Space Science Questions and Answers – Part 5
41. Whar is light year?
As the distance between heavenly bodies is very large, the unit used to measure the distance is the distance travelled by light in one year, and is one light year.
42. What is one light year?
9.46 lakhs crores k.m.
43. What is one light second?
44. What is one light minute?
45. What is one light hour?
46. What is the distance from the earth to the moon?
15 light seconds
47. What are cosmic rays?
It is a kind of energy radiation, consisting of atomic nuclei that reach the earth from outer space
48. What are the important facttors of cosmic rays?
The important factors of cosmic rays are the nuclei of atoms of elements like Hydrogen, Helium etc.
49. What are pulsars?
Pulsars are fast rotating neutron stars. They send out radio waves in a regular frequency.
50. What is a difference between a star, satellite and a planet?
Star is a celestial body having its own light; Satellite is a secondary body that revolves round the planet. Planet is also a celestial body which revolves round the sun in elliptical orbit.