What is Solar System? The Sun,
the planets around the Sun and the satellites around the planets are jointly
called the Solar System.
The Planets in the solar system move in a regulated path
why? Because of the gravitational force of
attraction of the Sun.
What is the diameter of the Sun?
1392000 k.m.
The average distance from the Earth to the Sun (a)
147097000 k.m. when the Sun is nearest to the Earth. (b)
152099000 k.m. when the sun is at the longest distance from the Earth.
What is the weight of the Sun?
33 lakhs times more than that of the Earth.
The gravitational force of the
Sun; 28 times more than that of
the Earth.
Time taken by the Sun for one rotation on its axis 25.4
days. (at the Equator) 33 days (near the poles)
The diameter of the Sun's orbit:
60000 light years.
The outermost layer in the
Sun: Corona. Corona changes
its shape according to the speed of motion of the Sun.
The innermost layer in the
Sun: Photosphere.
The region in between the corona and photosphere:
Chromosphere.
Why is the Chromosphere called
so? Because of the reddish colour.
The main components of
Photosphere: Hydrogen (71%),
Helium (26.5%), and other elements (2.5%).
What is Photosphere? It is the
region of the Sun where energy formation takes place.
What is cosmic year? The
revolution of the Solar system around the centre of the Milky way is called
cosmic year. Time taken for one revolution is 250 million years.
What is Chromosphere? The layer
around the Photosphere is Chromosphere.
What are Sun spots? The black
dots appearing on the Sun.
What is the temperature at the core of the Sun, where thermonuclear
reaction takes place? Around 15
million K.
The mass of the Sun: The mass is
332946 times as much as that of the Earth. (1.958 * 10(power)27 tons)
What is Solar Eclipse? When the
Sun, the Earth and the Moon come in a straight line with the Moon in the
middle, the people of Earth will not be able to see the Sun clearly for a
short time. It is called the Solar Eclipse.
What is the duration of Solar
Eclipse? 7m. 31 seconds.
When was the largest Sun spot detected? What is its
size? The largest Sun spot was
detected on 8th April 1974. It covered an area of 7000 million sq.
miles.
What is Aurora? A strange
brightness appearing occasionally in polar regions.
Height of the smallest and largest
Aurora: Largest 1000 k.m.,
smallest 72.5 k.m.
Which are the two Auroras?
Aurora Borealis in the North Polar region and Aurora Australis in the South
Polar region.
What are planets? Planets are
(including Earth) heavenly bodies within the Solar System, which
revolve round the Sun in definite orbits.
How many planets are there?
Nine.
Which are they? Mercury, Venus,
Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto
The largest planet in the Solar
System: Jupiter (Diameter 143000
k.m.)
Difference between a star and a
planet: Stars give off heat and
light whereas planets do not.
