Antarctica may have some of the most extreme weather on Earth, but it’s an ideal environment for astrophysicists who want to study deep space. Scientists from the Industrial University of Santander in Bucaramanga, Colombia, relied on the rugged Fluke 1625-2 GEO Ground Earth Tester — and invaluable customer service from Fluke specialists — to take critical measurements at a prospective site for their new radio telescope.
During the expedition, the team:
- Received specialized recommendations from Fluke experts to adapt their equipment for brutally cold temperatures and unique, challenging conditions.
- Collected reliable ground resistance measurements in temperatures colder than -40° C (-40° F) — surpassing the 1625-2’s own specification limit of operating down to -10° C (14° F).
- Captured a vital measurement on Union Glacier for the first time, paving the way for future scientific research.
BACKGROUND
Dr. Julian Rodriguez, an astronomer at the Industrial University of Santander in Bucaramanga, Colombia, embarked on a month-long expedition to Antarctica in December 2024. As an astronomer, his research focuses on detecting and analyzing radio waves emitted from the early universe, just a few hundred thousand years after the Big Bang. These radio waves contain valuable information about the composition of the early universe and hold the key to understanding how our universe became the way it is today.
However, radio waves from this early event are incredibly difficult to detect. Picking up a signal from deep space requires little to no interference from nearby devices that emit radio frequencies. It’s nearly impossible to avoid interference in the modern world, given the abundant presence of tools like cell phones, microwaves, radio towers, and more.
Antarctica offers a prime location for radio observatories. The continent’s remote nature and low levels of interference from outside frequencies makes it perfect for detecting the faint, distant radio waves of the early universe. However, establishing an observatory in such a remote area provides many challenges — including finding the right area to place it.
Before astronomers can set up a new radio observatory on a site, they have to take soil resistivity measurements to make sure they’ve chosen the best location for telescope performance. These measurements have a two-fold benefit: they help establish a grounding grid for the telescope and allow researchers to model how rock, ice, and snow substrates will interact with the radio waves captured by the antenna.
The grounding grid provides necessary protection from damaging electrical surges caused by lightning and electromagnetic interference, while modeling reveals if a site will allow clean, undistorted reception of radio signals from the early universe. Researchers turned to the Fluke 1625-2 GEO Earth Ground Tester to take soil resistivity measurements and help establish the best location for the new observatory.
“In each laboratory where I work, I buy Fluke instruments, because we know how the quality of the equipment is and have confidence in the results,” Rodriguez said.
Determined to find a site in Antarctica for the new observatory, Rodriguez and his team set out to test locations near Bernardo O’Higgins station in the Antarctic Peninsula, which the Chilean army operates year-round. They also took excursions to Union Glacier, a more remote area with a singular tent camp that only operates one month out of the entire year.
CHALLENGES
The team quickly realized that the snow-covered areas around O’Higgins Station were unsuitable for ground measurements, as the surface consisted of compacted snow rather than solid ice. When they attempted to insert test probes, the snow shifted and melted, making it impossible to obtain reliable data. In response, the researchers explored rocky outcrops near O’Higgins Station and ultimately decided to move their efforts to Union Glacier Camp, located approximately 2,000 kilometers away, closer to the South Pole. There, the solid blue ice provided the stable and continuous foundation needed for establishing a future radio observatory.
Drilling into the glacier presented its own unique challenges, though. Ice cracked, causing the probes to lose contact with the ground. Sometimes, the holes the team members drilled weren’t large enough for the probes, which needed to burrow deep into the ice to measure resistance. Equipment would also freeze or stop working in such brutal temperatures – which reach -40° C (-40° F) and below. Cables attached to the 1625-2 would freeze, and Rodriguez and his fellow researchers sometimes had to heat up the tester batteries in their hands and with their breath to get them to work.
While the 1625-2 is rated to handle temperatures as low as -10 degrees C, its rugged nature made the researchers hopeful that the experts at Fluke could help them devise a solution to use the test kit in the even more extreme environment at Union Glacier. So they reached out to technical experts at Fluke and INTRONICA, a Fluke distributor, for advice on how to adapt their 1625-2 and its corresponding accessories to take grounding measurements at one of the most extreme environments on Earth.
IMPLEMENTATION
“They were just really interested in supporting us,” Rodriguez said. The experts went above and beyond, providing guidance at no additional cost to the research team. “It’s a thing you don’t find easily in the relationship between customer and provider,” Rodriguez said.
Rodriguez and his team came with two significant problems. First, the researchers were connecting accessories to the 1625-2 with a banana plug. However, the banana plug shrank in the cold, diminishing the connection to the tester. INTRONICA and Fluke specialists recommended pushing open the banana plug’s two metal prongs to strengthen the connection, which effectively solved the problem.
Second, and most critically, the researchers were struggling to establish solid contact between the probes and the ground. Every time the team tried to push the probes into Union Glacier’s ice, the ice cracked, diminishing the crew’s ability to take a reliable measurement.
The Fluke team offered a solution: salt water. Pouring a bit of brine into the drilled hole before inserting the probe made the ice more malleable, allowing the team to successfully insert a probe. “It changed everything,” Rodriguez said. “It was thanks to that that we could perform the measurement.”
RESULTS
The Fluke team’s advice came at a time when the stakes couldn’t have been higher. “We were in the very, very last opportunity to perform the measurement before we left Antarctica,” Rodriguez recalled. “The first measurements were the same: open circuit, open circuit, open circuit. So, at the very last try, I took my hammer and I started to push very hard on the probes.”
On the last try, the ground became just malleable enough from the brine that the probe finally slid in without shattering the ice. After dozens of failed attempts, the researchers finally got a grounding measurement with the 1625-2. “We were just ecstatic,” Rodriguez said. “We jumped happily and were dancing around the instrument. It was a very special moment for us, especially for me, because it was my third time in Antarctica trying to measure this parameter.”
Capturing a grounding measurement at Union Glacier wasn’t only significant for establishing the team’s new radio telescope – it also marked a milestone for Antarctic research. Rodriguez believes this was the first time a grounding measurement was ever taken at Union Glacier.
“It’s very important, not just for us, but for the scientific community that works in this field,” Rodriguez said.
Thanks to experts at Fluke and INTRONICA, the team was able to complete their measurements and plan for the next steps in their telescope project. “If we didn’t have this kind of support, for sure we’d come back to Colombia without the measurements,” Rodriguez said. They plan to return next year to verify parameters with the 1625-2, which will be their fourth time using the same instrument in this environment.
Enabling the device to work in one of the most remote, harshest areas on Earth was no small feat. Taking probe measurements became nearly impossible due to extreme temperatures and unpredictable ground conditions – plus the fact that researchers were miles away from civilization during their expeditions.
“If you have these kinds of issues, you are really alone out there. You have to have a solution,” Rodriguez explained. “And thanks to the Fluke team, we found the solution and we measured these parameters and we are really happy.”