spectroscopy , its types and applications(1).ppt

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1. Prologue
•Designer: Eric Kimsey
•The following powerpoint presentation was designed
to fulfill the requirements of the TAPS program at
Jefferson Labs in Newport News, VA summer 2006.
•This presentation was also designed to accompany
and expound upon the topic of Light and the
Electromagnetic Spectrum as required by the state of
Virginia Physical Science SOL’s (PS.9c).

2. Spectroscopy
A Tool of Astronomers

3. Definitions
•Spectroscopy- the study of the light
from an object.
•Spectrometer- an instrument which
spreads out light making a spectra.
•Spectra- range of electromagnetic
energy separated by wavelength.

4. Astronomers use
spectroscopy because it
allows them to determine the
makeup of stars… without
having to be present to take
samples.

5. Studying an objects spectra can
tell scientists the composition of
an object, its temperature, its
density and its motion.

6. Two modern applications of
spectroscopy in space…

7. Mars Exploration Mission
The Mars Exploration Rovers were launched with the goal of
searching for and analyzing rock and soils on Mars. They utilized
several spectrometers to analyze samples.
Mini-TES: miniature thermal emission
spectrometer (examine rock, soil &
atmosphere)
MB: Mossbauer Spectrometer
(examine mineralogy of rocks &
soils)
APXS: Alpha Particle X-ray Spectrometer
(analyze elements in rocks & soils)

8. Cassini-Hyugen’s Mission
Mission: to gather information
on Titan (Saturn’s moon).
VIMS: Visual and Infrared
Mapping Spectrometer (gather
data about surface, rings &
atmosphere of Titan and
Saturn).
CIRS: Composite Infrared
Spectrometer (searches for
heat and by that gather
information on the object’s
composition.

9. 2 Basic Types of Spectra
•Continuous- energy of all wavelengths
•Discrete- energy at a particular
wavelength
–Emission or bright lines
–Absorption or dark lines

10. Continuous Spectrum
•Also called thermal
or blackbody
spectra
•Spectra of stars,
planets, moons
•Depends on
temperature
Ex: sunlight passing
through a prism

11. Hotter objects
Shift toward this end
Cooler objects
Shift toward this end
Shorter
wavelength
Longer
wavelength
Continuous Spectrum
continued

12. Discrete Spectrum
Absorption
Hot object
Cool,
thin gas
Spectra
Absorption
spectrum
Ex: stars,
planets w/
atmospheres,
& galaxies
Each element
has a unique
signature of
absorption
lines. That
pattern helps
scientists
identify the
element(s).

13. Discreet spectrum-
Emission
Cold,
empty
space
Spectra
Emission
spectrum
Thin,hot
gas
Again, the
pattern of the
lines
determines
the identity of
the element.
Ex: comets, nebula
& certain stars

14. Motion of Objects in Space
Blue shift shows object is
moving toward the observer.
This shows the
normal position or
no motion.
This shows a red shift
meaning that the
object is moving away
from the observer.
Compare the dark lines in the middle spectra to
the dark lines in the other two spectra.

15. Spectroscopy Lab
Determining the Spectra
of Certain Elements

17. What type of spectra
is shown here?
•Continuous
•Absorption
•Emission

18. What type of spectra
is shown here?
•Continuous
•Absorption
•Emission

19. Why does this picture represent
just the continuous spectrum of
light?

20. Light is just one portion of the
electromagnetic spectrum.
Name 5 other parts of the EM
spectrum.

21. Acknowledgements
•www.ipac.caltech.edu/Outreach/Edu/Spectra/spec.html
•www.astronomynotes.com/lights4.htm
•http://saturn.jpl.nasa.gov/spacecraft/instruments-cassini-cirs.cfm
•http://pmo-sun.uoregon.edu/~astrosites.html
•http://marsrovers.nasa.gov/overview

22. No way! Were you sleeping?
Back to question #1

23. YES, we have a winner!
To next question….

24. Pat yourself on the back!
Next question

25. That is a definite NO!
Back to 2
nd
question