Page 187 - Science Class 08

mass, Jupiter has two and half mes the gravity 49500 km. The planet’s atmosphere is mostly
of the earth. Jupiter rotates faster than any composed of hydrogen and helium. Neptune’s
other planet. One day on Jupiter is less than 10 surface gravity is a li le greater than that of
hours. A year on Jupiter equals to 11.9 Earth the earth.
Years. Jupiter has 28 moons and a thin, Pluto

transparent ring.
It was believed that Pluto is the last known
The most no ceable feature of Jupiter is the planet located near the edge of the solar
Great Red Spot. The diameter of the Great Red system. It was discovered only in 1930. Since it

Spot is more than three mes the diameter of is very far from the sun, it receives no solar
the earth. The most widely accepted theory of radia on at all. That’s why it is very cold.
the Great Red Spot is that is swirling mars of
But, scien sts have found that Pluto is actually
gas like a giant hurricane.
the moon of Neptune which has escaped into
Saturn : Saturn is the second largest planet its own orbit. Therefore, Pluto is not considered
with a diameter of 120,000 km. It has 95 mes as a planet.
the mars and 9.4 mes the diameter of the

earth. A series of rings revolve around the
planet. The rings are composed of billions of
chunks of frozen material ranging in sizes from
Out of the four giant planets with rings, only
ny marbles to nine-meter wide rings appear
Saturn’s rings can be seen from the earth.
smooth and wide. The diameter of the outer-
Scien sts have found 61 natural satellites so
most ring is 2755000 km. Saturn has 32 moons.
far.
Because it is mostly gas, Saturn is less dense
than water. The gravity of Saturn is about the
same that of the earth. If Saturn is placed in a
large ocean it will float on water.
1. Name the planets of the solar system.
Uranus : Uranus has diameter of 51800 km. It
2. Why Pluto has been considered as a
was discovered on 13 March 1781. Uranus is
dwarf planet?
considered to be a gaseous planet like Jupiter 3. What do you mean by the chromosphere
and Saturn. Uranus looks blue because of the
of the sun?
green colour of Methane in its atmosphere.
4. How does the heat of the sun reach our
Most of Uranus is composed of light gases earth?
and ice.
5. Name the outer planets.
A unique feature of Uranus is its rota onal 6. Which planet has the largest number of
posi on. Uranus is pped almost on its side. It moons?
also rotates from east to west. The length of

one day on Uranus is not known for certain. Other Objects in the Solar System
Uranus has five known moons.
Apart from the planets and their moons, there
Neptune : Neptune, the last gaseous planet, are some minor bodies in the solar system.
appears pale blue. Its diameter is about These are the asteroids, meteors and comets.

Science-8 187