Rotating Question Curious About Astronomy? Ask an Astronomer

All previously answered questions (most recently added first)

  1. How do I maximize my chances of seeing shooting stars? (added 4th January 2013)
  2. Are exoplanets real? (added 4th January 2013)
  3. Can the Sun be closer to the Earth than any planet is to Earth? (added 27th September 2012)
  4. Cosmologists say the expansion of the universe is accelerating, what is driving this? (added 14th August 2012)
  5. If photons have zero mass, why do they feel the effects of gravity? (added 23rd April 2012)
  6. What time is sunrise/sunset or moonrise/moonset at my location? (added 30th March 2012)
  7. What causes the aurora? (added 2nd March 2012)
  8. What do all the angles in a table for a planet's orbit mean? (added 24th January 2012)
  9. How likely is it for a planet to transit its star? (added 29th December 2011)
  10. Is the Moon always visible during winter on the North Pole? (added 15th December 2011)
  11. Why is the Moon higher in the sky in winter and lower in the summer? (added 15th December 2011)
  12. Does the Moon look different in the northern and southern hemispheres? (added 12th December 2011)
  13. Why do astronomers use telescopes? (added 8th December 2011)
  14. What happens to the Earth as the moon gets farther away and will it ever go away entirely? (added 1st December 2011)
  15. Does the direction of the moon's crescent change through the night? (added 25th November 2011)
  16. Will Comet Elenin (C/2010 X1) affect the Earth on its close approach in Fall 2011? (added 21st June 2011)
  17. The Moon and Sun are the same apparent size in the sky. The Moon is moving away from us at 3.8 centimeters/year. Isn't it improbable that we live in an epoch in which they appear the same size in the sky? (added 17th June 2011)
  18. What happens to the helium formed in the sun? (added 17th June 2011)
  19. Wait, I'm still confused why information can't travel faster than the speed of light. (added 17th June 2011)
  20. How did a transit of Venus provide astronomers with the first measurement of the Earth-Sun distance? (added 17th June 2011)
  21. Where are the protons and electrons in a Neutron Star? (added 13th June 2011)
  22. Can we hear sound on Titan? (added 10th June 2011)
  23. Why can't a plane fly slowly and let the Earth pass underneath? (added 2nd October 2010)
  24. Does the singularity in a black hole create a new Universe? (added 3rd June 2010)
  25. Where is everybody? (added 5th January 2010)
  26. How has light from 13 billion years ago not passed us by? (added 27th October 2009)
  27. Is dark energy affected by black holes? (added 3rd September 2009)
  28. What are the possible ends of the universe? (added 3rd September 2009)
  29. What color are meteors? (added 3rd September 2009)
  30. Why does Titan, in spite of being smaller than Mars, have an atmosphere more dense than Earth's? (added 14th May 2009)
  31. Why does Mars have a dusty atmosphere? (added 6th April 2009)
  32. Is the reddish dust of Mars biogenic? (added 2nd March 2009)
  33. Is Earth-moon tidal friction causing global warming? (added 24th February 2009)
  34. Is the moon spherical? (added 24th February 2009)
  35. The naming of Mars (added 24th February 2009)
  36. When is the best time to observe zodiacal light? (added 9th February 2009)
  37. If there are infinity universes, will every thing that is possible happen? (added 28th October 2008)
  38. Will the Pioneer and Voyager probes ever leave the Milky Way? (added 28th October 2008)
  39. Does the particles involved in a star's final core collapse travel faster than the speed of light? (added 28th October 2008)
  40. If I were traveling through space, could I see distant galaxies with my own eyes? (added 28th October 2008)
  41. Do more meteorites fall at low latitudes? (added 17th September 2008)
  42. Can planets collide with one another? (added 17th September 2008)
  43. Does the Milky Way spin counter-clockwise? If so, do all spiral galaxies spin in this direction and why? (added 17th July 2008)
  44. Where is the Spitzer Space Telescope? (added 9th May 2008)
  45. When measuring the expansion of the universe, do astronomers consider that they're seeing how galaxies moved long ago, not today? (added 24th February 2008)
  46. Are there solar tides? (added 22nd February 2008)
  47. Is it sensible to consider terraforming Mars? (added 26th November 2007)
