to produce this
picture but to make the movement viSu-
al it has been reduced so that it is
shown in minute and a half.
What the observer sees are the creep
ing shadows of the moons great craterS
growing longer and longer as the sun
sinks below the horizon, plunging one
half of the body into long night in
which the temperature sinks very low,
probably to the neighborhood of abso-
lutte zero, since the moon has no atmoS-
phere to hold the heat. This absence
of atmosphere makes the shadows very
sharp, so that their progress can easily
be followed.
Photograph New Discoveries.
The film was taken in connection
with the work of the moon committee
of the Carnegie Institution, engaged in
an extensive program Of scientific
studies relating to the pale orb of night.
While the moon is the present limit OF
the moving picture camera, the 100-1nch
telescope itself extends mans vision so
far into space that it now is possible to
study objects approximately 100000
100000 miles away, the trustees were
informed by Mount Wilson Observatory
astronomers. They were shown recent
photographs of one of the remotest OBJ
jects yet found in the heavens, a cluster
of spiral nebulae or island universes in
the constellation Coma Bernices taken
through the telescope. Each Of these
nebulae may be a group of millions of
stars comparable in magnitude to the
whole Milky Way galaxy of which the
earth is an insignificant part.
Another miracle" of photography
demonstrated to the trustees by Mount
wilson observatory aSCrOOOInerS was b
picture of laboratory table and appa-
ratus made in total darkness, using
only the invisible infra-red radiation.
A plate, made especially sensitive to
infra-red radiation by treatment with
a dye emulsion known as neo-cyanine,
was exposed in the dark room for seven
hours while infra-red rays were focused
on the objects.
While the use Of invisible waves from
the other end of the spectrum long has
been used in photography, it was ex-
planned that this is the first time mira
red radiation has been used successfully
and it is expected to have important
applications in astronomy and physics.
It has commercial importance in mo-
ton picture photography since plates
made In day time with the infra-red
appear as night scenes.
Important studies reported by Car
negie investigators in other fields of
science included one of the great lions
which lived in the United States during
the last ice age. Almost complete
skeletaI remains Of this ancient king of
beasts have been recovered from Cali
fornia tar pools. These great cats were