Earth, Mars, and Venus Flashcards
What substance makes Earth unique compared to other planets?
Water (H2O, dihydrogen monoxide, or oxidane).
What percentage of Earth’s surface is covered with water?
71%.
What proportion of Earth’s water is salt water found in oceans and seas?
About 96.5%.
In what forms does water exist on Earth?
As water vapour in the air, fresh water in lakes and rivers, ice in glaciers and polar caps, and underground in aquifers.
What percentage of the human body is composed of water?
Between 50% and 65%.
How does the atmospheric pressure on Venus compare to Earth’s?
The pressure on Venus is nine times that of Earth’s atmosphere.
What are the primary components of Venus’s atmosphere?
Thick clouds of carbon dioxide.
What is the average surface temperature on Venus?
Around 450°C.
How does the size of Mars compare to Earth?
Mars is about half the size of Earth.
How does the thickness of Mars’ atmosphere compare to Earth’s?
Mars’ atmosphere is about a hundred times thinner than Earth’s.
What happens to Mars’ polar caps during different Martian seasons?
They grow during Martian winter and shrink during Martian summer.
Is there any evidence of water on Mars?
Recent visits by robot explorers suggest there may be evidence of water under the surface of Mars, but the scientific community is still divided on this.
What are Mars’ polar caps made of?
Frozen carbon dioxide (‘dry ice’).
Why is fresh water so valuable in some places on Earth?
Because it is not equally distributed everywhere, making it economically viable to extract fresh water from salty sea water using industrial processes.
