The numbers
- Diameter
- 4,220mi(6,792 km)
- Gravity
- 0.38Earth gravities
- Length of a day
- 24.7hours
- Length of a year
- 687days
- Average temperature
- -85°F(-65 °C)
To get an idea
Its gravity is so weak that a child could jump about three times higher.
A Martian day lasts almost as long as ours: only half an hour more.
It has two moons, but they are tiny rocks compared with our Moon.
Fun facts
These are not in the book: there was no room on paper.
In 1877 Schiaparelli described dark lines on its surface that he called channels.
Those channels did not exist: they were an optical illusion, but for decades they fed stories about Martians.
Mars has no magnetic field to protect it, and that helped it lose its air.
Martian dust storms can cover the whole planet and last for weeks.
It is the planet where the most probes have landed: no other world has been explored like this.
Test yourself
The first question is the one printed under the QR code, with the answer the book did not give. The other four only exist here.
Question 1 of 5★ is the one from your book
Why is Mars red?
Question 2 of 5
How long is a day on Mars?
Question 3 of 5
Why can't liquid water stay on the surface of Mars?
Question 4 of 5
What are Phobos and Deimos?
Question 5 of 5
Did the channels Schiaparelli saw really exist?
Riddles
I am the color of rust because I really am covered in rust. My day lasts almost as long as yours and I have seasons like you, but almost all my air has slipped away. What am I?
I have two little pebbles circling me instead of a real moon. At my poles the ice grows and shrinks every year, and nobody has found anybody here yet. What am I?
More than any other world I have had visitors: machines that came down from the sky and roll and dig. Once, they say, I had rivers. What am I?
Try it yourself
Look at an iron object that has been left outside for a long time. That reddish coating is the same stuff that colors a whole planet.
Jump as high as you can and mark the spot on the wall. On Mars, with the same push, you would get about three times higher.
The words
- iron oxide
- Iron combined with oxygen: it is rust, and it is reddish.
Sources: Wikidata (Q111), Wikipedia (Marte (astronomia)) and NASA.