  48. When will humans travel to Mars and revisit the Moon? (added 15th November 2007)
  49. Can we prove that the Moon isn't hollow? (added 2nd November 2007)
  50. What would happen if a human were exposed to space without wearing a spacesuit? (added 1st November 2007)
  51. Can the sun rise from the west on Mars? (added 23rd October 2007)
  52. Do planets radiate noise? (added 12th October 2007)
  53. Are black holes spherical? (added 4th October 2007)
  54. When will Hale-Bopp return? (added 30th September 2007)
  55. Could a planetary system survive if its star merged with another, or if its star went supernova? (added 28th September 2007)
  56. If the Universe was infinitely dense at the Big Bang, why didn't time stand still? (added 21st September 2007)
  57. Did the Moon or planets form in a manner similar to that of Earth? (added 19th September 2007)
  58. Why don't skydivers burn up like meteors? (added 12th September 2007)
  59. Could the Universe's dark matter be made up of black holes? (added 12th September 2007)
  60. How do supernovae show us that the Universe's expansion is accelerating? (added 12th September 2007)
  61. Can we make a movie of the Milky Way galaxy's rotation? (added 12th September 2007)
  62. If nothing can escape a black hole, why do some black holes have jets? (added 10th September 2007)
  63. What is between the Oort cloud and the closest star? (added 6th September 2007)
  64. Has anyone ever seen a star "turn on"? (added 5th August 2007)
  65. Why are craters round? (added 22nd July 2007)
  66. Do the Earth's magnetic poles ever change places? (added 18th May 2007)
  67. How big is the Hubble Ultra Deep Field image? (added 6th April 2007)
  68. Is the green flash real? (added 12th March 2007)
  69. What color would Mars be if you were standing on it? (added 23rd February 2007)
  70. What would happen if a nuclear-powered shuttle exploded? (added 9th February 2007)
  71. Does weightlessness affect hunger? (added 9th February 2007)
  72. How can the universe be "flat"? We're 3D! (added 26th January 2007)
  73. How does the color index of a star relate to its actual color? (added 23rd January 2007)
  74. Do constellations looks the same from space? (added 18th December 2006)
  75. Is it a coincidence that we can have total solar eclipses? Are there other planets which also have them? (added 4th December 2006)
  76. What is the best way to see the Milky Way? (added 6th November 2006)
  77. How do we know the density of some extrasolar planets? (added 29th September 2006)
  78. Are aliens or UFOs real? (added 15th September 2006)
  79. How do we know what other planets (and stars, galaxies, etc.) are made of? (added 15th September 2006)
  80. If the sun went out and our atmosphere froze solid, what color would it be? (added 12th September 2006)
  81. On which days can I see the Moon in the evening / morning and why is this so? (added 8th September 2006)
  82. Do asteroids hit the sun? (added 4th September 2006)
  83. During close approaches, can Mars appear in our sky as large as the Moon? (added 8th August 2006)
  84. How can I find the star I have "bought"? (added 2nd June 2006)
  85. Can a human give birth in space? (added 21st May 2006)
  86. Does lunar gardening really work? (added 17th May 2006)
  87. The Moon slows the Earth's rotation, but how fast was it spinning billions of years ago? (added 8th May 2006)
  88. How close was the Moon to the Earth when it formed? (added 3rd May 2006)
  89. Will we discover an 11th planet? What would it be called? (added 1st May 2006)
  90. How can we discern different galaxies/clusters along the same line of sight? (added 30th April 2006)
  91. Can we harvest H & O from space to make water? (added 26th April 2006)
  92. How are sunspots formed? (added 25th April 2006)
  93. What is a wormhole? (added 25th April 2006)
  94. What is the most distant known galaxy? (added 10th March 2006)
  95. When can I see the Moon through the hole in the Pantheon? (added 7th March 2006)
  96. Why is Uranus tipped on its side? (added 26th February 2006)
  97. Could neutrinos be dark matter? (added 26th February 2006)
  98. What is Hot Dark Matter theory? (added 26th February 2006)
  99. Why is the sky blue and not blue & purple? (added 26th February 2006)
  100. Why does the Earth tilt back and forward once a year? (added 3rd February 2006)
  101. What's going to happen on December 21st 2012? (added 22nd January 2006)
