Evening star., 1963-12-31

ply crltlclzeo q decision to bob
in the 1930s. said there are two
schools Of thought about how
the moon was formed.
One theory. advanced by DR..
Urey, contends that the moon
accumulated from material
inside a vast gas-dust cloud.
and was later captured by the
earth. The other theory, older
than DR.. Urey's and only re-
Gently revived after a long
period Of unpopularity, is that
the moon was flung out Of q
rapidly rotating proto-earth in
the days before the world
solidified.
I When men get to the moon,
I predict there will be a big
controversy over which Of these
theories is right" he said.
II personally hope the first
process proves correct. because
II so. it will tell US about the
origin Of the solar system. If
the second turns out to be
right, it viii tell US nothing
very much about the origins
Of either the earth or the solar
system"
"a Little Bit Bored"
DR.. Urey confessed to being
"a little bit bored" with space
activity to date. Except for the
Mariner probes discovery that
Venus has no magnetic field,
mot one datum of interest to
me personally has come out Of
the space program"
He emphasized that this was
a personal feeling only, point
ing out that physicists found
great interest in the discovery
of the Van Allen Belt, the solar
wind and other radiation and
particle phenomena in space.
DR.. Urey's chief interest in
space relates to the moon.
about which nothing much has
been learned since the space
age began.
Sterilizing space probes
before sending them moonward
is not too important, DR.. UTey
said. His comment came in
answer to a question about a
change in project rangers
ground rules, accomplishing
the Importance Of spacecraft
sterility.
There's no reason to believe
there is or ever has been life
on the moon," DR.. Urey said.
H said that experince with
meteorites found on earth has
shown how difficult it is to be
absolutely certain that q body
from beyond the earth's atmos-
phere is absolutely uncontami-
mated and expressed hope that
some unsullied moon material
might be obtained early in the
exploration Of the lunar sur
face.
Another Story
The question Of contamina-
ton Of Mars is another story,
he said. That climate is widely
believed to harbor life-quite
probably the only abode of life
in the solar system-and most
scientists believe 1t will be
absolutely necessary to sterilize
space craft completely before
launching them for a Mars
landing.
Two spacecraft in the Marin
er series are be be launched
toward Mars IN October and
November Of 1854. They are
supposed to miss the planet by
about $4,000 miles and will not
be. subjected to the extreme
sterilization procedures that
will be applied to ars-landing
probes in the l970S.
| DR.. Urey, a chemist, dis
counted the possibility of nom
carbon-based life existing on
Mars or anywhere else.
I'VE know enough about the
chemistry Of the elements to
bee sure that only the chemis-
try Of carbon will give us the
complex thing we call life." he
said.
There are two forms of
carbon based molecules which
are mirror images Of each
other" They are generally
incompatible.
Matter of Chance
The form opposite to that
prevailing on earth might be
dominant on Mars, in which
case contamination from earth
would not be too important, he
said. But it is apparently a
matter of chance which molec-
ular form gets the upper hand:
and If the same form is prev
alent on both planets, it might
fbe difficult to sort the two
1ifA FlN-paaa