Reflecting telescope

Reflecting telescope

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Reflecting telescopes

• Remember that a refracting telescope uses a convex lens to collect light

Reflecting telescopes

• Another kind of telescope uses a mirror instead of a lens

• This kind of a telescope is known as a reflecting telescope

Concave mirrors

• The mirror used in a reflecting telescope is a concave mirror.

• A concave mirror curves inward and collects light from distant stars and bring the light to focus.

Multiple Choice

A refracting telescope uses which type of lens?

• convex lens

• concave mirror

Multiple Choice

A reflecting telescope uses which type of mirror?

• convex lens

• concave mirror

Newton's telescope

• An English scientist made the first reflecting telescope in 1671.

• He used a concave mirror to reflect light and form an image

Newton's telescope

• Newton used a convex lens as an eyepiece to magnify the image.

• He could not look at the image formed inside the telescope tube.

• His head would have blocked the incoming light so he used a flat mirror to reflect the light to one side

Multiple Choice

Who created the first reflecting telescope

• Isaac Newton

• Galileo Galilee

Multiple Choice

Who was the first person to look at the moon through a telescope?

• Isaac Newton

• Galileo Galilee

Modern reflecting telescopes

• Today's reflecting telescopes have very large mirrors.

• One of the largest reflecting telescopes is the Hale Telescope on Mt. Palomar in California

Hale telescope

• The mirror is so big that an astronomer can sit inside the telescope.

• The astronomer sits up high near where the image is formed.

• Because the mirror is so big the amount of light blocked by the astronomer is too small to affect the image.

Multiple Choice

Where is the largest telescope located?

• Maryland

• California

• Egypt

• Australia

Multiple Choice

What is the name of the largest reflecting telescope?

• The Charles

• The Hale

• The John

• The Michael

Poll

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