  102. What do meteorites tell us about life on other planets? (added 15th January 2006)
  103. How much money is spent on space exploration? (added 10th November 2005)
  104. Is there really a 10th planet? (added 18th October 2005)
  105. Why are telescopes located in remote places? (added 5th October 2005)
  106. How do I explain to my children why the Moon has phases? (added 3rd October 2005)
  107. How do rockets work? (added 6th September 2005)
  108. How do photons from distant objects maintain enough energy to reach us? (added 3rd September 2005)
  109. Can moons have moons? (added 3rd September 2005)
  110. What if the Earth rotated twice as fast? (added 3rd September 2005)
  111. Is there oxygen in the atmospheres of other planets? (added 30th August 2005)
  112. Where do planetary rings come from, and what are they made of? (added 30th August 2005)
  113. Can you give me advice on buying a telescope? (added 12th August 2005)
  114. Why will fusion wait until hydrogen is gone before starting to fuse heavier atoms? (added 10th August 2005)
  115. How long would it take the Earth to fall into the Sun? (added 21st July 2005)
  116. Does the Sun have an iron surface? (added 14th July 2005)
  117. How much can the location of sunset differ from due West? (added 17th June 2005)
  118. What is the photoelectric effect? Why can't multiple low-frequency photons free an electron? (added 15th June 2005)
  119. How are planets detected around other stars? (added 2nd June 2005)
  120. What do astronauts do all day in the International Space Station? (added 2nd June 2005)
  121. How many Astronauts have been in space? (added 17th May 2005)
  122. Have astronomers observed any phenomena that could be produced by extraterrestrial civilizations? (added 11th May 2005)
  123. How do we determine the age of the universe? (added 10th May 2005)
  124. Can we feel the Earth spin? (added 10th May 2005)
  125. Which way does the sun travel in the southern hemisphere? (added 30th April 2005)
  126. How do astronomers measure the radius of a star? (added 29th April 2005)
  127. Why are accretion disks flat? (added 22nd April 2005)
  128. What happened to the girl who named Pluto? (added 23rd March 2005)
  129. Why do people draw stars with five points? (added 23rd March 2005)
  130. How do the astronauts communicate in space if sound cannot travel in a vacuum? (added 15th February 2005)
  131. Would the biggest airplanes cause tsunamis if they crashed? (added 5th February 2005)
  132. Can you describe a day on the job as an astronomer? (added 30th January 2005)
  133. How long could life on Earth survive if the Sun stopped shining? (added 30th January 2005)
  134. Why doesn't NASA build rotating spacecraft to simulate gravity? (added 30th January 2005)
  135. How can we compare dark matter and dark energy? (added 27th January 2005)
  136. How do we know that nuclear fusion is still going on in the Sun? (added 25th January 2005)
  137. What happens to spacetime inside a black hole? (added 15th January 2005)
  138. Is the universe really like an expanding balloon? (added 5th January 2005)
  139. What is the SU(3) quark model? (added 4th January 2005)
  140. If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths? (added 16th December 2004)
  141. How can observations of the distant universe prove that the expansion is accelerating *now*? (added 2nd December 2004)
  142. How can we understand the meaning of large numbers like "a million million?" (added 29th November 2004)
  143. Traveling at light speed, how long would it take to get to the nearest galaxy? (added 16th November 2004)
  144. What was different on Mars in the past to allow liquid water to be present? (added 12th November 2004)
  145. How many stars are born and die each day? (added 12th November 2004)
  146. Do we really observe the edges of galaxies at different epochs? (added 20th October 2004)
  147. How does the position of Moonrise and Moonset change? (added 6th October 2004)
  148. Why do humans want to go in space? (added 21st September 2004)
  149. How does Astronomy involve Chemistry? (added 16th September 2004)
  150. Is there a list of the sizes of different kinds of stars? (added 4th September 2004)
  151. How does melting a material reset its radioactive clock? (added 1st September 2004)
  152. Does the Moon rotate? (added 30th August 2004)
  153. Is there a project I can do on black holes? (added 30th August 2004)
