In Case You Were Wondering When African Countries Were Going to Join the 21st Century
They’re Way Ahead of You
If you’re one of those people who tends to ignore the news coming out of various regions across the African continent or dismiss Africa as a whole as primitive, war-prone, and lagging behind the so-called “first world,” this image should put that notion to rest.
No, it’s not a picture of a Christmas light buried in the snow. It’s an unprecedented image of the radio emissions being produced at the center of the Milky Way Galaxy covering six square degrees of the night sky (thirty times the area of the full Moon). The bright gem-like object near the center of the image is actually Sagittarius A*, a supermassive black hole. And that is only the beginning of the image’s revelatory majesty.
Also present, are various supernova remnants including one in nearly perfect spherical form, and the existence of hundreds of mysterious magnetic ‘filaments’ that have researchers scratching their heads.
This unbelievably clear image of the galactic center was made by the new MeerKAT telescope and published in the Astrophysical Journal a week ago by I. Heywood and a group of over a hundred researchers in association with the South African Radio Astronomy Observatory (SARAO) as part of an article (I. Heywood et al) describing in detail some of the problems and methods of research it has spawned.
With all of the hype — warranted though it may be — around space exploration, suborbital joyrides, and new technologically advanced space telescopes, it is easy to ignore the great new astronomical technology being devised and produced right here on Earth. Especially, it seems, if it is coming from the African continent. The MeerKAT’s unprecedented clarity and resolution should put that notion to rest.
Commissioned in 2018, the MeerKAT is the latest and most sophisticated member of the class of Very Long Baseline Interferometers (VLBI’s). The telescope array consists of 64 antennas (dishes), each 13.5 meters (44 feet) in diameter, spread over an area of 8 kilometers (5 miles) in northwestern South Africa.
Interferometry (the displacement or interference of light, radio or sound waves for use in various areas of physical research) began to be used widely in the latter 19th century. A form of interferometer was famously used by Albert Michelson and Edward Morley in 1887 to dispel the notion of the luminiferous ether, a mysterious light propagating medium championed by the likes of Christiaan Huygens, Sir Isaac Newton and Robert Boyle in the 17thcentury.
Michelson later devised some of the largest early optical interferometers, one of which was built and attached to the 100-inch telescope at Mount Wilson and used by Michelson and Francis Pease to measure the diameter of the red supergiant star Betelgeuse in the Orion constellation, as well as others.
Still later, the digital age enabled the development of larger optical interferometer arrays using multiple telescopes like the CHARA array and the twin Keck telescopes on Mauna Kea on Hawaii’s Big Island. The extreme light gathering capabilities of these modern telescopes has advanced scientific discovery and knowledge exponentially over the past half century.
The MeerKAT and its constituent arrays stand to propel us ever farther in our quest to understand the mysterious workings of the universe. It is only the initial phase of a much larger VLBI being spearheaded by South Africa and Australia that on completions sometime in the 2020’s will comprise thousands of antenna arrays around Australia, South Africa and eight other African and Island nations including: Botswana, Zambia, Namibia, Mozambique, Kenya, Ghana, Madagascar and Mauritius.
The Square Kilometer Array (SKA) as it is called, will have a collecting area of a million square meters with a resolution fifty times that of the Hubble Space Telescope whose iconic images of deep space helped to usher in the modern era of space exploration. It is a marvel of modern engineering brought to you, in part, by members of the scientific community of Africa!
1. I. Heywood et al. ‘The 1.28 GHz MeerKAT Galactic Center Mosaic’, ApJ, 2022