Astronomy involves far more than just looking at stars. Comets, planets and stars, as well as collections of stars such as globular clusters (up to 1 million stars) and galaxies (up to 100 million stars) are studied. Astronomy is also concerned with how and when the universe began (the Big Bang theory being one explanation) and what will happen to it in the future. Astronomers research the nature, origin and evolution of astronomical objects to obtain a deeper understanding of the laws of physics. They are essentially physicists who use the universe as a laboratory. 

Because one cannot travel to the stars in order to retrieve pieces of them for analysis in one’s laboratory, one must use all other available information, such as radiation across the entire electromagnetic spectrum - from radio waves to gamma rays and cosmic rays - tiny particles that interact with the earth’s atmosphere or magnetic field.

Astronomers use their knowledge of mathematics and physics to study the nature, origin and evolution of astronomical objects to obtain a deeper understanding of the universe. This knowledge can be applied to developing navigational systems that will enable us to find our way through space.

Information on astronomical objects is collected by detecting their signals through space-based, ground-based, optical, gamma ray, X-ray and radio telescopes in conjunction with sensitive detecting devices. This data is analysed, often with the aid of computers, and interpreted in the framework of mathematical models incorporating the ideas of modern physics.

Astronomers do not usually work at night and sleep during the day. Many theoretical astronomers work normal hours and do not have to make any observations. Radio observations can be made during the day as well as at night, but much of the telescope’s functions are pre-programmed and do not require the constant presence of an astronomer.

Optical and infrared astronomers do the observational part of their work at night. For every week-long “observing run” at night, an astronomer will spend six to ten weeks on a normal daytime schedule, analysing data and doing other work.

Observational astronomy occupies much less of the astronomer’s time than analysing data. Observational astronomers plan research which involves the measurement of electromagnetic radiation (such as light waves). They analyse the results obtained and publish the findings so that others in the field will have access to the information.

Theoretical astronomers concentrate on developing theories concerning various aspects of the universe. It is possible to work in both theoretical and observational astronomy, although most astronomers tend to be more active in one or the other. Some astronomers also teach Mathematics or Physics at a university.


  • SA Astronomical Observatory

  • Hartebeeshoek Radio Astronomy Observatory

  • universities

Job opportunities are limited, but astronomers can usually obtain research grants anywhere in the world. Although they are not always employed in astronomy itself, astronomers are seldom unemployed, because of their high level of training in Physics.

Although astronomers cannot earn their own money directly as an astronomer, there are some who become free-lance astronomy or general science writers, or even science-fiction writers.

Getting Started

  • arrange an interview with an instructor of astronomy at a university in your area

  • arrange to visit an observatory in your area

  • the South African Astronomical Observatory usually employs a few summer vacation students (typically Mathematics or Physics undergraduates) during January of each year


Botswana International University of Science and Technology, Nelson Mandela Metropolitan University, North-West University, University of Johannesburg, University of Stellenbosch, University of the Free State, University of the Witwatersrand


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