  154. What are the names of the three stars in Orion's belt? (added 4th August 2004)
  155. Are names given to black holes? (added 30th July 2004)
  156. What's the difference between dark matter and dark energy? (added 21st July 2004)
  157. Are the planes of solar systems aligned with the plane of the Galaxy? (added 20th July 2004)
  158. What can I use for fuel in my homemade rocket? (added 15th July 2004)
  159. Where did the matter in the universe come from? (added 13th July 2004)
  160. Is the speed of light constant? (added 13th July 2004)
  161. How can you tell if a crescent moon is preceding or following a new-moon phase? (added 12th July 2004)
  162. What is the hottest time of day? (added 29th June 2004)
  163. Does the Mediterranean sea have tides? (added 29th June 2004)
  164. Would your weight change as you go underground? (added 29th June 2004)
  165. What happens when an antimatter black hole collides with a matter blackhole? (added 29th June 2004)
  166. Is Pluto a planet? (added 24th June 2004)
  167. How can we tell what the interiors of planets are like? (added 21st June 2004)
  168. How do we know the Milky Way is a spiral galaxy? (added 15th June 2004)
  169. Does Cerenkov radiation travel faster than light? (added 12th June 2004)
  170. How is the time of sunrise calculated? (added 11th June 2004)
  171. How long has there been water on Earth? (added 22nd May 2004)
  172. What was that eclipse I saw in the sky? (added 14th May 2004)
  173. What happens to a bullet fired on the moon? (added 18th April 2004)
  174. Why doesn't light from distant galaxies reach us instantaneously? (added 30th March 2004)
  175. Does the Sun rotate? (added 29th March 2004)
  176. How fast does the Earth go at perihelion and aphelion? (added 20th March 2004)
  177. Does Mt. Everest cast a shadow on the moon? (added 9th March 2004)
  178. Does quantum entanglement imply faster than light communication? (added 8th March 2004)
  179. When did people discover that the Sun is a star? (added 17th February 2004)
  180. Why is NASA shutting down the Hubble Space Telescope? (added 15th February 2004)
  181. Why is it easier to see a star if you look slightly to the side? (added 7th February 2004)
  182. How did Mars get so dusty? (added 7th February 2004)
  183. Why do airplanes take longer to fly West than East? (added 2nd February 2004)
  184. Did the speed of light change over the history of the universe? (added 2nd February 2004)
  185. When will Halley's Comet return? (added 29th January 2004)
  186. Is the Great Wall the largest galaxy cluster? (added 24th January 2004)
  187. When are there 5 Sundays in February? (added 23rd January 2004)
  188. Why is the WMAP picture of the CMB an ellipse? (added 22nd January 2004)
  189. Are Kuiper Belt Objects asteroids? Are large Kuiper Belt Objects planets? (added 19th January 2004)
  190. What is the evidence supporting the nebula theory of Solar System formation? (added 17th January 2004)
  191. Can superheavy elements (such as Z=116 or 118) be formed in a supernova? Can we observe them? (added 14th January 2004)
  192. What causes gamma ray bursts? (added 11th January 2004)
  193. Why does Barnard 68 appear dark? (added 19th December 2003)
  194. How many comets are currently orbiting our sun? (added 19th December 2003)
  195. Why is a day divided into 24 hours? (added 18th December 2003)
  196. Could someone travel the universe in his or her own lifetime? (added 11th December 2003)
  197. Can I communicate faster than light? (added 4th December 2003)
  198. How can we find galaxies behind the Milky Way? (added 4th December 2003)
  199. Can any galaxies be seen with the naked eye? (added 2nd December 2003)
  200. Why can we see the sun's image before sunrise and after sunset? (added 2nd December 2003)
  201. How do unmanned space probes avoid running into things? (added 22nd November 2003)
  202. Has anyone made a map of the Milky Way? (added 16th November 2003)
  203. Why did the Pioneer and Voyager take only 2 years to reach Jupiter, while Galileo and Cassini took more than 5 years? (added 10th November 2003)
  204. Why are there more maria on the near side of the Moon? (added 7th November 2003)
  205. Which part of the sky did the famous 'wow' signal originate from? (added 3rd November 2003)
  206. Would extraterrestrial civilizations know that there is life on Earth? (added 29th October 2003)
