Question

Why is Venus called Earth’s “sister planet” ?

Answer 1

Hint: In order to solve this question, we should know that both Earth and Venus are planets of our solar system, and Here we will discuss about some fundamental properties of both planets Earth and Venus and then figure out about the term “sister planet” to Venus for earth.

Complete answer:
 In our solar system, Venus is the second planet from the sun after mercury and Earth is third one. So, Earth and Venus are two neighbouring planets which make many fundamental properties quite the same and for the same reason Venus is referred to as Earth’s sister planet.
Let us see some properties which are quite the same between these two planets Earth and Venus.
Planet Venus and Planet earth have almost the same size. The radius of earth is close to $R_{Earth}=6371Km$ and the radius of planet Venus is close to $R_{Venus}=6051.8Km$ which is quite the same to planet earth.
Venus and Earth have almost the same mass. The mass of planet earth is close to $M_{Earth}=5.97\times {10}^{24}Kg$ and mass of planet Venus is close to $M_{Venus}=4.86\times {10}^{24}Kg$ which is quite same to planet earth.
Venus and Earth are the neighbouring planets and their composition is also quite same.
For those similar reasons, Venus is also called Earth's “sister planet”.

Note: It should be remembered that, instead of having some similarity in planets Earth and Venus, they are also different in many aspects such as the atmosphere of planet Venus is almost $100$ times thicker than the Earth’s atmosphere.