Question

Which among the following is known as the red planet?
(a). Mars
(b). Earth
(c). Mercury
(d). Venus

Answer 1

- Hint: If any mineral is found on the surface of a planet and the color of that mineral is red then that planet looks like a red planet. Iron oxide gives a reddish appearance. Also iron oxide is found on the surface of mars.

Complete step-by-step solution -

Mars contains Iron oxide on its surface which gives a reddish appearance. And this is visible to the naked eye. So a mars is known as a red planet as its color looks like red due to iron oxide.
The color of water is blue from the sky and water covers about 71 percent of Earth’s surface. Hence, Earth looks like blue marble from space. Iron is available in the Earth’s crust but not on its surface. There is soil on the Earth’s surface. Hence, Earth cannot be known as a red planet as it does not appear as red from space.

Additional information
Mars is the fourth planet from the Sun and the second smallest planet in the solar system.
Earth is the third planet from the Sun.
Mercury is the smallest planet in the solar system. It is brightest as seen from the Earth when it is at a full phase.
Venus is the second planet from the Sun. It is the second brightest natural object in the night sky after the moon.

Note: Students can confuse between Earth and Mars because both planets have Iron Oxide. But Iron oxide is spread over the surface of mars and Earth has Iron in its crust.