  207. How can I find the distance to the Sun on any given day? (added 20th October 2003)
  208. What is the best time of the year to see eclipses? (added 16th October 2003)
  209. Did time go slower just after the Big Bang? (added 15th October 2003)
  210. Will the Moon be invisible in 500 million years? (added 14th October 2003)
  211. Have astronomers discovered Earth's second moon? (added 20th September 2003)
  212. Why doesn't the hydrogen on Jupiter explode? (added 19th September 2003)
  213. Is there a "South Star"? (added 18th September 2003)
  214. Is the universe expanding faster than the speed of light? (added 18th September 2003)
  215. Does a photon observe other photons moving past it at the speed of light? (added 16th September 2003)
  216. What is the speed of gravity? (added 15th September 2003)
  217. How long would it take for a mini-black hole to eat the Earth? (added 9th September 2003)
  218. Could a different theory of gravity explain the dark matter mystery? (added 8th September 2003)
  219. Did the Sumerians measure precession? (added 5th September 2003)
  220. What is apparent magnitude? (added 4th September 2003)
  221. How does a star take mass from another star? (added 28th August 2003)
  222. What is our galaxy's halo made of, and how was it formed? (added 28th August 2003)
  223. What do a galaxy's colors mean? Are they its true colors? (added 28th August 2003)
  224. Can astronauts play musical instruments in space? (added 27th August 2003)
  225. How far is each planet from Earth? (added 25th August 2003)
  226. When the Sun converts mass to energy, do the orbits of the planets change? (added 6th August 2003)
  227. Are there any new craters on the moon? (added 5th August 2003)
  228. Where is the supernova remnant that led to our solar system? (added 4th August 2003)
  229. Will astronauts ever be able to go ice-skating on Europa? (added 4th August 2003)
  230. Could you escape from a black hole if you were able to go faster than the speed of light? (added 4th August 2003)
  231. Do unmanned spacecraft like Voyager travel in straight lines? (added 29th July 2003)
  232. What other careers involve Astronomy besides Astronomer? (added 27th July 2003)
  233. What makes the wind? (added 16th July 2003)
  234. Why are there active volcanos on Io? (added 16th July 2003)
  235. How do scientists slow light down? (added 16th July 2003)
  236. What kinds of cancer research have been done in space? (added 16th July 2003)
  237. What is the pattern to the distances between each planet and the sun? (added 16th July 2003)
  238. What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (added 16th July 2003)
  239. Did I see the Aurora Borealis as a child? (added 15th July 2003)
  240. What is the observational difference between a star and a planet? (added 3rd July 2003)
  241. What is the physical difference between a star and a planet? (added 18th June 2003)
  242. If Mars is only about 35-60 million miles away at close approach, why does it take 6-8 months to get there? (added 18th June 2003)
  243. Since Earth is spinning, why do we land in the same place when we jump or fall? (added 18th June 2003)
  244. What is the difference between nutation and precession of the Earth? (added 10th June 2003)
  245. How many stars can I see? (added 9th June 2003)
  246. Why does the apparent density of galaxies drop off at larger distances? (added 9th June 2003)
  247. If clocks run slow in a gravitational field, how can we know the true age of the Solar System and Universe? (added 8th June 2003)
  248. Where did the Universe come from? (added 8th June 2003)
  249. Do asteroids ever do anything good in the Solar System? (added 8th June 2003)
  250. How long is twilight on the Moon? (added 8th June 2003)
  251. How do astronauts take baths and use restrooms in space? (added 8th June 2003)
  252. How do we know that superclusters are the largest structures in the universe? (added 7th June 2003)
  253. How are astronomy and poetry linked? (added 6th June 2003)
  254. What is a graviton? (added 4th June 2003)
  255. Who has landed on the moon? (added 3rd June 2003)
  256. How long do supernova remnants last? (added 24th May 2003)
  257. Is there such a thing as hyperspace? (added 18th May 2003)
  258. No matter how fast the universe is expanding, shouldn't gravity eventually make it recollapse? (added 14th May 2003)
