Telescopes
Key Concepts What are the regions of the
electromagnetic spectrum? What are telescopes and how do they
work? Where are most large telescopes
located?
Telescopes - Key Terms
Telescope Electromagnetic
radiation Visible light Wavelength Spectrum Optical
telescope
Refracting telescope
Convex lens Reflecting
telescope Radio telescope Observatory
Telescope
A device that makes distant objects appear to be closer.
Galileo made the telescope famous.
He was the first to see sunspots, Saturn’s Rings, and the four large moons of Jupiter
Electromagnetic Radiation Energy that can travel through space in
the form of waves
Examples of Forms of Radiation visible light – radiation you can see infrared – feel as heat radio waves
Types of Telescopes
Instruments that collect and focus
light and other forms of electromagnetic radiation.
Optical telescope – uses lenses or mirrors to collect and focus visible lightTwo types – refracting and reflecting
Non-optical – Use other forms of electromagnetic radiation such as radio waves, x-rays and gamma rays
Refracting Telescopes Uses convex lenses to gather and focus light Convex lens is a curved piece of glass that is
thicker in the middle than the edges The larger the lens the more light the
telescope can collect Simple refracting telescope has 2
lenses – the objective lens and the eyepiece lens
Yerkes Telescope in Wisconsin is the largest refracting telescope
Reflecting Telescopes Isaac Newton built the first in 1668 Uses a curved mirror to collect and focus
light The larger the mirror, the more light that
can be collected Largest optical telescopes today are
reflecting
Radio Telescopes
Devices used to detect radio
waves from objects in space Most have curved reflecting surfaces
that focus radio waves the way the mirror does in reflecting telescopes
Concentrate the faint radio
signals onto small antennas like those on radios
Ex. The Very large Array, Arecibo
Other Telescopes
Detect: Infrared – Spitzer Space Telescope Ultraviolet X-rays – Chandra X-Ray Observatory Gamma rays
Hubble Space Telescope detects
visible, ultraviolet, and infrared