Observing Space: Telescopes
Q1. What is a telescope?
A. An instrument that collects and magnifies light or other electromagnetic radiation from distant objects.
Q2. Who invented the first telescope?
A. Hans Lippershey in 1608.
Q3. Who first used the telescope for astronomical observations?
A. Galileo Galilei in 1609.
Q4. What are the main types of optical telescopes?
A. Refracting telescopes and Reflecting telescopes.
Q5. What is a refracting telescope?
A. A telescope that uses lenses to bend light and form an image.
Q6. What is a reflecting telescope?
A. A telescope that uses mirrors to collect and focus light.
Q7. Name the largest optical telescope in the world.
A. Gran Telescopio Canarias, Spain.
Q8. What is the function of the objective lens or mirror?
A. To gather light from a distant object and form an image.
Q9. What is the function of the eyepiece in a telescope?
A. To magnify the image formed by the objective lens or mirror.
Q10. What is magnifying power of a telescope?
A. The ratio of the angular size of the image to the angular size of the object as seen with the naked eye.
Q11. Give the formula for magnifying power of a telescope.
A. M = Fo / Fe (Fo = focal length of objective, Fe = focal length of eyepiece).
Q12. What is the advantage of reflecting telescopes over refracting telescopes?
A. They avoid chromatic aberration and can be made larger.
Q13. What is chromatic aberration?
A. The failure of a lens to focus all colors to the same point.
Q14. Name one famous space telescope.
A. Hubble Space Telescope.
Q15. What is the main advantage of space telescopes?
A. They avoid atmospheric distortion and can observe in all wavelengths.
Q16. What are radio telescopes?
A. Instruments that detect radio waves from astronomical objects.
Q17. Give one example of a radio telescope.
A. FAST telescope in China.
Q18. What are infrared telescopes used for?
A. To observe cool astronomical objects that emit infrared radiation.
Q19. Name one space-based infrared telescope.
A. Spitzer Space Telescope.
Q20. What are X-ray telescopes used for?
A. To observe high-energy phenomena like black holes and supernova remnants.
Q21. Why are X-ray telescopes placed in space?
A. Because Earth's atmosphere absorbs X-rays.
Q22. What is aperture of a telescope?
A. The diameter of the main lens or mirror, which determines light-gathering power.
Q23. What is light-gathering power proportional to?
A. The square of the aperture diameter.
Q24. What is adaptive optics?
A. A technology that adjusts a telescope's optics to correct for atmospheric distortion in real time.
Q25. What is the James Webb Space Telescope designed to observe?
A. Primarily infrared light from early galaxies and stars.
Q26. What is focal length in a telescope?
A. The distance between the objective lens/mirror and the focal point.
Q27. Why are larger telescopes preferred for deep space observation?
A. They gather more light, allowing fainter objects to be seen.
Q28. What is a spectroscope attached to a telescope used for?
A. To analyze the light from celestial bodies to determine their composition and motion.
Q29. What is a binocular telescope?
A. A telescope with two optical paths for viewing with both eyes.
Q30. Why is Mauna Kea in Hawaii a preferred site for telescopes?
A. It has clear skies, low humidity, and minimal light pollution.