Omaha daily bee., 1909-11-29
ORIGIN OF CRATERS ON Moon
Prof. See, in Lecture, Says They Are
Caused by Impact Of Meteors.
CAPTURE THEORY GAINS SUPPORT
He Advances Argument that Satellite
IL Not Part of Earth, but a
Planet Acquired from
Space.

SAN FRANCISCO, Nov. 2s.-Extending
and completing his researches on ,he origin
Of the planets and satellites Of the solar
system, earlier accounts Of which were
made public in January and June Of the
present year, Prof. T. ]. j.. See, L. S. N,
tho astronomer in charge OF the naval OBJ
servatory at Mare Island, gave Saturday
night to the Astronomical Society Of The
Pacific, an explanation Of the origin Of the
c-aters Of the moon and then proceeded to
apply the theory to the obllquitica Of The
planets, which, he said, overcame the last
difficulty in tha way Of the Capture
theory recently advanced by him as sup
planting the nebular hypothesis Of Llpace.
Prof. See announced that the lunar
crnters were undoubtedly due to the i'm
pact Of smaller satellites against the sur
face of the moon, and not to volcanic
action, as had been generally believed,
since the time Of Calico. The view that
the lunar craters might be due to impact.
he said had occurred to Proctor, as long
ago as 1S72, and had Deen mentioned as
a curiosity by Newc5mJ in 1878; while 1t
had been more fully developed by DR.. g..
K. Gilbert of the United States Geological
SUI NNS III 1915 bQl llt impact theory naQ
never been accepted by biologists or az
tronomers, and was not mentioned in any
recent works on astronomy, so great has
been the force of traditional option in
ching to the old volcanic theory.
Capture Theory Gains upport
Prof. See, however, pointed out detailed
reasons which, he claims, were absolutely
decisive against the volcanic theory, and
remarked that there would now be less
difficulty in seeing the truth of the i'm
pact theory than formerly, because he had
recently proven that the moon is not a
part of the earth thrown off by rapid ro-
tation, but a planet captured from space.
The new theory of the capture of the
moon, he said, had been favorably re-
ceived by the scientific world, but it would
be Of still greater use in bringing to light
other discoveries, such as those announced
tonight.
DR.. See said the typical crater on the
moon was a very large circular depression
with steep walls inside and sloping walls
outside and a small peak in the. center,
with the top of it below the average level
Of the lunar surface. If any one supposed
the craters to be volcanic, 1t was impos-
sible to account for the depressions where
the craters stand, and no forces directed
from within could dig up the circular
trough about the peak in the center. Then,
too, the way the craters lie over one an
other shows that they are nothing but
satellite indentations. About the newest
cratera, as Copernicus, Tycho, Aristarchus,
etc, the bright rays radiating in all direc-
ton show that at the time of the collisions
the force of the impact was such that mat
ter was melted, vaporized and driven out
from these centers in all directions. A
satellite hitting the moon might have its
temperature raised to 1000 degrees or
higher, and the bright rays from the
%craters were due to the scattering of
highly heated matter.
Example in Target Practice.
TIL blazing flash seen in target practice
when a shot hits the target was familiar
to officers Of the military service, and the
flattening and spreading of the projectile
was such as to give a peak in the center
Of the mashed shell, while at the same
time q rim is formed around It, Just like
that seen about the craters on the moon.
But the shot fired in the mightIest target
practice on the earth is as nothing COM
pared to that in the heavens, where satel-
lites from twenty to fifty miles in dame
ter had been hurled against the lunar sur
face with a velocity of over a mile a sec
ond, and thus produced blazing conflagra-
lions sometimes covering the whole side
Of the moon.
Prof. See pointed out that many of the
~craters are largely covered with cosmical
dust, a kind of metallic or lithic rain.
which had fallen from such conflagrations.
There is no air about the moon in which
1t could long remain suspended. He said
that the moon had never had any seas or
smaller bodies of water, and that the lunar
mountains were entirely due to impact of
satellites against the surface, but thought
that most Of the great collisions had oc-
CURED before the moon was captured by
the earth, and, therefore, while the moon
was still revolving in the region now occu-
pied by the asteroids. The smaller aste-
roids are about the size Of the falling bod
les which have produced the larger lunar
craters-from twenty to sixty miles across.
This is about the size of the planet Eros,
which approaches nearer the earth than
any other known planet.
Lack of Air Preserves Effects.
THE roughness Of the surface of our
moon shows how many hard knocks 1t has
received in the past. Every planet has
gone through a similar experience, but
those having atmosphere and oceans, like
the earth, have suffered such great geo.
logical changes that they have long since
lost ali trace Of ancient batterlng, while
these indentatlons have survived in the air
less and waterless moon to show us the
terrific process by which worlds are
formed" declared Prof, See.
In a second paper presented tonight, DR..
See explained the obliquities OF the planets
by the impact Of satellites against their
surfaces. He said he had discovered the
cause Of the obliquitles from the case of
Jupiter, whose axis is nearly perpendicular
to the plane Of his orbit. AT one time
Jupiteris obliquity was larger than that of
the earth, or even Saturn. 2S degrees; but
as the greatest of the planets had gathered
In satellites moving about the sun in planes
having the average position Of the Jovian
orbit, the equator had been tilted down
almost into coincidence with II. In this
way had arisen the small obliquity Of Jupi-
ter, and a similar influence had acted upon
the other planets. Saturn's o~bliquity would
practically disappear IL that planet could
gather in enough satellites to make the
mass as great as that Of Jupiter. The
obliquity OF our earth. on which the sea-
sons depend, is smaller than that OF Mars,
-M