Mars The Red Planet By Sam Student and Laura Learner

Mars is an inner planet of the Solar System, being the fourth planet from the Sun (which is a star). It is the seventh largest planet, considerably smaller than Earth. There are nine planets in total, plus asteroids (mini planets), comets and meteors.

All the planets revolve around the Sun. The average distance of Mars from the Sun is 227, 940,000 km. It takes the Earth 365 days (one year) to complete one revolution, but it takes Mars 687 days.

A day on Mars is nearly the same length as a day on Earth. It takes 24 hours and 37 minutes for Mars to rotate on its axis.

Mars is known as the “Red Planet”. This is because there is a large amount of iron in the soil on Mars. It is the planet which is most like Earth, but there has been no life form found on Mars.

Photographs have been taken by spacecraft of what appear to be very large dry river beds on Mars, so it is thought that there may have been flowing rivers over five billion years ago. There may still be water under the surface of Mars.

The environment on Mars would not be suitable for any Earth creature to survive. The temperature in summer on Mars would be suitable for humans as it can reach 20 degrees C during daylight, but at night in Winter the temperature can drop to -140 degrees C. The ferocious winds and dust storms would be too fierce for humans.

In 1964 it was established by the US National Academy of Sciences that life requires four conditions: - the presence of liquid water - elements needed for metabolism and reproduction (in particular carbon, oxygen, nitrogen and hydrogen) - a source of energy - suitable environmental conditions (including moderate temperatures).

The atmosphere on Mars is very different to Earth. It is made up mainly of carbon dioxide with small amounts of other gases. The air on Mars contains only about 1/1000 th as much water as Earth’s air. Gravity is also much weaker, and there is extremely strong ultra- violet radiation, which sterilises the surface of Mars, and which would destroy living creatures on Earth.

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