Telescopes

Thinking Questions

Telescopes Quiz

What type of telescope did Galileo use?
1: Galileo used a Cassegrain telescope. 2: Galileo used the first radio telescope. 3: Galileo used the first reflector telescope. 4: Galileo used a refractor. ANSWER: Click here for the correct answer.

Many photos of the Moon, such as figure 6.2 in your text, are upside down compared to normal sight. Why?
1: Most astronomical telescopes invert images. 2: It is because of a strange printing convention of publishers since the 1700's. 3: All images are oriented to the north. 4: Most old telescopes were so constructed that they required the observer to look through them at an odd angle, making the image appear upside down. ANSWER: Click here for the correct answer.

What does it mean to say that a telescope has "one hundred power magnification" (100X)?
1: It means that observed objects appear 100 times closer. 2: It means that observed objects appears 100 times larger in dimension. 3: It means that observed objects appear 100 times brighter. 4: It means that observed objects appear 100 times closer and 100 times larger in dimension. Thus #1 and #2 above are correct. ANSWER: Click here for the correct answer.

The largest single optical telescopes in the world are of what kind?
1: refractors 2: reflectors. 3: radio telescopes. 4: It depends on what you mean by optical. ANSWER: Click here for the correct answer.

Are all optical telescope mirrors made of glass?
1: Yes, they have to be made of glass. 2: Actually, all telescope mirrors have to be made of optical crystal. 3: No. 4: Some have been made of wire mesh. ANSWER: Click here for the correct answer.