Elisabeth Lickindorf
South Africa pushed the frontiers of science this week, with the launch of new satellite measuring technology that can provide accurate measurements of the physical changes of sub-Saharan Africa for the first time.
It will allow South African scientists to monitor the potentially devastating El Nio effect, where ocean warming can raise sea levels by up to 30cm.
The launch of the new satellite laser ranging equipment named Moblas-6 means that the Hartbeestpoort radio astronomy observatory has analytical capabilities matched by five out of a worldwide network of 40 measuring stations.
Moblas-6 arrived on permanent loan from Nasa in late August. It is the only satellite ranging instrument in sub-Saharan Africa, and fills a huge gap by providing accurate information about the continent.
The Hartbeestpoort observatory will contribute crucial information about the rotation of our planet, and movements of the crust that cause volcanoes and earthquakes. In 1971 scientists could measure changes in the Earth’s dimensions to within a metre now such measurements are accurate to within 5mm.
Moblas-6 works by directing a fine beam of flashing, very short-duration pulses of green laser light at a satellite fitted with special light reflectors. Astronomers use the time it takes for the pulses to bounce off the satellite and return which can be milliseconds to help measure variations of sea level.
Observatory director Dr George Nicolson says Moblas-6 means that “we can take high precision measurements of the Earth’s surface along the Rift Valley that cuts vertically through the continent, for instance, to see what possibility there is that the continent will start to split apart in geological ages to come, as some scientists are suggesting”.
The South African government pays the operating costs of the facility which falls under the National Research Foundation while Nasa provides technical training and equipment. Moblas-6 is a model of international collaboration that puts aside the begging bowl, according to Rob Adam, the Director General of the Department of Arts, Culture, Science and Technology.
“At the periphery of global knowledge, we provide a critical mass of data-gathering that works for the rest of the world in exchange for the equipment that we have from Nasa we have plenty to offer.”
Launching Moblas-6, Minister of Arts, Culture, Science and Technology Ben Ngubane said that it would allow better forecasting of weather patterns, with commensurate implications on managing droughts and food security as well as providing resources for scientific development.
The Moblas-6 data will be combined with other research at Hartbeestpoort. Since 1986 the observatory has been using “very long baseline interferometry” a technology that uses radio waves thousands of kilometres long to measure the movements of the tectonic plates.
This has revealed, for example, that Africa is drifting to the north-east at a rate of 25mm a year. The observatory also has one of the four permanent global positioning satellite stations operational on the continent.