Agenda Turn in Displacement Lab work Turn in Permission slips Notes on Studying Space amp Exploring Space packet Studying space from Earth Tele distance Scopos to watch Light and radiation energy in the form of waves that travel through empty space ID: 675963
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Slide1
Tuesday September 8, 2015Agenda
Turn in Displacement Lab work
Turn in Permission slips
Notes on
Studying Space &
Exploring
Space packetSlide2
Studying space from EarthTele
= distance
Scopos
= to watch
Light and radiation (energy in the form of waves that travel through empty space)
How astronomers gather info about spaceSlide3
Light
Visible light is a form of electromagnetic radiation.
Examples of electromagnetic radiation that you can’t see are radio waves and x-ray. Scientists have developed instruments that can detect these types.
Astronomers determine the size, distance and movement of space objects by studying its radiation.Slide4
Spectrum
White light separated into a range of colors is called a
spectrum
.
In a spectrum, the colors of visible light appear in the order of their
wavelengths
.
Wavelength is the distance between one wave peak and the next wave peak. Red light has the longest wavelength and purple the shortest.
Visible light is a small fraction of the Electromagnetic SpectrumSlide5Slide6
Telescopes
A telescope is a device that gathers electromagnetic radiation (light).
Telescopes provide images that are much clearer than what is seen with the naked eye because telescopes show radiation that eyes can’t detect.
Most telescopes gather radiation with a glass lens or a reflecting surface such as a mirror. Larger lenses and reflecting surfaces produce brighter and more detailed images. Slide7
Visible-light Telescopes
Reflecting Telescope – This type of telescope has
curved
mirrors
that
gather and reflect
light. The image comes into focus in front of the mirror. Many reflecting telescopes have a second mirror that reflects the image to recording equipment or to a lens called an eyepiece.
Remember: Reflecting because mirrors reflect an image!Slide8
Eyepiece
Primary mirror
Secondary mirror
L
ight
Reflecting TelescopeSlide9
Visible-light Telescopes
2. Refracting Telescope – This type of telescope has an objective lens, or curved piece of glass, at one end of a long tube. The lens gathers light and focuses it to form an image near the other end of the tube. An eye piece magnifies this image.
Remember: Refracting because the curved lens changes, bends or deflects light! Slide10
Objective lens
EyepieceSlide11
Most powerful visible light telescopes are built on mountain tops or in rural areas to avoid city lights.The atmosphere interferes with light coming in from space. The movement of the air in the atmosphere is what makes stars seem to twinkleSlide12
European Southern Observatory
Chile
Griffith Observatory
Los Angeles
Mauna Kea Observatory
HawaiiSlide13
Radio Telescopes
Radio telescopes show where radio waves are being emitted by objects in space. Radio telescopes have a large, curved metal surface called a dish. (Parabola)
They are often found in groups with all dishes aimed the same way to gather waves to improve the quality of the image.
Because radio waves are so large they can penetrate the Earth’s atmosphere. What does this mean?Slide14Slide15Slide16
Space TelescopesThe Hubble telescope is a
reflecting telescope
that was placed into orbit in 1990.
Because it’s in space, the
atmosphere
does not interfere with imaging.
The lack of atmospheric interference allows the Hubble to produce very clear images.
Atmosphere
blocks most x-rays and gamma raysSlide17Slide18Slide19
Closure
In ISN Answer:
What is radiation?
How are visible light, radio waves, and other forms of electromagnetic radiation different from each other?
What function do mirrors serve in reflecting telescopes?
Why are some telescopes placed high on mountains or in orbit around Earth?