Download Galaxies Quiz – Study Guide KEY You will be given a set of images

Galaxies Quiz – Study Guide KEY
1. You will be given a set of images of galaxies. You must select which galaxy is/are:
a. Spiral
c. Elliptical
b. Spiral Barred
d. Irregular
2. Facts about our Milky Way:
a. Size (in Light Years) Diameter: ___120,000 LY___; Thickness: ___1000 LY____
b. Quantity of stars: ___200 billion__
c. Location of our Solar System (which arm?) ___ORION SPUR_ Be able to draw!
d. Distance from center of galaxy? _ABOUT 30,000 LY__
e. Type of galaxy: ___MILKY WAY IS BARRED SPIRAL___
f. Age: _10 BILLION YEARS Where are oldest stars? ____HALO____
g. Why can’t we see the center of our galaxy? OBSCURED BY DUST
h. How do we show its shape? Observations made in __INFRARED___.
i.
The Milky Way is part of the ____LOCAL GROUP (cluster of 25 galaxies).
j.
Density of stars (number per volume of space) is greatest in ___CORE__.
k. Where do we find globular clusters in the Milky Way? __HALO___
3. Facts about Galaxies:
a. Where do you find NEW stars in spiral galaxies? _______ARMS___
b. Which type of galaxy has the most NEW stars? ___IRREGULAR____
c. Which type of galaxy has the most OLD stars? __ELLIPTICAL__
d. Which type of galaxy has the most dust and gas? ___IRREGULAR__
e. Which type of galaxy is the largest (generally)? ___ELLIPTICAL__
f. Which type of galaxy is most common? __ELLIPTICAL(about 70% of all
galaxies)
g. What’s the difference between and E0 and an E7 galaxy? Draw both!
EO = CIRCULAR; E7 = OVAL (FOOTBALL)
h. What force holds galaxies together? __GRAVITY___
i.
Spiral arms are also known as ____DENSITY____waves.
4. How can we look through the dust and “see” the center of our galaxy?
Astronomers use _INFRARED and RADIO_ type of telescopes
5. “Galicos” is the Greek word for ___MILK____.
6. Hubble’s Law: The farther a galaxy is from us, the ___FASTER___ it is moving.
7. What three things make up all galaxies? Hint: Galaxy Sorting Activity.
STARS, DUST AND GAS
8. How many stars are within 10 light years of our Sun? __13___
9. What percentage of galaxies are elliptical? __70%; Spiral? _15%__ Irregular? _15%__
10. What is believed to be at the center of ALL galaxies? SUPERMASSIVE BLACK HOLE
Possible Short Answer/Essay questions:
11. How is looking at galaxies billions of light years away like looking in a time
tunnel?
THE LIGHT WE SEE HAS TRAVELED FOR THOUSANDS TO BILLIONS OF YEARS TO
REACH US, SO WE ARE SEEING WHAT THE OBJECT(S) LOOKED LIKE WHEN THE
LIGHT LEFT IT.
12. How is our Milky Way like a city? Hint: See Galaxy Video notes
THE MILKY WAY HAS PARTS THAT ARE UNDER CONSTRUCTION AS WELL AS
AREAS WHERE DEMOLITION (DESTRUCTION) HAPPENS. THERE ARE “ETHNIC”
AREAS WHERE CERTAIN TYPES OF STARS (CLUSTERS) ARE FOUND. NEBULAS
ARE LIKE THE RECYCLING CENTERS.
13. Describe two reasons why galaxies (even the same types) look different.
THEIR AGE, COMPOSITION (HOW MANY STARS, HOW MUCH DUST AND GAS), THE
PERSPECTIVE WE SEE THEM AT (ANGLE OF VIEW), THEIR DISTANCE, ETC.
14. Where is the center of the universe?
THERE IS NO CENTER. SPACE IS EXPANDING, NOT THE OBJECTS IN IT.
15. How does the Doppler Shift relate to the expanding universe?
ALL GALAXIES (NOT WITHIN OUR LOCAL GROUP) ARE MOVING AWAY FROM US
(THEIR SPECTRA IS RED-SHIFTED
16. Old galaxies are __YELLOW___ (what color?) and contain (a little or a lot) of dust.
17. Compare open and globular star clusters: Which are bigger? __GLOBULAR__Which
contain mostly young stars? _____OPEN__ Which are found in the arms of spiral
galaxies? ____OPEN In the Halo? ___GLOBULAR___
18. What is TRUE about all clusters (open AND globular)? Same ____AGE__; All rotate
around __CENTER OF GALAXY____.
19. In our Milky Way, where do we see the most star formation? __in spiral arms__
Miscellaneous and/or possible bonus questions:
20. When the Milky Way and Andromeda eventually merge, they will form a(n)
___ELLIPTICAL____ type of galaxy.
21. How old is the universe believed to be? 13.7 BILLION YEARS
22. How OLD is the Milky Way? ___10 BILLION YRS_ ; MAY 2 ON COSMIC CALENDAR
How old is our solar system? __4.5 BILLION YEARS___AUGUST 31 ON COSMIC CAL.
23. Name the two galaxies found about 170,000 light years from the Milky Way.
Hint: Both share a common name of the first person to sail around the world.
LARGE AND SMALL MAGELLANIC CLOUDS (ONLY VISIBLE IN S. HEMISPHERE)
24. How far away is the Andromeda galaxy? ___2.3 MILLION___ light years
25. How many galaxies are there in the Universe? (we think) ____50-100 billion_____
26. Why are the Hubble Space Telescope’s images stair-stepped looking?
THERE ARE FOUR CAMERAS IN ONE IMAGE
27. How did Hubble use the Doppler shift to claim the universe is expanding?
He saw that all distant galaxies were moving AWAY from us (were red-shifted)
28. Edwin Hubble first called galaxies “ ISLAND UNIVERSES”
29. Why is the sky blue? Why is the setting sun red?
Blue is most easily scattered (reflected).
Dust in the atmosphere absorbs blue and reflects red light.
30. What evidence is there for a black hole at the center of most galaxies?
The motions of stars around the center suggest something massive