Evening star., 1953-04-06
Rockets 100 Miles Up
Record Valuable Dotu
Atmosphere Found Is Thinner
Than Finest Vacuum Here
BY Thomos R. Henry


The atmosphere 100 miles above the
earth has a density of only ten mil
lionth of a gram per cubic meter.
This is far more tenuous than the
finest vacuum ever attained at the
earth'S surface. The finding repre-
sents the highest direct physical meas
urement yet obtained with instruments
attached to rockets.
This has just been reported to the
American Geophysical Union by its
standing committee on problems of the
upper atmosphere.
Gravitational Process.
The rocket flights during the past
five years, according to the report, have
made necessary considerable revision
Of ideas previously reached by deduc-
tions from indirectly obtained data.
Significant changes in the composition
Of the atmosphere, for example, have
been found in the region from 80 to so
miles above the earth, compared to
that at sea level. The ratio of the
rare gas helium to the abundant heavy
gas nitrogen is twice as great. The
neon-nitrogen ratio Is about 20 per
cent greater. This is the first clear
evidence for gravitational Sedimenta-
ton of atmospheric gases.
Twenty-seven observations of winds
at attitudes of from 20 to 80 kilometers
have been made. These winds appear
to be eaSterly in summer and westerly
in winter. One measurement shows q
speed of 120 miles an hour. Fifty-mile-
high clouds have been detected.
Intensity of the suns radiation in
the invisible ultraviolet and x-ray re-
gions has been found to vary consider
ably. The ultraviolet region indicates
a temperature Of about 5000 degrees
centigrade for the suns surface. In
the soft x-ray region temperature Of
more than 5000 degrees centigrade Is
indicated, probably due to the fact
that this radiation comes from some
layer considerably below the surface.
r.
Speeds of Gulf Stream. 49,.
An intensive study of current veloci-
ties of the Gulf Stream now is being
carried out by the Navy photographic
Office.
Results Of one years work have
yielded data which makes 1t possible
to cut as much as three hours from
the sailing time Of 15-knot ships, such
as most oil tankers, between Gulf oil
ports and New York, according to a
report to the American Geophysical In
stitute here.
The study is being concentrated on
the Gulf Stream course between the
Florida Straits and Cape Hatteras, ac-
cording to the report. Within this area
the variations in the speed Of the great
river in the ocean as enormous. It
Is being determined for approximately
every is miles. It is by taking advan-
tage Of the higher speed areas that
ships can make the great time saving.
This work, according to the report,
is part Of an oceanographic survey Of
the coastal waters Of the United States
being conducted in cooperation with
the Coast and Geodetic Survey, the
Office of Naval Research, and various
universities. The two specially equipped
ships of the photographic Office, the
San Pablo and Rehobeth, have made
10 cruises, chiefly in the Atlantic. since
they were commissioned In 1948, and
have covered more than 100000 miles.
chiefly in the Western Atlantic. During
this time approximately TOO observa-
ton stations have been occupied.