Infrared image of Saturn
Saturn with a methane filter
1. Above are two images of Saturn taken by Craig Kulesa at the
Mt. Bigelow 1.5-meter telescope in infrared light. The image on the
left is a normal broad-color infrared image of Saturn. The image on
the right was taken with a narrow-filter that looks at wavelengths where
methane features can be present. By looking at these images, and
knowing that Saturn glows by the reflection of sunlight (at these
wavelengths), you could deduce that:
- Craig stole Saturn. Make him put it back!
- Saturn's atmosphere contains a sizeable amount of gaseous methane, and
the rings do not.
- Saturn's atmosphere contains no gaseous methane, but the rings do.
- It is not possible to determine whether Saturn or its rings
contain methane by looking at these two images.
2. If you look outside at night, you see white/yellow, red and
blue stars -- but no "green" stars. This is because:
- There are no green emission lines in stars
- The blackbody spectrum of a star is very narrow and never
encompasses any green light.
- The blackbody spectrum of a star is very broad and therefore
never encompasses only green light.
- The outermost layer of a star preferentially absorbs all green light.
3. Visible light comprises how much of the total electromagnetic
spectrum?
- All of it
- Most of it
- A small portion of it
- A negligible portion of it
4. Order the following three portions of the electromagnetic
spectrum in order of increasing energy:
- ultraviolet, visible, infrared
- infrared, visible, ultraviolet
- visible, ultraviolet, infrared
- visible, infrared, ultraviolet
5. Which scenario below might result in an emission-line
spectrum in visible light?
- You observe a star, but there's a cloud of cold gas between you
and the star
- You observe a cloud of gas in the proximity of a very hot,
luminous star
- You observe a cloud of cold gas, with no nearby hot stars.
- You observe an ordinary incandescent light bulb.
6. Which scenario below might best result in an absorption-line
spectrum in visible light?
- You observe a star, but there's a cloud of cold gas between you
and the star
- You observe a cloud of gas in the proximity of a very hot,
luminous star
- You observe a dark cloud of cold gas, with no nearby hot stars.
- You observe an ordinary incandescent light bulb.
7. The primary function of an astronomical telescope is to:
- Magnify an image of an astronomical object
- Disperse the light from an astronomical object
- Polarize the light from an astronomical object
- Collect and focus light from an astronomical object
8. The maximum resolution of a particular astronomical
telescope is defined as:
- The faintest that telescope can "see"
- The maximum size of the primary mirror or lens
- The finest detail that can be observed with that telescope
- The highest magnification achievable with that telescope
9. What severely limits the effective resolution of a large
telescope on the surface of the Earth?
- Light pollution
- Atmospheric turbulence
- The shaking of the telescope
- The resolution of the instrument (camera, CCD, etc.) collecting the light
10. What methods are used to improve the resolution of
astronomical images?
- Send telescopes into space
- Adaptive optics on ground-based telescopes
- Optical and radio interferometry
- All of the above
11. The Space Shuttle orbits the Earth at a typical speed of
17,000 mph. What minimum speed would we have to achieve to
allow the Space
Shuttle to escape the Earth's gravity (to send it to the Moon, for
example)?
- 13,000 mph
- 24,000 mph
- 34,000 mph
- 68,000 mph
12. Suppose you weigh 150 lb on Earth. If you moved to a planet
with twice the mass AND twice the diameter, what would be your new weight?
- 75 lb
- 150 lb
- 225 lb
- 300 lb
13. If you replaced the Sun with a black hole of identical mass,
what would happen to the orbit of the Earth?
- The Earth would spiral into the black hole. [Munch] [Burrrrp...]
- The Earth's orbit would stop.
- The Earth would be ejected from the Solar System.
- The Earth's orbit would be unchanged.
Craig Kulesa
Last modified: Wed Feb 10 16:17:24 MST 1999