Evening star. [volume] (Washington, D.C.) 1854-1972, 1909-11-28
CRATERS OF THE MOON
Researches by Prof. T.. }. J.
See of the U. S. Navy.
ORIGIN OF THE SATELLITES
New Theory Applied to Obliquities
of the Planets.
PHENOMENA OF SOLAR SYSTEM
Luna Depressions Due to Impact OF
Smaller Bodies-Moon Cap
tured by Earth.
PHENOMENA OF SOLAR SYSTEM

SAN fRANAlOCo. odl., INONelIlDei -
Extending and completing his researches
on the 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. I. ]. j.
See, United States Navy, the astronomer
in charge Of the naval observatory at
Mare Island, gave tonight to the Astro-
nomical Society of the Pacific an ex-
PLANTATION of the origin of the craters OF
the moon. and then proceeded to apply
the new theory to the obliquities of the
planets. which, he said. overcame the
last difficulty in the way of the capture
theory recently advanced by him as
supplantng the nebular hypothesis Oh
Laplace.
Prof. See announced that the lunar
craterS were undoubtedly due to the III
pact of smaller satellites against the sur
face of the moon, and not to volcanic
action, as had been generally beleVeo
since the time of Calico. The view tnat
the lunar craters might be due to I'M
pact, he said, had occurred to Proctor
as long ago as 1873, and had been men
toned as "a curiosity by NeWcomb In 1910,
while it had been more fully developed
by DIR. G. X. Gilbert of the United states
geological survey in 1882 But the I'M
pact theory had never been accepted by
biologists or astronomers, and was not
mentioned in any recent works on astfon-
omy, SO great has been the force OF tradi-
tional opinion incllnlng 10 the oio 'oi-
canic theory.
Regarded as Decisive. :
Prof. See however, pointed out de-
tailed reasons which, he claims, were alb
so,utely decisive against the volcanic
theory and remarked that there would
now be less difficulty in seeing the truth
of the impact theory than formerly. be-
cause, he had recently proved that the
moon is not a part of the earth thrown
off by rapid rotation, but a planet captur-
cd from snace The new theory of the
capture of the moon, he said. had peen
favorably received 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 sup
posed the craters to be volcanic 1t was
| impossible to account for the depressions
where the craters stand. and no forces
directed from within could dig out the
circular trough about the peak In the
center. Then. too, the way the craters
lie over one another shows that they are
About the newer craters, as CopernlcuS
| Tycho, Aristarchus. etc. the bright rays
| radia ting in all directions snow that at
| the time of the collisions the force or the
impact was such that matter was melted
yaporjzed and driven out from these CEN
tiers in all directions. A satellite hitting
the moon might have Its temperature
raised to 1900 degrees or higher, and the
bright rays from the craters were due TO
the scattering of highly heated matter
Institutes a Comparison.
| The blazing flash seen in target prac-
| tice when a shot hits the target was ia
| miliar to officers of the military service.
and the flattening and spreading of the
| proiectile was such as to give peak IN
| the center of the mashed shell, while at
| the same time a rim is formed around 1t.
/ lust like that seen about the craters on
| the moon. But the shot fired In the
mightiest target practice on the earth IS
| as nothing compared to that in the heaN-
ems, where satellites from twenty TO htty
| miles in diameter had been hurled against
| the lunar surface with velocity or over
| a mile second, and thus produced blaz-
| ing CONGREGATIONS sometimes covering the
whole side of the moon.
| Prof. See pointed out that many OF the
| craters are largely covered with cosmlcal
/ dust. kind Of metallic or lithic ram,
which had fallen from such conf1agra-
| tions There is no air about the moon
| in which it could long remain suspended
He said that the moon had never mad
any seas or smaller bodies Of water and
| that the lunar mountains were entirely
dine to impact Of satellites against the
| surface. but thought that most OF the
| great collisions had occurred before the
moon was captured by the earth, and
therefore while the moon was sun re-
volying in the region now occupied by
| the asteroids The smaller asteroids are
| about the size of the falling bodies which
| have produced the larger lunar craters-
| from twenty to sixty miles across rms
| is about the size of the planet Eros
| which approaches nearer the earth thah
any other known planet.
Evidence Of Hard Knocks.
| 1.-THE roughness of the surface of our
moon shows how many hard knocks 1t
| has received in the past Every planet
| has gone through similar experience,
but those having atmosphere and oceans.
like the earth, have suffered such great
| geological changes that they have. long
since lost all trace of ancient battering.
while these indentations have survived on
| the airless 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 obliquties of the plan
| cts by the impact of satellites against
! their surfaces He said he had diScov
| erred the cause of the obliquities from
| the case of Jupiter, whose axis is nearly
perpendicular to the plane Of his orbit.
| At one time Jupiter's obiiquity was larg-
| or than that of the earth, or even Sat
urn % 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 it. In this way
| had arisen the small obliquity of Jupiter,
and a similar influence had acted upon
| the other planets.
Saturn's obliquity would practically dis
appear if that planet could gather in
| enough satellites to make the mass as
| large as that of Jupiter The obliquity
| of our earth. on which the seasons de-
pend. is smaller than that of Mars. and
/ prof See said that the obliquity of We
nus probably was smaller yet, not eX-
| ceedng 20 degrees. He ascribed the
| high obliouty of the systems of Uranus
and Neptune to the original positions of
! those planets, their equators never hav-
| ing been greatly tilted over by the cap
| ture OF satellites.
Pelted by Falling Satellites.
The small obliquity Of Jupiter gave the
| rue clue to the cause at work, and the
| face of the moon showed how all planets
/ had been pelted by falling satellites dur
| ing the immensurable ages involved in
| the development of our solar system.
which was originally of much greater
| dimensions than at present The solar
/ system was formed from a spiral nebula,
/ the outer border of which originally ex-
| tended to something like thousand times