Unisa online - Suspended between heaven and earth

Increasing awareness of science through astronomy and supporting South Africa’s bid to host the Square Kilometre Array (SKA) radio telescope were the primary objectives of a recent visit by a group of US astronomers.

National Aeronautics and Space Administration (NASA) astronomer and astronaut, Dr Jeffery Hoffman; President of the International Astronomical Union, Dr Robert Williams; and lecturer from the Department of Physics and Astronomy at Western Kentucky University, Prof Charles McGruder, began their five-city tour of South Africa when they addressed the Unisa community on 9 November 2010.

Hosted by Unisa’s College of Science, Engineering and Technology and the Department of Science and Technology, the astronomers captivated the audience with lectures on shuttle missions to repair the Hubble Space Telescope (HST), seeing the universe through the Hubble, and an overview of Africa and astronomy.

Dr Robert Williams

Prof Charles McGruder

Dr Jeffery Hoffman

Their visit was a timely one considering that Africa is bidding to host the SKA radio telescope. If Africa wins the bid, an investment of about $15 billion (± R105 billion) will be injected into the continent over 50 years. The majority of the investment will go to South Africa, as South Africa is building the Karoo Array Telescope (MeerKAT) - a world class telescope in its own right.

Dr Hoffman, who became an astronaut in 1979, was assigned to the shuttle space flight missions to repair the Hubble Telescope. This is regarded as one of the most successful telescopes ever built. Dr Hoffman was also one of the four spacewalking astronauts for the first HST servicing mission in 1993. He last flew on the Shuttle Columbia and in his five space flights, Dr Hoffman logged more than 1 211 hours in space and travelled more than 34, 6 million kilometres.

He talked the audience through a video of his HST missions, explaining the importance of the telescope, and the highlights and lowlights of the missions. He said that after the first mission, he was very excited because many believed they wouldn’t be successful. "I am quite pleased and proud of the role I played, and when I think about it, I still get a warm feeling of what it was like floating up there, above the earth."

Dr Hoffman also spoke of HST’s successor, the James Webb Space Telescope (JWST), and described it as an extraordinary undertaking, one he is hoping will work and increase society’s knowledge of the universe. JWST is a planned infrared space observatory and its main scientific goal is to observe the most distant objects in the universe beyond the reach of either ground-based instruments or the Hubble. The JWST is a project of NASA, the European Space Agency and the Canadian Space Agency, and includes contributions from 15 nations.

Dr Williams said that while Dr Hoffman was busy fixing HST, he was one of the many astronomers waiting back on earth to use it for science. He took the audience on a visual journey of the science that the Hubble has produced.

The Hubble Telescope, which has seen back in time to when galaxies were first formed, has ascertained that most of the material in the universe is invisible, that the expansion of the universe is speeding up, that most galaxies have monstrous black holes and that there are more than 400 planets around other stars.

Prof McGruder said South Africa was doing a tremendous job in supporting astronomy and that this support was changing the world’s image of South Africa and Africa. He said the international community was very interested in putting telescopes in South Africa because the country is going down the right path in creating astronomers through its National Astrophysics and Space Science Programme (NASSP). He commended South Africa on the Southern African Large Telescope (SALT), the largest optical telescope in the southern hemisphere. It is located close to the town of Sutherland and is a facility of the South African Astronomical Observatory, the national optical observatory of the country.

Speaking more on the Square Kilometre Array radio telescope, he said that if South Africa beats Australia in the bid to host the telescope, it will facilitate economic development in South Africa and across Africa, will ensure scientific and technological growth, and will provide an opportunity for African astronomers and scientists to develop their skills and expertise as they will be working with the best from around the world. Additional information from www.wikipedia.org