GEO 1013 – THE THIRD PLANET
E. R. SWANSON – SPRING 2009
TEXAS AND THE UNIVERSE
Cosmic Texas Institutions
McDonald Observatory is located in the
of west Texas, on top of
Mount Locke 6,809 feet above sea level.
There are no golden arches at this McDonalds, but
the observatory and its W. L. Moody, Jr., Visitors Center serves over 100,000 visitors
The observatory was founded as the result of a million dollar bequest from the
estate of William Johnson McDonald, a prosperous banker from Paris, Texas, who died in
After a "contest of wills" with distant relatives, the University settled for
That was enough to build an observatory, but two astronomical
UT had no astronomers and no technical expertise to actually build an
The solution was to joined forces with the University of Chicago. The
resulting telescope, with its
(2.1 meter) mirror
was dedicated in 1939.
the world's second largest telescope at that time, and it performed yeoman’s duties during
WW II while most large observatories ceased operations.
The University of Texas assumed
sole control of McDonald Observatory in 1962, and with the aid of NASA funding, added a
(2.7 meter) reflector telescope in 1969, the world’s third largest at that time.
Thousands of discoveries have been made at McDonald Observatory including
oxygen in the atmosphere of Mars, small amounts of water vapor on Mars and Venus, and
methane ice on Pluto's surface. McDonald also pioneered laser ranging experiments that
accurately measure the distance between Earth and reflectors left by astronauts on the
The observatory also has a 36-inch and two 30-inch reflectors telescopes and a 16-
foot millimeter-wave dish satellite dish to catch waves emitted by interstellar dust.
of antennae in eight straight lines known as the
is found at Marfa,
forty miles south of McDonald, where it detects wave lengths of roughly three feet that
come from quasars and galaxies with active nuclei.
Quasars exist (or existed) over ten
billion years ago and are (or where) objects of extreme power. Some emitted a thousand-
trillion times more energy than our Sun, yet they are so far away that if the Two-Mile
Telescope had been operating since the beginning of time, it wouldn’t yet have gathered
enough energy to burn a light bulb for a single second!
The latest addition to McDonald is
a modern instrument with ninety-one, 1-meter mirror sections, the equivalent of an
It was built “on the cheap” and not all of the 11 meters are usable (an
effective aperture of 9.2 meters), but it keeps McDonald Observatory a world-class
This super telescope was dedicated in the fall of 1997 and it is dubbed the
(or HET) after former Texas Lieutenant Governor Bill Hobby and
Pennsylvania State University benefactor Robert Eberly.
The HET telescope exceeds all