Grade 9 Science: Guide to Telescope Parts and Mechanics

Grade 9 Science Telescope Parts Flashcards

What is the objective lens?

The large lens at the front of a refracting telescope. It collects light and focuses it to form an image.

What is the primary mirror?

The large curved mirror in a reflecting telescope that collects and focuses light.

What is the secondary mirror?

A smaller mirror that reflects the focused light from the primary mirror into the eyepiece.

What is the eyepiece?

The lens you look through. It magnifies the image formed by the objective lens or mirrors.

What is the focuser?

A mechanism that moves the eyepiece closer or farther away to make the image sharp.

What is the optical tube?

The long tube that holds the telescope's lenses or mirrors in the correct position.

What is the finder scope?

A small telescope attached to the main telescope that helps you find objects in the sky.

What is the mount?

The part that supports the telescope and allows it to move smoothly.

What is the tripod?

The three-legged stand that keeps the telescope stable.

What does the aperture mean?

The diameter of the main lens or mirror. A larger aperture collects more light and shows fainter objects.

What is the focal length?

The distance light travels from the objective lens or mirror to the point where it comes into focus.

What determines a telescope's magnification?

Magnification = Focal length of the telescope ÷ Focal length of the eyepiece

Which telescope uses lenses?

A refracting telescope.

Which telescope uses mirrors?

A reflecting telescope.

Why are most large telescopes reflecting telescopes?

Mirrors are easier to make large, cheaper, and don't produce color distortion