CLEMSON, South Carolina – Clemson University scientist Donald Liebenberg has personally witnessed and researched 26 total solar eclipses over the past 60-plus years.

Liebenberg, who has been an adjunct professor in the College of Science’s department of physics and astronomy since 1996, has literally travelled all over the world to enter the path of totality of solar eclipses. He has studied them from the ground, on ships in the middle of oceans, and in airplanes. He even watched one eclipse from the cabin of a Concorde supersonic airliner, where he was able to remain within the window of totality for an astounding 74 minutes.

Liebenberg’s sixth eclipse, chronicled below, was Nov. 12, 1966 in an airplane almost 40,000 feet above the South Atlantic off the coasts of Argentina and Brazil. His last one was March 9, 2016 aboard the cruise ship MS Vollendam off the coast of Indonesia.

All told, Liebenberg has spent more than two and a half hours in totality, which surpasses anyone else on Earth.

The upcoming Aug. 21, 2017 event over Clemson will mark Liebenberg’s 27th eclipse. He has also witnessed several other eclipses that were nearly – but not quite – in the path of totality.

Today is the sixth chronicle of all 26 of Liebenberg’s eclipse adventures on our Eclipse Over Clemson blog.

Please sit back and continue to enjoy this amazing adventure.

This map shows all 26 total solar eclipses that Donald Liebenberg has witnessed in person.

This map shows all 26 total solar eclipses that Donald Liebenberg has witnessed in person. Image courtesy of eclipse-chasers.com

THE NSF COMES CALLING

Eclipse No. 6: Nov. 12, 1966        Totality: 2 minutes, 40 seconds

Where: Over the South Atlantic         Weather conditions: clear

By Donald Liebenberg

The 1966 eclipse occurred off the coasts of Argentina and Brazil and was especially interesting because it passed over the South Atlantic Anomaly, a region where the our planet’s radiation belts dip to as low as 120 miles above the Earth and subject satellites and other spacecraft to higher-than-normal doses of radiation.

Dr. Donald Liebenberg

Dr. Donald Liebenberg

During the eclipse, our team again studied the corona aboard an NC-135 aircraft. But we weren’t the only object in the sky that day. Several rockets, laden with instrumentation, were also launched in this area. So as you might imagine, we made careful plans to avoid their trajectories.

The equipment on our NC-135 included magnetic measurements. Our 10-inch objective lens was incorporated into a more traditional telescope. The steering of this telescope required a lot of force, so Bob Lang and Ed Brown of the Los Alamos National Laboratory (LANL) developed hydraulic push rods and control systems. Fiber optics at selected positions on the focal plane were integrated to feed a photomultiplier tube. This specific observation did not fare well, but overall we accomplished our mission and acquired a good deal of valuable data from the 1966 eclipse.

After the eclipse, I attended a meeting in connection with the Astronomical Society in Michigan. While there, I was invited to attend another meeting about the 1970 solar eclipse that would cross over Mexico and much of the east coast of the United States. During this same time, our second child was born.

After the meeting in Michigan, I received a telephone call from Bob Fleischer of the National Science Foundation asking if I knew of someone who would come and serve at NSF as program director for Solar Terrestrial Research (STR). Brashly and naively, I responded, “Have you thought of me?” Of course, he wouldn’t have called otherwise. I agreed to consider his offer and talk this over with management at LANL, where I had been employed since 1961.

Eclipse team members are shown in the cockpit of the NC-135. The telescope barrel is at right.

Eclipse team members are shown in the cockpit of the NC-135. The telescope barrel is at right. Photo courtesy of Donald Liebenberg

Dr. Ed Hammel, my group leader at LANL, initially seemed okay with me receiving an appointment to NSF. But later he was resistant, so we ended up agreeing that I would be “loaned” to NSF for 1½ years. In 1967, my wife and two children moved from Los Alamos, New Mexico, to a Virginia suburb near Washington, D.C.

During my time in the nation’s capital, I created and oversaw programs that involved neutron and cosmic ray observations, solar telescope observations over a wide spectral region, and night-sky auroral observations that included rocket shots to insert material into the earth’s upper atmosphere to study magnetic fields.

Because of all this, I grew as a scientist. My reputation apparently grew, as well, because my opinion was sought many times, including whether to keep open the Poker Flats Research Range in Alaska (I supported), establishing the Big Bear Solar Observatory in California (I supported the expected reduced local air turbulence), and encouraging the cosmic ray people to work together with the other parts of the STR programs (I went to their meeting in Banff, Canada, and held a “rump” session to enhance cooperation). I also represented the United States at the closing ceremony of the “International Year of the Quiet Sun” held in London in the prime minister’s garden.

Meanwhile, we knew that a total solar eclipse would occur over Russian in 1968 and that a group of U.S. scientists wanted to attend. I asked NSF management how to obtain clearance for the scientists and their equipment to travel to the eastern side of the Ural Mountains, a region where not many U.S. citizens had ever gone because of the tenseness of the decades-long Cold War between powers in the Eastern and Western blocs. So I pleaded my case with an official in the U.S. State Department, who said he would look into it. Obviously, he honored his word because the Americans did end up receiving clearance.

This is a photograph of the interferometer optics. Point P1 from the corona is focused on the image plane P2 but may be enhanced by in-phase interference or reduced by out-of-phase interference. Photo courtesy of Donald Liebenberg

This is a photograph of the interferometer optics. Point P1 from the corona is focused on the image plane P2 but may be enhanced by in-phase interference or reduced by out-of-phase interference. Photo courtesy of Donald Liebenberg

Before the 1968 eclipse occurred, the Russians invaded Czechoslovakia, which made me wonder how this might affect the U.S. eclipse expedition. But as it turned out, our scientists were permitted to go and then return with all of their valuable equipment, which to me was a grand example of the respect science has garnered among nations – even those that angrily disagree over other issues.

After a busy 1½ years at NSF, I began planning my return to LANL. Dr. Tom Jones, the director of atmospheric science at NSF, called me in and asked if I would like to stay. I respectfully declined. But to this day, I have great appreciation for the dedication and competency of the federal workforce.

On my return to LANL, I settled back into programmatic efforts and started research at high pressures with Dr. Bob Mills. Only one person at LANL, Dr. Bob Fowler, ever asked me to come and talk about my experience at NSF. Otherwise, I was treated as if I had never left LANL. Los Alamos was just beginning to adapt to the the notion of extending beyond its protective boundaries, which until then had fostered the view that if it was worth doing, we would do it at LANL and nowhere else.

Up next: Eclipses 7-9, June 12