  259. Can other terrestrial moons be (or have been) stable? (added 9th May 2003)
  260. Why do the size and brightness of the full moon change? (added 6th May 2003)
  261. Can I listen to the SETI@home radio signal? (added 6th May 2003)
  262. Is there sound coming from the Sun? (added 2nd May 2003)
  263. Could matter-anti-matter repulsion power the expansion of the universe? (added 1st May 2003)
  264. Why is it difficult to understand the expansion of the universe? (added 29th April 2003)
  265. Where was the water in the big bang? (added 29th April 2003)
  266. Will the magnetic field of the Earth reverse its direction in the future? Will this cause problems? (added 29th April 2003)
  267. How can I nominate myself for a Nobel Prize in Physics? (added 23rd April 2003)
  268. Can supernovae hinder the formation of life in galaxies? (added 18th April 2003)
  269. How do we know that sunspots are associated with the Sun's magnetic field? (added 14th April 2003)
  270. Do similar laws of physics throughout the Universe imply that all life must be like life on Earth? (added 14th April 2003)
  271. Why don't people walk upside-down on the bottom of the Earth? (added 14th April 2003)
  272. What is "nothing", from a scientific point of view? (added 12th April 2003)
  273. What would happen to us if the sun went out for an hour? (added 12th April 2003)
  274. Does the Coriolis force determine which way my toilet drains? Does it affect black holes? (added 10th April 2003)
  275. Why do so many of the world's UFO sightings happen in America? (added 6th April 2003)
  276. Does inflation allow for an infinite number of universes? (added 6th April 2003)
  277. Can the Space Shuttle abort and return to Earth before reaching orbit? (added 4th April 2003)
  278. Can you use an infinite line of reflectors to send light to the edge of the Universe? (added 4th April 2003)
  279. What would happen if a supermassive black hole came close to the Earth? (added 27th March 2003)
  280. Is it possible to count the stars? (added 26th March 2003)
  281. How many constellations are there? (added 26th March 2003)
  282. What do "homogeneity" and "isotropy" mean? (added 26th March 2003)
  283. Considering the motion of the Earth, the solar system, and the galaxy, how fast am I moving while lying in bed asleep? (added 26th March 2003)
  284. If the universe is "bounded" today, could it one day become "unbounded"? (added 25th March 2003)
  285. What would an "open geometry" for the universe look like? (added 25th March 2003)
  286. Don't tachyons travel faster than light? (added 23rd March 2003)
  287. What calculations go into predicting eclipses? (added 20th March 2003)
  288. Do stars' orbits in galaxies obey Kepler's Laws? (added 17th March 2003)
  289. How fast do particles travel in space? (added 9th March 2003)
  290. What is the relationship between the width of a star trail on a photo and the star's intensity? (added 9th March 2003)
  291. Will the diameter of a cluster of galaxies change with redshift? (added 9th March 2003)
  292. Why does the location of sunrise change? (added 9th March 2003)
  293. If a white dwarf is a "dead" star, why is it so hot? (added 9th March 2003)
  294. How will a change in the speed of light affect the evolution of the Universe? (added 9th March 2003)
  295. Has there been an experiment that measured speed faster than the speed of light in vacuum? (added 9th March 2003)
  296. How are astronauts trained for weightlessness? (added 9th March 2003)
  297. How long does it take the Big Dipper to move in the sky? (added 9th March 2003)
  298. How can the Sun have such a strong gravitational field if it's made of gasses? (added 9th March 2003)
  299. How is it that we see farther out in space (farther back in time) than in the past? (added 9th March 2003)
  300. How long has humanity known that we live in a galaxy similar to others in the Universe? (added 8th March 2003)
  301. Does the temperature of matter increase as it is accelerated to relativistic speeds? (added 8th March 2003)
  302. What is the origin of the stellar classification system "OBAFGKM"? (added 8th March 2003)
  303. How are planets affected by the Hot Ionised Medium? (added 8th March 2003)
  304. Can I see a quasar? (added 7th March 2003)
  305. Is the Local Group expanding along with the entire Universe? (added 7th March 2003)
  306. What is happening just around the black hole in the center of the Milky Way? (added 6th March 2003)
