Download Telescopes

Galileo, Galileo
• Telescopes were first invented around the year
1600.
• Galileo Galilei was an early astronomer who first
used telescopes to view objects in our solar
system.
• He made many important discoveries including:
the moon was covered in mountains and Jupiter
had 4 large moons.
Modern Telescopes
• Telescopes are instruments that collect and
focus light and other forms of electromagnetic
radiation.
• Electromagnetic radiation is the invisible
energy waves on the electromagnetic spectrum.
• A telescope that uses lenses and mirrors to
collect and focus visible light is called an optical
telescope.
• The two main types of optical telescopes are
refracting telescopes and reflecting telescopes.
Electromagnetic Spectrum
Refracting vs. Reflecting telescopes
REFRACTING
REFLECTING
• A refracting telescope, or
refractor, is a telescope that
uses glass lenses to collect
and focus light into an
image
• A reflecting telescope, or
reflector, uses mirrors
instead of glass lenses.
• These glass lenses bends
light rays to focus them.
• These were the earliest type
of telescopes, used by
Galileo to study objects in
our solar system
• The mirrors bounce light
rays to focus them.
• These were developed by
Sir Isaac Newton around
1670.
• The majority of
telescopes used today are
reflectors
Radio Telescopes
• Simply put, radio telescopes are different
from reflecting or refracting telescopes in
that
• they detect radio waves instead of light
waves
Telescopes in SPACE
• Since Earth’s atmosphere blocks many
wavelengths of invisible light, astronomers
have placed telescopes in space.
• These telescopes include the Hubble Space
Telescope, the Chandra X-Ray Observatory, and
the Spitzer Space Telescope.
• These different telescopes each observe a
different wavelength on the electromagnetic
spectrum (the spectrum of all visible and
invisible light).
Which is Which?
Use your textbook to find the differences between the
following three:
Hubble Space Telescope
Chandra X-Ray Observatory
Spitzer Space Telescope