Mars is the fourth planet from the sun. In our solar system, it is the second lightest in weight, Mercury being lighter, and the third smallest, Mercury and Pluto being smaller. It has a diameter of 4,220 miles, about half the size of Earth’s diameter. Its density is about three-fifths as great as Earth’s density, and its volume is about eleven hundredths of the density of Earth’s. An object on Mars weighs only about two third’s as much as it would on Earth. It is said that a day on Mars lasts about half an hour longer than a day on Earth, and a Martian year lasts about ten months longer than an Earth year.
The distance from Mars to the sun varies greatly during the course of its revolution, from 129 million miles at the least, to 155 million miles at the most. The distance from Mars to Earth varies from 34 million miles at the least to 250 million miles at the most.
Scientists are under the impression that Mars is the most likely planet in our solar system on which life might have evolved, although they no longer believe, as they once did, that complex or intelligent beings might live there.
Initially, in the year l969, U. S. scientists sent two unmanned spacecraft. Mariner 6 and Marina 7, to the vicinity of Mars. Photographs were radioed back from an alitude of about 2,200 miles above Mars, revealing that the surface is covered with numerous deep craters, similar to those on the moon.
In the year 1976, U. S. scientists sent two more unmanned spacecraft, Viking l and Viking 2 to the Martian surface. This time, photographs showed a reddish, rocky desert with windswept sand dunes and a light pink sky. Martian soil was tested for the presence of life which might exist, notwithstanding the thin Martian atmosphere and despite the fact that the temperature on Mars can vary during a single day from about 100 degrees below zero Fahrenheit at night, to over 70 degrees above zero Farenheit in the daytime. However, no definite proof was found in this connection.
Scientists continue to delve into the mysteries of our galaxy. Gigantic strides have so far been made in the way of discovering many facts about Mars, since the camera of the Viking I Lander had initially photographed the surface of Mars with a light sky in the distance. More explorations are continuing and are being considered in the near future, with the help of advanced technologies. The early watchers of the skies picked certain groups of stars that seemed to be together in the sky, five of which can be seen with the naked eye, the planet Mars being one of those.