7. Like Earth, most of the smaller planets in our Solar
System have a solid surface made of rock. However,
Jupiter, Saturn, Uranus and Neptune, the four
biggest planets, are made of gases!
Q. Is there life on other
planets?
A. All of the planets in the
Solar System have been
explored with telescopes and
space probes. So far, nothing
living has been found.
Q. What shape are planets?
A. A planet may look
round, but it is actually
shaped like a spheroid. This
means that it looks like a
squashed ball. Saturn and
Jupiter spin very quickly, so
they are the most squashed-
8. Q. Why does the Moon seem to change shape?
Q. What is an eclipse of the Sun? A. The Sun’s light only falls on one side of the
A. This is when the Moon is directly between Moon. It takes 27.3 days or one lunar month, for
Earth and the Sun. For a few moments, the the Moon to orbit Earth. As the Moon orbits
Sun’s light is blocked and the Moon casts a Earth, we see different amounts of the sunlit side
shadow onto Earth, turning day into night! of the Moon. When we can see all of the sunlit
side, there is a full moon.
An Eclipse of the Sun
Phases of the Moon
12. The Ancient Greeks were the first scientific astronomers. They worked out
the size of Earth and that there were enormous distances between our Sun
and other stars.
Reflector Telescope
Galileo Galilei
