Port Macquarie Observatory Mars Tutorial

Mars is about half the size of the Earth. It is very dry but interesting surface features hint that there may have been water on the surface in the past. The poles are covered by a mixture of frozen water (water ice) and frozen carbon dioxide (dry ice). Satellite measurements show that the north polar cap is up to 3 kilometres thick at the centre. When Mars comes close to the Earth which it does every two years or so, a small telescope or powerful binoculars will show the polar caps as small white dots.

Of great interest are features which appear to have been made by running water. Although Mars is dry today some believe that water may have existed on the surface in the distant past. The existence of surface water would increase the likelihood of life having developed on Mars and remnants of that life could exist today. Others feel that these features could have been caused by other means such as volcanic activity and that water never existed on the surface and so the development of life was less likely. A lot of work is being done on this problem but no definite answers have been found yet.

Mars is about half the size of the Earth, cold and dry. The landscape is both desolate and beautiful. During the day the sky is a pink colour while the sunsets are blue.

The atmosphere is mainly Carbon Dioxide and is very thin, less than 1% that of Earth's. Even so it supports various weather phenomena including dust storms, clouds, mist and dust devils.

Although Mars has virtually no magnetic field there is evidence that, in the past it may have had a field similar to Earth. Some rocks were magnetised by this field and retain this magnetism today. This results in localised magnetic fields in some locations called magnetic bubbles.