  307. What is the difference between a "star" and a "sun"? (added 6th March 2003)
  308. What are the atmospheres of Mars and Pluto like? (added 6th March 2003)
  309. Why do the planets orbit the sun? (added 6th March 2003)
  310. How do I make a scale model of the Solar System? (added 5th March 2003)
  311. How does the parachute in a model rocket work? (added 4th March 2003)
  312. How do we detect incoming meteorites? (added 4th March 2003)
  313. What is the biggest crater recorded on Earth? (added 4th March 2003)
  314. If the universe is infinite does that mean there is an infinite number of "me"s? (added 3rd March 2003)
  315. How is astronomy impacted by trigonometry? (added 3rd March 2003)
  316. Who came up with the name "black hole"? (added 3rd March 2003)
  317. Where is the nearest black hole? (added 3rd March 2003)
  318. Can terrestrial planets have rings? (added 27th February 2003)
  319. Can you fire a gun on the Moon? (added 18th February 2003)
  320. How many meteorites hit Earth each year? (added 18th February 2003)
  321. What's the biggest meteorite? (added 18th February 2003)
  322. What makes up most of the Universe? (added 18th February 2003)
  323. Why do planets have elliptical orbits? (added 16th February 2003)
  324. Did I find a rock that came from the Moon? (added 10th February 2003)
  325. Does gravity vary across the surface of the Earth? (added 9th February 2003)
  326. Is it worthwhile to continue the search for extraterrestrial life? (added 4th February 2003)
  327. How much longer will the Earth last? (added 4th February 2003)
  328. Can we colonize other planets? (added 4th February 2003)
  329. Does the Sun orbit the Earth as well as the Earth orbiting the Sun? (added 4th February 2003)
  330. Can I buy land on the Moon? (added 4th February 2003)
  331. How far does a galaxy extend? (added 3rd February 2003)
  332. How can we see galaxies if their stars are so faint? (added 3rd February 2003)
  333. Did I really hear a meteor? (added 2nd February 2003)
  334. Why is sea water salty, and not lake water? (added 1st February 2003)
  335. Why is pressure broadening greater in low mass stars than in high mass stars? (added 1st February 2003)
  336. Do we have to worry about relativity when studying galactic objects? (added 1st February 2003)
  337. How are galaxy distances inferred from their recessional velocities? (added 31st January 2003)
  338. Why do we assume that the universe is homogeneous? (added 28th January 2003)
  339. How do you measure a planet's mass? (added 27th January 2003)
  340. Where did the name 'Earth' come from? (added 25th January 2003)
  341. Why doesn't the ammonia and methane in Jupiter's atmosphere sink into the core? (added 22nd January 2003)
  342. How do bars form in spiral galaxies? (added 22nd January 2003)
  343. Why is the Moon so bright? (added 22nd January 2003)
  344. Could there be life in the galaxies nearest to the Milky Way? (added 20th January 2003)
  345. Why do spacecraft need heat shields coming back to Earth but not leaving? (added 20th January 2003)
  346. How can we estimate the number of Earth-like planets in the Galaxy? (added 20th January 2003)
  347. Could photons be dark matter? (added 20th January 2003)
  348. What process would bring about a quark star? (added 20th January 2003)
  349. Can "tired light theory" explain the observed redshifts of galaxies? (added 17th January 2003)
  350. Is light blueshifted when it is gravitationally lensed? (added 17th January 2003)
  351. Are there eclipses on other planets? (added 16th January 2003)
  352. Does evolution contradict the second law of thermodynamics? (added 16th January 2003)
  353. Are Earth and the Moon "twin planets"? (added 12th January 2003)
  354. How can I find my age on another planet? (added 10th January 2003)
  355. Why have star signs shifted by one constellation? (added 8th January 2003)
  356. Which American colleges teach astronomy? (added 8th January 2003)
  357. How do we define distance in an expanding universe? (added 3rd January 2003)
  358. How can we see the Milky Way if we are inside it? (added 22nd December 2002)
  359. How does the brightness of a star depend on its distance from us? (added 22nd December 2002)
  360. When we look back to the Big Bang, why don't we see the universe as a tiny speck of matter? (added 21st December 2002)
