Tour of the EMS Video Guide Teacher version
http://missionscience.nasa.gov/ems/emsVideo_01intro.html
Introduction: (5:03 min)
Compare EM waves and ocean waves.
Both transmit energy but EM waves travel through space; both have crests and troughs
Define: wavelength distance between wave crests
Define: frequency number of crests that pass a point in one second
How is energy related to wavelength and frequency?
The lower the frequency and the longer the wavelength the lower the energy
What can astronomers learn about an object from its electromagnetic spectral signature?
Chemical composition, temperature and density
Type of
radiation
Radio waves
Length
Visible light
Red: 700 nm
Violet: 380 nm
Chemical composition of
atmosphere, temperature of
objects, changes in Earth’s surface
Ultraviolet
400 nm to 10 nm
Young hot stars, composition of
Earth’s atmosphere, composition
of Saturn system, view shadows of
lunar craters looking for ice
19cm – diameter
Earth
What can we learn about from
using this radiation?
Stars, pulsars, giant clouds of
super heated plasma, quasars,
radio waves from sun’s corona,
Jupiter’s bursts
2 other Facts about this type of
radiation
Travels speed of light
Can’t hear it without speaker
First transmitted by Marconi in 1894
First discovered in 1888
Need giant antennas to receive weak
space signals
White light made up of rainbow
colors
Sun temperature mostly in yellow
wavelengths
Only part of EM spectrum we can see
Newton looked at light using prism
Sky is blue because N and O scatter
blue light towards us
Hotter flames are more blue than
yellow
Lasers can be used to measure
distances to objects and surface
topography
Bugs see UV light
3 types of UV: A, B, C
UVB causes sunburn
Ozone absorbs UV so most does not
reach the surface
Radio Waves: (3:39 min)
At what speed do radio waves travel?
Speed of light
What size are radio waves?
Longest: 19 cm to greater than Earth diameter
What are 3 objects in space that emit radio waves?
Stars, pulsars, giant clouds of super heated plasma, quasars, radio waves from sun’s corona, Jupiter’s bursts
How does a speaker allow us to hear radio waves in the air around us?
Vibrates the air
Visible Light: (4:50 min)
What is the range of visible light?
Red:
700 nm
Violet: 380 nm
What are two things we learn about objects based on color?
Chemical composition of atmosphere, temperature of objects, changes in Earth’s surface
How can we use light to measure distances and make maps?
Laser light time to travel out and back gives us distance because we know the speed light travels
Ultraviolet: (3:40 min)
What is the length of ultraviolet light waves?
400 nm to 10 nm UVA, UVB and UVC
What protects us from most UV radiation?
ozone layer of atmosphere
What types of information do scientists get from UV radiation?
Young hot stars, composition of Earth’s atmosphere, composition of Saturn system, view shadows of lunar craters looking for ice
Tour of the EMS Video guide
Introduction:
1.
Compare EM waves and ocean waves.
2.
Define: wavelength
3.
Define: frequency
4.
How is energy related to wavelength and frequency?
5.
What can astronomers learn about an object from its electromagnetic spectral signature?
Type of
radiation
Radio waves
Length
What can we learn from it?
2 other Facts about this type of radiation
Visible light
Ultraviolet
Tour of the EMS Video guide
Introduction:
1.
Compare EM waves and ocean waves.
2.
Define: wavelength
3.
Define: frequency
4.
How is energy related to wavelength and frequency?
5.
What can astronomers learn about an object from its electromagnetic spectral signature?
Type of
radiation
Radio waves
Visible light
Ultraviolet
Length
What can we learn from it?
2 other Facts about this type of radiation