Name two incidents that have created a great deal of interest in the planets Mars and Jupiter, respectively.

Mars

After Venus, Mars is our closest neighbour. It seems very earth-like. There are ice-caps on its poles, drifting white clouds and raging dust storms in its atmosphere. Seasonally changing patterns occur on its red surface. There are large dark areas on its surface called maria (meaning 'seas'). It even has a twenty-four-hour day. Mars experiences summer and winter seasons, each of which lasts for almost six earth mkths. However, the planet's distance from the Sun causes these seasonal changes to be more extreme. It is tempting to think of Mars as an inhabited world. In 1877, the Italian astronomer, Schiaparelli, observed an intricate network of single and double lines crisis-crossing the bright arps of the planet Mars. He gave them the name of canali. Canali in Italian means channels or erooves. But it was promptly translated into English as 'canals'.

Jupiter

The most outstanding feature on t h s~ur face of Jupiter is the Great Ked Spot . It is a long oval area which is so huge that two earths. side by side, could be dropped through it. Sometimes it becomes pale plnk in colour and at other times a fiery orange red. For long, the Great Red Spot puzzled the astronomers. Th e Pioneer and Voyager missions to Jupiter revealed that the Red Spot is a huge cyclonic disturbance in the atmosphere. Jupiter is mainly a quick-spinning ball of gas and liquid with no solid surface. It also emits radio waves. Its composition, size and the number of moons gave rise to the idea that Jupiter is not a planet but rather a star with a "sdar system" of its own, that did not start 'burning'. It is estimated that if Jupiter,were just ten times heavier, it could have started to produce its own energy like the Sun