Monday, April 29, 2013

Quiz 4/29/2013

1. What does our galaxy look like?
Our galaxy consists of a flat disk with spiral arms surrounding a central bulge, with a roughly spherical halo surrounding everything.
2. How do stars orbit in our galaxy?
Disk stars orbit the galaxy's center in orderly circles that all go in the same direction, bobbing slightly up and down as they orbit. Halo stars swoop high above and below the disk on randomly oriented orbits.
3. How is gas recycled in our galaxy?
Through the star-gas-star cycle, atomic hydrogen clouds, molecular clouds, star formation, nuclear fusion in stars, returning gas, hot bubbles.
4. Where do stars tend to form in our galaxy?
Stars tend to form in the Orion Nebula.
5. Who is Andrea M. Ghez?
Andrea M. Ghez is a professor in the Department of Physics and Astronomy at UCLA. She's discovered many stars in a highly elliptical orbit around the huge black hole at the center of our galaxy.
6.What is the name of our galaxy?
The Milky Way Galaxy
7. What is the ratio between the diameter and the thickness of the galactic disc?
100000 : 1000
8. Is our galaxy rotating?
Yes, our galaxy is rotating.
9. Can our galaxy be seen at night far from cities?
Yes it can.
10. Why do we need satellites to detect gamma rays from our galaxy?
We need satellites because our ozone layer protects us from the gamma rays, making them impossible to detect.

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