Transcript Topic: Telescopes

Topic: Telescopes
PSSA: 3.4.7.D/S8.A.2.2
Objective:

TLW compare optical and
nonoptical telescopes.
MI #1: Optical Telescopes
Optical telescopes collect visible
light from objects in the universe
and focus it on a focal point for
closer observation.
 A focal point is the point where
the rays of light that pass through
a lens, or that are reflected by a
mirror, converge.

MI #2: Refracting Telescopes
 Refracting
telescopes use lenses to
gather and focus light.
 There are two disadvantages of
refracting telescopes….1) they focus
different colors of light differently, so
the image is not perfectly
focused….2) if the objective lens is
too big, the image gets distorted.
MI #3: Reflecting Telescopes
Reflecting telescopes use a curved
mirror to gather and focus light.
 One advantage to reflecting
telescopes is that the mirrors can be
very large.
 Reflecting telescopes can also focus
all colors of light to the same focal
point, so the image is completely
focused.

MI #4: Nonoptical telescopes
Nonoptical telescopes study
objects in space by collecting
different wavelengths of EM
radiation.
 These telescopes may collect
radio waves, infrared, X-rays, or
gamma rays

MI # 5: Hubble Space Telescope
The Hubble Space Telescope is an optical
reflecting telescope that orbits the Earth.
 It uses a mirror that is 2.4 meters in
diameter to produce exceptionally clear
images of deep space objects.
 http://hubblesite.org/gallery/album/show/
solar_system/

So What…? Real Life Application
Telescopes
are one of the
most important tools that
astronomers use to study
the universe.