William HerschelWilliam Herschel

Discovery of Infrared Radiation - 1800

Build your own

Herschel demo

The full electromagnetic spectrum …The full electromagnetic spectrum …

Making Light of it All!

The Electromagnetic The Electromagnetic SpectrumSpectrum

Our eyes see only part of the electromagnetic spectrum…

Riding the WaveRiding the Wave Light is a transverse wave of electromagnetic Light is a transverse wave of electromagnetic energyenergy

The wavelength (and, reciprocally, the The wavelength (and, reciprocally, the frequency) of light defines its radiation frequency) of light defines its radiation band (X-ray, or Visible, or Infrared, or …)band (X-ray, or Visible, or Infrared, or …)

Light has a dual nature: It exhibits both wave-like and particle-like properties

FORMULA CONNECTINGWAVE & PARTICLE PROPERTIESOF EM RADIATION:

E = h c /

E = energy per photon (joules, J)h = Planck’s constantc = speed of light (m s-1) = wavelength (m)

Low-energy LightLow-energy Light

InfraredInfrared• Thought of as “heat,” common in Thought of as “heat,” common in daily livesdaily lives

MicrowavesMicrowaves• Used for communication, cookingUsed for communication, cooking

RadioRadio• Wavelengths of centimeters to Wavelengths of centimeters to kilometerskilometers

• Great for transmissions that need Great for transmissions that need to go far and penetrate buildingsto go far and penetrate buildings

High-energy LightHigh-energy Light

Gamma RaysGamma Rays• Radioactive atoms, Radioactive atoms, nuclear power plantsnuclear power plants

X-RaysX-Rays• Penetrate soft tissuePenetrate soft tissue

UltravioletUltraviolet• Tans and sunburns, Tans and sunburns, mostly stopped by mostly stopped by atmosphereatmosphere

Temperature determines theTemperature determines themain type of radiation main type of radiation

emitted …emitted …

(left to right: Compton, Chandra, Hubble, and Spitzer space observatories)

““Invisible” Light in Invisible” Light in AstronomyAstronomy

Each part of the spectrum provides a piece of the puzzle in

understanding our universe.

The Pinwheel Galaxy – M101

http://hubblesite.org/newscenter/archive/releases/2009/07

Multi-wavelength astronomyMulti-wavelength astronomy

Constellation OrionConstellation Orionleft:left: visual-wavelength view visual-wavelength view

right:right: far-infrared view far-infrared view

An object can appear radically different depending on the type of light An object can appear radically different depending on the type of light collected from it:collected from it:

Visible Near Infrared Mid-Infrared

Visible: dark nebula, heavily Visible: dark nebula, heavily obscured by interstellar dustobscured by interstellar dust

Near-IR: dust is nearly Near-IR: dust is nearly transparent, embedded proto-transparent, embedded proto-stars can be observedstars can be observed

Mid- and far-IR: glow from Mid- and far-IR: glow from cold dust is directly cold dust is directly observable observable

EARTH ATMOSPHERIC OPACITY VERSUS WAVELENGTH

There’s a problem for IR There’s a problem for IR astronomy...astronomy...

Earth’s Earth’s atmospheric water atmospheric water vapor absorbs vapor absorbs almost all almost all incoming infrared incoming infrared radiationradiation

Even mountain-top Even mountain-top observatories get observatories get a limited view of a limited view of the infrared the infrared universeuniverse

thermal-IRimage ofEarth froma weathersatellite

View of troposphere / View of troposphere / stratosphere boundary from abovestratosphere boundary from above

And a Solution...And a Solution...

High-flying High-flying aircraft --above aircraft --above 40,000 ft -- can 40,000 ft -- can observe most of observe most of the infrared the infrared universeuniverse

Airborne infrared Airborne infrared telescopes can be telescopes can be more versatile -- more versatile -- and much less and much less expensive -- expensive -- than space than space infrared infrared telescopestelescopes

NASA’s Kuiper Airborne Observatory (KAO) C-141 with a 36-inch telescope onboard, based at NASA-Ames near San Francisco, flew from 1975 - 1995

,

Further information:Further information:

SOFIA Science Center home pageSOFIA Science Center home page• http://www.sofia.usra.eduhttp://www.sofia.usra.edu

Spitzer Space Telescope’s award-winning infrared Spitzer Space Telescope’s award-winning infrared tutorialtutorial• http://coolcosmos.ipac.caltech.eduhttp://coolcosmos.ipac.caltech.edu

(includes instructions for home-made Herschel demo)(includes instructions for home-made Herschel demo)

Each part of the spectrum impacts our daily lives…

““Invisible” Light in Invisible” Light in SocietySociety

Microwave ovens

Communications

Remote controls X-rays

Sunscreen

We collect light from distant objects, and bring together researchers from

many disciplines.

The Tools of Our SearchThe Tools of Our Search

Where did we come from?

What is our destiny? Are we alone?

Our Place in the Universe

Are we alone?

Searching for Life

JUPITER – heat from formation still escaping

The Orion M42 star-forming

region(left to right: visible-,

near-IR, mid-IR)

To find the earliest galaxies, we will need to explore the universe

in the infrared.

Looking Back in Time

Active Astronomy (“AA”) classroom Active Astronomy (“AA”) classroom kitkit

Middle School physical science,Middle School physical science,High School physicsHigh School physics

• 4 activities comparing and contrasting4 activities comparing and contrastingvisual & infrared lightvisual & infrared light

• Teachers’ guide including curricular Teachers’ guide including curricular material,material,pre-/post-tests, parts list available at:pre-/post-tests, parts list available at:

www.sofia.usra.edu/Edu/materials/www.sofia.usra.edu/Edu/materials/edu_materials.htmledu_materials.html

Resources Resources SOFIA Active AstronomySOFIA Active Astronomy

http://www.sofia.usra.edu/Edu/materials/activeAstronomy/http://www.sofia.usra.edu/Edu/materials/activeAstronomy/activeAstronomy.htmlactiveAstronomy.html

Stanford Solar Center Spectrascopes and Colors of the Sun videoStanford Solar Center Spectrascopes and Colors of the Sun video

http://solar-center.stanford.eduhttp://solar-center.stanford.edu

The Dynamic SunThe Dynamic Sun

http://www.hightechscience.org/the_dynamic_sun.htmhttp://www.hightechscience.org/the_dynamic_sun.htm

Project SpectraProject Spectra

http://lasp.colorado.edu/home/education/k-12/project-spectra/http://lasp.colorado.edu/home/education/k-12/project-spectra/

Project SpectraProject Spectra

http://lasp.colorado.edu/home/education/k-http://lasp.colorado.edu/home/education/k-12/project-spectra/12/project-spectra/

Further information:Further information:

• SOFIA Science Center home pageSOFIA Science Center home page

http://www.sofia.usra.eduhttp://www.sofia.usra.edu

• Spitzer Space Telescope’s award-winningSpitzer Space Telescope’s award-winning

infrared tutorial:infrared tutorial:

http://coolcosmos.ipac.caltech.eduhttp://coolcosmos.ipac.caltech.edu• (includes instructions for home-made(includes instructions for home-made

Herschel demo)Herschel demo)