Stars and the solar system

Q1) what is a star

Ans: stars are large spheres made up of gases

Q2) what is the sun made up of

Ans: the sun is made up of 75% hydrogen and 25% helium.

Q3) what is a planet

 

Ans: A planet is defined as a nearly round-shaped celestial body that is in orbit around the sun. a planet has strong gravitational force.

Q4) what is the solar system comprise ?

 

Ans: the sun, eight planets, the three dwarfs planets, the moons of all the planets, asteroids and comets make up the solar system.

Q5) why is Venus a terrestrial planet?

 

Ans: venus is called terrestrial planet because it is composed primarily of rocks and metals. It therefore has relatively high density and solid surface.

Q6) what is the earth's atmosphere made up of ?

 

Ans: the earth's atmosphere is made up of 77% nitrogen, 21% oxygen and water vapour.

Q7) why is Venus called the evening star?

 

Ans: Venus is called the evening star because it reflects about 75% of the sunlight and it is one of the first objects that appear in the night sky.

Q8) what are asteroids ?

 

Ans: Asteroids are small irregular-shaped rocky bodies that are found orbiting the sun mostly between Mars and Jupiter.

Q9) what are comets?

 

Ans: Comets are balls of ice and dust that orbit the sun in highly elliptical orbits that take them to the edge of the solar system.

Q10) Name the largest planet of the solar system?

 

Ans: Jupiter

Q11) How is a blue star is different from a red star ?

 

Ans: Big young stars are very hot and shine with a blue color when a star runs out of its fuels, it becomes a red star.

Q12) why does a full moon appear completely round? 

When does it occur?

 

Ans: when we see the entire illuminated side of the moon, it appears completely. This phase is called full moon, it occurs on day 14.

Q13) how does a planet move around the sun in a definite path?

 

Ans: the orbit of a planet is determined by the sun's gravitational force, which pulls it inwards, and the centrifugal

force, which pushes it away from the sun. the region where both these forces are balanced is the path followed by the planet.

Q14) What are shooting stars? How are they formed.

 

Ans: A shooting star is a meteor traveling through the earth's atmosphere. Meteoroids are fragments resulting from the collision of two or more asteroids,That orbit the sun. Upon entering the earth's atmosphere, air friction causes the body to heat up, burn and emit light.

Q15) which planet rotates on its sides? Why?

 

Ans: Uranus is unique in that its axis of rotation is inclined at 97ْ . this means it rotates almost on its sides .

Q16) explain the phases of the moon with a diagram.

 

Ans:

New moon -Gibbous – half moon - crescent – full moon

Q17) Describe any one terrestrial and one gas planet

 

Ans: from space our planet Earth appears as a bluish globe with dense white clouds. The earth's atmosphere is made up of 71% nitrogen, 21% oxygen with traces of argon, carbon dioxide and water vapour.

Uranus is unique in that its axis of rotation is inclined at 97ْ . this means it rotates almost on its sides.

Q18) What are artificial satellites? List their uses.

 

Ans: An artificial satellite is a man made device that has been placed into orbit around the Earth or another planet.

Artificial satellites perform specific functions. They are used to study the universe, forecast weather, track cyclones, record earth quake.