Physicists planning big at the South Pole are facing a tough test of patience as the US National Science Foundation is forced to postpone the construction of new telescopes and neutrino detectors – probably for several years – due to pressing infrastructure problems.
The South Pole is the perfect place for astronomical research: the skies are clear and free of disturbing light sources, allowing telescopes to be used to study the afterglow of the Big Bang or to detect neutrinos, also known as ghost particles, in the ice. There is no doubt that these two major projects should be continued and expanded. The research teams involved would be only too happy to launch an upgrade of their respective experiments at Amundsen-Scott Station as soon as possible, with commissioning planned within the next five years.
But the National Science Foundation (NSF) seems to be throwing a wrench in the researchers’ plans. After the pandemic years, there are a number of urgent maintenance tasks at several Antarctic stations that need to be done before new projects can be approved, according to the NSF. These include raising the Amundsen Scott Station, which is sinking slowly but surely beneath the snow. Also, the storage huts for fuel, supplies and vehicles have been serving for 48 years and need to be reinforced. And last but not least, it is doubtful whether the power supply, which is secured by means of diesel generators, would even be sufficient for any new projects. At any rate, an increase in grid capacity is not easily possible in view of the logistical and safety challenges and cannot be implemented before 2040.
One project involved is “IceCube,” the world’s largest neutrino detector, which involves scientists from around the world, including the United States, Germany and Switzerland. Beginning in 2010, the project sank 5,160 spherical optical sensors the size of basketballs deep into the ice, detecting the faintly tiny particles from distant galaxies when they occasionally collide with atomic nuclei in the ice, causing them to glow with a dim blue light. In 2012, the researchers discovered the first, ultra-high-energy neutrinos and, out of sheer excitement, dubbed them Ernie and Bert. Last year, the team registered an additional 79 neutrinos that came from the not-too-distant galaxy known as NGC-1068.
Now with IceCube-Gen2, the physicists plan to add 9,600 optical sensors to the detector, increasing the volume of ice used for the experiment from one cubic kilometer to eight cubic kilometers. This would allow more neutrino sources to be identified.
The new CMB-S4 telescopes will measure temperature and polarization variations of microwave light over much of the sky to search for ripples in space-time. Featured in the image is the South Pole Telescope. (Photo: Brad Benson, University of Chicago, Fermilab)
The other project deals with the Cosmic Microwave Background (CMB), which investigates the after-effect radiation of the Big Bang. It contains abundant clues about the origin and structure of the universe. The planned $840 million expansion, called “CMB-S4,” will add one 5-meter and nine 0.5-meter telescopes at the South Pole. Two additional 6-meter telescopes will be installed in Chile. In addition, the existing South Pole telescopes will have to be raised because, like the station, they are in danger of disappearing in the snow.
From the expansion, the CMB team expects to discover fire-wheel-like vortices, so-called primordial B-modes, which would be a signal for gravitational waves rippling through the early universe. This would allow them to prove that the newborn cosmos experienced an exponential growth spurt.
But until the infrastructure problems are resolved, neither project can proceed. The U.S. Congress has already approved $60 million in funding for the measures, and the NSF will also contribute matching funds over the next two years, but work still might not begin before the end of 2026. It would take two to three years to implement the measures. For the two science projects, it means that construction of the new facilities cannot begin until 2028 or 2029 at the earliest.
If this long-term delay indeed occurs, the CMB team fears that its research will be overtaken by a Japanese project that also plans to search for primordial B-modes with a space probe in 2028. The IceCube team, on the other hand, is concerned about an exodus of staff.
A few days ago, the United States Antarctic Program started to prepare a master plan for the South Pole Station. Hopefully, this will bring a little more clarity for the two large-scale project teams.
Julia Hager, PolarJournal
Featured image by Jeff Capps / National Science Foundation, CC BY-NC-ND 4.0
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