1. [Updated]Would a nebula look colorful if you traveled into it?
2. [Updated]How do we really know what the Milky Way looks like?
3. [Updated]What would the Milky Way look like from outside?
4. [Updated]Which galaxies are closest to the Milky Way?
5. [Updated]Who discovered that the Milky Way rotates?
6. [Updated]In what direction does the Milky Way rotate?
7. [Updated]If the Milky Way were the size of a penny, how big would the rest of the universe be?
8. [Updated]Do all galaxies have names?
9. [Updated]Do magnetic fields exist throughout space?
10. [Updated]Are the spaces between galaxies filled with stars or gas?
11. [Updated]When will the next galaxy hit the Milky Way?
12. [Updated]Who discovered the first galaxy?
13. [Updated]What is the farthest object we know about in the universe?
14. [Updated]What is a quasar?
15. [Updated]Would the center of the Milky Way be hostile to Earth-like planets?
16. [Updated]What is the Great Attractor?
17. [Updated]Do galaxies evolve?
18. [Updated]What is a gamma ray burst?
19. [Updated]What cosmic explosion lit up Earth in 1998?
20. [Updated]Exactly how far from the center of the Milky Way is the Sun?
21. Is there a black hole at the center of the Milky Way?
22. How many spiral arms does the Milky Way have?
23. What is a galaxy?
24. If the Milky Way were the size of a coffee cup, how big would the rest of the universe be?

---

25. Does the Milky Way move in space or does it just stay put?
26. Do all stars belong to galaxies?
27. What is the nearest nebula to the Earth?
28. What is the diameter of the giant elliptical galaxy Messier 87 in Virgo?
29. Why are there barred spiral galaxies?
30. What is the Great Wall?
31. How many galaxies are there?
32. What is the Milky Way made of?
33. If the universe were the size of the Earth, how big would the Milky Way be?
34. Is our Milky Way flat?
35. Why do we call our galaxy the Milky Way and not something more technical?
36. What would a trip to the center of the Milky Way be like?
37. Are there galaxies that do not belong to clusters?
38. If the Milky Way were 1 meter across, how big would the rest of the universe be?
39. Are there atoms and molecules in other galaxies?
40. What is inside the nucleus of a galaxy?
41. Could quasars be powered by anti-matter?
42. What fraction of the stars in our galaxy are red giants, white dwarfs etc?
43. Why aren't there anti-matter galaxies out there in space?
44. What is 'space dust'?
45. What gives galaxies their different shapes?

1. [Updated]Are the properties inside 'Local Bubbles' the same everywhere?
2. [Updated]What is dark matter made of?
3. [Updated]What is the youngest galaxy that astronomers have seen so far?
4. [Updated]What happens when galaxies collide?
5. [Updated]How often does the Sun pass through the spiral arm it was born in?
6. [Updated]Do magnetic fields exist throughout space?
7. [Updated]What is the 'anti-matter fountain' all about?
8. [Updated]How did galaxies form from a smooth expanding big bang?
9. Exactly how many stars are there in the Milky Way?

---

10. Are there any more big galaxies hidden behind the Milky Way in our Local Group?
11. Where can I find a 3-D map of the Milky Way?
12. How can amino acids such as Glycine exist under the harsh conditions of interstellar space?
13. If all galaxies have black holes in their cores, why do some of them emit streams of particles in 'jets'?
14. What does the Milky Way look like at other wavelengths than optical light?
15. What do we know about the 'Great Annihilator' in the center of the Milky Way?
16. Where can I get a 3-D map of the universe showing the nearest galaxies and clusters?
17. If quasars are more distant than galaxies, how can their host galaxies still be host galaxies?
18. Have molecules been found in space?
19. Why are some galaxies pinwheel-shaped and others not?
20. What fraction of hydrogen in the interstellar medium is atomic, ionized or molecular?
21. How long have quasars been around?
22. Exactly how do astronomers estimate that there are 200 to 500 billion stars in the Milky Way?
23. If you observed the Milky Way from a distant quasar, would it look like a quasar too?
24. Will we ever look so far into space that we will see baby pictures of the Milky Way?
25. How do stars in distant quasars compare to those in our Milky Way?
26. Are there atoms and molecules in other galaxies?
27. What is inside the nucleus of a galaxy?
28. Could quasars be powered by anti-matter?
29. What fraction of the stars in our galaxy are red giants, white dwarfs etc?
30. Why aren't there anti-matter galaxies out there in space?
31. If a galaxy is 10 billion light years away, with the expansion, did it take light 10 billion years to get here?
32. How bright would the center of the Milky Way be without interstellar dust?
33. What would happen if a gamma ray burst exploded near the sun?
34. What happens when two galaxies collide?
35. What chemicals have been detected in space?
36. How are the distances to galaxies measured?
37. Is our Milky Way as old as some of the proto-galaxies seen in the Hubble Deep Field photograph?

1. Where do the jets in active galactic nuclei come from?
2. What is the Lyman Alpha Forest?
3. In the expanding universe, space is said to be expanding while at the same time galaxies are not moving. Isn't this a contradiction?
4. How do astronomers measure the distances to far away galaxies?
5. What are spiral density waves made of?
6. Could galactic dark matter be black holes that formed before the Era of Nucleosynthesis?
7. What is it that triggers a spiral density wave in a galaxy in the first place?
8. How does a spiral galaxy avoid wrapping itself up into a big knot of stars?
9. How do astronomers know that the sun is located 50 parsecs above the plane of the Milky Way?

RETURN to the Question and Answer Index.