Is there life on other planets?

The man from Mars

We know that other planets also have days and nights and seasons. One of the questions that has always proved fascinating to almost everybody is whether there are creatures on any of these other worlds to see these changes. The "man from Mars" has become one of the most popular subjects for jokes. Why Mars? We naturally expect that if life exists on other planets it would be on those most like the earth. These are Mars and Venus, the two planets nearest to us. Venus is toward the sun and Mars is in the other direction.
Of the two, the nearest planet Venus is more like the earth in size and distance from the sun, but Mars has been of more interest because its surface can be seen. Venus has an atmosphere that is apparently mostly carbon dioxide, heavier than that of any other planet, which effectively hides it from view.

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Mars was named for the god of war because of its red color, which is plain even to our unaided eyes. When Mars is closest to the earth and sunlight is reflected directly from it, a very modest telescope will enlarge it to the apparent size of the moon. Although we can't see its features as clearly as the moon's, we have been able to learn more about its surface than about any other object in the sky except the moon.

What are the effects of seasons on Mars?

img source. The ice caps over the pole of Mars shrinks and grows with the seasons.

The most noticeable features of Mars as seen through a telescope are the ice caps at its north and south poles. These appear just as those on earth would to a man on Mars. Since Mars is tilted at about the same angle that earth is, it has seasons as we do. The effect of the seasons can be clearly seen in the growing and shrinking of the polar ice caps. Another seasonal change has convinced most astronomers that there is some form in plant life in low-lying areas. These areas change from blue-green in summer to brown in winter. Seasonal changes also are accompanied by an effect that looks much as if water flowed into these areas of vegetation from the polar caps as they melt.

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A great argument raged among scientists for many years about these markings. Some saw straight canals connecting "oases," from which they concluded that there must be intelligent creatures on Mars who had dug the canals to irrigate their lands. Astronomers at present are very doubtful about these canals, but they do agree that it appears as if moisture, perhaps in the form of vapor, comes down from the polar caps and seems to nourish plant life. They also agree that the lighter areas, which gives Mars its red color, are desert of rusty rocks. They have not been able to detect enough oxygen in the atmosphere to support animal life as we know it, but they do find evidence that both water and oxygen was once plentiful. It is quite possible that there once were creatures on Mars, and it is conceivable that they are still there. But they would have had to find a way to produce life-giving oxygen and water from the rocks by chemical means and also a way to keep warm during the planet's sub-zero nights.