NAMIBIA – THE IDEAL LOCATION FOR EXPLORING OUTER SPACE
Celebrate Namibia series
“The Gamsberg is one of the five prime destinations in the world to conduct astronomy from and it is the only one which is not developed as an astronomical observatory. ”
Namibia is an ideal location for research into astronomy and astrophysics. There are quite a number of reasons for that claim – and actually some interesting ones, says Dr Eli Kasai, Senior Lecturer and Head of Department at the University of Namibia’s Department of Physics, Chemistry and Material Science.
“To start with, Namibia has been identified as the ideal site to be part of the Event Horizon Telescope (EHT) because we are positioned at the right latitude to observe the centre of the Milky Way”, Dr Kasai explains.
Another reason for Namibia being an ideal location is the fact that “… in any given year we have quite a lot of nights without clouds.Compared to other parts of the world the percentage of cloud-free days in Namibia is high,” Dr Kasai says.
“As Namibia is sparsely populated and not highly industrialised, we have darker night skies. That is perfect for observations with optical telescopes.” Dr Kasai adds that the absence of radio interference makes Namibia also an ideal location for using radio telescopes.
Dr Kasai points out that in Namibia university research into astronomy and astrophysics is barely two decades old. Actual university research began rigorously with the advent of High Energy Stereoscopic System (H.E.S.S.) telescopes in 2002.
The H.E.S.S. observatory on the farm Gollschau, near the Gamsberg about 100 km southwest of Windhoek, consists of five Imaging Atmospheric Cherenkov Telescopes. H.E.S.S. is not only an acronym for High Energy Stereoscopic System but also honours the Austrian-born physicist, Victor Hess, who discovered cosmic rays. He was awarded the Nobel Prize in Physics in 1936.
Asked about future plans, Dr Kasai says there are some interesting projects in the pipeline, but progress has unfortunately been stalled by the global COVID-19 pandemic. “This includes adding more telescopes such as the Africa Millimetre Telescope (AMT) as part of the EHT network of millimetre-wave radio telescopes to observe black holes, also in our own galaxy.”
Furthermore there are plans to build Square Kilometre Array (SKA) outlier stations in Namibia. The SKA, the largest radio telescope project in the world, is mainly hosted by South Africa and Australia, with outlier stations in other countries. “Together they form what is called a spiral shape. It is a technical design to achieve the kind of unprecedented accuracy that SKA needs to be able to answer the science questions it is built for”, Dr Kasai explains. This includes research into where magnetism comes from and why the universe is expanding and why the expansion is accelerating as time goes by.
Four SKA sites have been identified in Namibia – two in the south with its vast empty spaces, one west of Windhoek on the same latitude and one northwest of Tsumeb. The first phase of the SKA is to be completed around 2026 – but as a result of the COVID-19 pandemic there are uncertainties when it will become operational.
“H.E.S.S. telescopes operate in the very-high-energy gamma ray spectrum and probe the most violent events in the universe, be it exploding stars or the monstrous centres of active galaxies,” explains Professor Michael Backes, Associate Professor in the Department of Physics, Chemistry and Material Science at the University of Namibia and Head of the H.E.S.S research group.
H.E.S.S. has made numerous contributions to prestigious scientific publications – not only astronomy journals, but journals for the whole scientific community. Major recent research includes studies about gamma ray bursts which were completely undetected until a few years ago, and the discovery of emissions from active galaxies. As Professor Backes says, research by H.E.S.S. found that the emission from active galaxies are not just coming from the very centre of those galaxies but along those extended plasma jets that shoot out into space.
The H.E.S.S. observatory has received prestigious prizes, among them the Descartes Prize of the European Commission which recognizes Outstanding Scientific and Technical Achievements Resulting from European Collaborative Research, and the Rossi Prize of the American Astronomical Society. The Rozzi Prize is awarded for “a significant contribution to High-Energy Astrophysics”.
Professor Backes says that although the global COVID pandemic has hampered the AMT project there has been quite some progress. “AMT is not just planned to be the first telescope to operate on millimetre waves on the African continent, but once it is constructed it will open up the Gamsberg to more astronomical observation.” First light for the AMT is planned for somewhere between 2024 and 2026.
The Gamsberg is one of the five prime destinations in the world to conduct astronomy from and it is the only one which is not developed as an astronomical observatory. The preliminary design report, including the technical specifications, as well as the Environmental Impact Assessment have already been approved. Feedback was provided in the EIA report on how to preserve the indigenous flora on Gamsberg during the construction of the telescope.