Sue Havel, age 10, of Salt Lake City, Utah, for her question:

What is it like on Mars?

The surface of liars is very, very bumpy and there are no seas. Breathable oxygen and drinkable water are very, very scarce and perhaps do not exist there at all. The weather is cold and in the Martian summer, even the tropics are chilly. Sometimes a few clouds form in the sky. And sometimes the winds whip howling dust storms around and around the whole planet for weeks and weeks.

For a long time, people wondered what things are like on our neighboring planet Mars. They expected it to be cooler than it is on earth because it is about 48 million miles farther from the sun. About a century ago, a famous scientist reported that he had seen a network of geometric lines on the surface. Several others saw, or thought they saw, these so called canals of Mars. A lot of people believed that they were built by intelligent Martians who lived on our neighboring planet.

Then came the space age and the clever little Mariner probes were launched to get a closer look at the surface of liars. No telescope on earth had been able to photograph those so called Martian canals and by this time most astronomers doubted they existed. But Mariner 9 sent back some clear close ups of at least one stupendous canyon along the Martian equator. It is bigger by far than any canal imagined by man.

Our own Grand Canyon here on earth seems stupendous enough. But compared with Grand Canyon on Mars, it is merely a small ditch. Suppose we could transport the mighty Martian Canyon to North America. It would reach all the way from New York to Los An¬geles. In some places the mighty cleft across the continent would be three miles deep and 75 miles wide.

Mariner 9 also sent pictures of numerous valleys. Some of these looked like the courses of mighty rivers, but astronomers are not sure that they were carved by running water. There are lowlands and high tablelands and everywhere the surface of Mars is spotted with large and small craters, somewhat like those on the moon.

lie also have some close ups of mighty Martian mountains. One volcano is twice as massive as any volcano on the earth. Its base is 310 miles wide and its steep sides rise up to a crater that is 40, miles wide. Another volcanic crater is 56 miles wide.

Another remarkable feature is a sandy dune field, 80 miles long and 40 miles wide.

The Martian day is about the same length as ours but the year is almost twice as long. The winter season crusts the polar regions with some sort of icy material and possibly the spring brings forth some sort of vegetation. True, there is shortage of water and oxygen. But the ups and downs on the Martian landscape are absolutely stupendous.  The two Viking spacecraft that landed on Mars gave us new views of the reddish surface of Mars.  The rover crafts provided us with breathtaking vistas of the expansive rocky terrain, it’s cratered surface and even some indication that there is some bit of frozen water hidden below its surface. The exploration of Mars will continue in the future.  Go to the Jet Propulsion Laboratory web site in the Science News menu for more information.