1. Halley’s comet appears once in a period of:

2. The correct sequence of planets in the descending order of their equatorial diameter is :

3. Which planet is known as the ‘Watery Planet’ ?

4. Asteroids have their orbits between the planets:

5. The distance between the Earth and the Sun (in million kms.) is :

6. Which one of the following is correct? Great Bear is a : [CDS 2008]

7. In 1610, Galileo Galilei discovered four moons of which planet?

8. A blackhole is a : [CDS 1999, 2001]

9. Stars which appear single to the naked eye but are double stars when observed by a

10. Which of the following planets is known as ‘Morning Star’?

11. Which planet of the solar system spins on its axis at the fastest rate?

12. The orbits of planets around the Sun, or of satellites around the Earth, can be :

13. To a space traveller on moon, the lunar sky during day time appears:

14. Pole Star is always seen at one point in the sky whereas other stars are not; this is

15. The outermost layer of Sun is called:

16. Which of the following is the largest of the inner planets? [IAS 1990]

17. The brightest star in the sky is:

18. Which planet looks reddish in the night sky?

19. What are Sun spots? [Railways 1994]

20. In order of their distances from the Sun, which of the following planets lie between