Page 9 - My FlipBook

Tania asked, "Is Mars another planet like
Earth? Are all these planets just like Earth?"

Mama replied "No they are all quite different.
The 4 planets closest to the Sun have an outer
crust of solid rock. Jupiter and Saturn are

huge balls of gas. Uranus and Neptune are made
of ice and other frozen material."

"I see. So only the first 4 planets are like
Earth."

"No. Mercury, for example, is a lot smaller
than Earth. Mercury spins very slowly and
orbits the Sun very fast. So for a person on
Mercury in the time between sunrise and sunset
and then sunrise again, Mercury would have

gone twice around the Sun."

"So if we call the amount of time a planet
takes to go around the Sun a year on that
planet, then on Mercury a day is 2 years long.

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