Question

How is our atmosphere different from the atmospheres on Venus and Mars?

Answer 1

Hint: The word atmosphere comes from Greek words ‘atmos’ and ‘sphaira’ meaning ‘vapour’ and ‘ball’ respectively. The atmosphere refers to the layers of gas surrounding a planet. The earth’s atmosphere is commonly called ‘air’.

Complete answer:
Every planet has a different atmosphere. The formation of the atmosphere depends on the formation of the planet itself and its density. The differences between the atmospheres of Earth, Venus and Mars are as follows;

VENUS	EARTH	MARS
The height of the atmosphere on Venus is around 250 kilometers.	The thickness of the atmosphere on Earth is 120 kilometers.	The thickness of Mars’ atmosphere is 230 kilometers.
It is very dense as compared to that of earth and it has an extremely high temperature due to greenhouse effects and its proximity to the sun.	The earth’s atmosphere is very dense and it is more than 14 times the pressure exerted by the atmospheres of Mars.	Its density is also very low, unlike Venus and it exerts very low pressure on the surface of the planet.
It is mainly composed of Carbon Dioxide (96.5%). The next major gas is nitrogen, taking up 3.5% of the atmosphere.	It is primarily composed of Nitrogen (78%). It is followed by Oxygen which makes up 20.9% of our atmosphere.	It is also majorly composed of Carbon Dioxide, 95% to be precise. After CO2, Nitrogen is the most prominent gas (2.8%)
The total mass of the atmosphere on Venus is $4.8\times 10^{20}kg$	The total mass of the earth’s atmosphere is $5.15\times 10^{18}kg$.	The total mass of Mars’ atmosphere is around $2.5\times 10^{16}kg$.

Thus, the type of atmosphere present on Earth is the only one that is suitable for supporting life. Such an atmosphere has not yet been discovered on any other planet and is unique to Earth.

Note: Venus has a size and shape that is very similar to earth. Their volume, density and mass are also very similar. It is believed that both these planets shared a common origin process when it was formed 4.5 billion years ago. Hence, we refer to Venus as a twin or a sister planet to Earth.