  361. How different would the night sky have looked in 40,000 B.C.? (added 16th December 2002)
  362. Why don't astronomers use everyday units to measure distances (what is an AU or a pc)? (added 16th December 2002)
  363. Is the Sun always up for exactly 12 hours at the equator? (added 14th December 2002)
  364. How do astronomers observe the Sun's interior? (added 14th December 2002)
  365. Why aren't discoveries of extrasolar planets reported on the news? (added 12th December 2002)
  366. Is Andromeda part of the Milky Way? Where can I find them in the sky? (added 11th December 2002)
  367. How do I become both an astronaut and an astronomer? (added 10th December 2002)
  368. How does the Earth compare in size to the entire universe at the present epoch? (added 9th December 2002)
  369. What are some astronomy science fair projects? (added 9th December 2002)
  370. How can water be chemically trapped in rocks? (added 6th December 2002)
  371. Is time travel possible? (added 6th December 2002)
  372. How would the weather on Earth be different if it were a cube? (added 6th December 2002)
  373. Why are Saturn's rings flat? (added 5th December 2002)
  374. Can you see the future as you fall into a black hole? (added 5th December 2002)
  375. How do astronauts communicate with their families from space? (added 3rd December 2002)
  376. How does astronomy benefit humankind? (added 3rd December 2002)
  377. Why do planets rotate? (added 3rd December 2002)
  378. Which constellation does our Sun belong to? (added 2nd December 2002)
  379. What are the largest radio wavelengths observed from radio sources in the sky? (added 2nd December 2002)
  380. Does the Sun have any heavy elements? (added 2nd December 2002)
  381. What is the largest galaxy? (added 27th November 2002)
  382. A line drawn perpendicular to a line through the tips of the horns of the crescent moon doesn't point to the Sun! Why not? (added 25th November 2002)
  383. How do we know what parameters to use when simulating the collision of the Milky Way and Andromeda? (added 23rd November 2002)
  384. Why is looking out into space the same as looking back in time? (added 23rd November 2002)
  385. Why don't astronauts sublimate in space? (added 23rd November 2002)
  386. Could we send a manned mission to the outer planets? (added 23rd November 2002)
  387. What are collections of galaxies called? (added 21st November 2002)
  388. Why doesn't the length of each day change much around the solstices? (added 21st November 2002)
  389. Did a giant impact cause the Dark Ages? (added 21st November 2002)
  390. How will the two black holes that are going to collide affect Earth? (added 20th November 2002)
  391. How often does the Sun pass through a spiral arm in the Milky Way? (added 19th November 2002)
  392. Will the Leonid meteor shower go away? (added 18th November 2002)
  393. How do you measure the distance between Earth and the Sun? (added 17th November 2002)
  394. How dangerous are the asteroids? (added 17th November 2002)
  395. How big a change in the Earth's orbit would be required to destroy all life? (added 15th November 2002)
  396. Why do supernova remnants look like rings rather than spheres? (added 13th November 2002)
  397. Which planet is most similar to Earth? (added 13th November 2002)
  398. What kind of instruments are used to detect extrasolar planets? (added 13th November 2002)
  399. Are the properties of extrasolar planets known? (added 13th November 2002)
  400. Is the Moon seen as a crescent (and not a "boat") all over the world? Is the same phase of the moon visible from the Northern and Southern hemispheres? (added 12th November 2002)
  401. Can we see dead stars with the naked eye? (added 12th November 2002)
  402. What was that really big falling star that I saw? (added 12th November 2002)
  403. Why are there stars? (added 12th November 2002)
  404. How do you calculate the lifetime of the Sun? (added 11th November 2002)
  405. How do sunrise and sunset times change with altitude? (added 10th November 2002)
  406. How can the Universe expand faster than the speed of light during inflation? (added 9th November 2002)
  407. Is the Milky Way a collision of two galaxies? (added 8th November 2002)
  408. What kind of eyepieces do I need to look at planets? (added 8th November 2002)
  409. Are there stars outside of galaxies? (added 8th November 2002)
  410. Are there any 'lonely galaxies'? (added 8th November 2002)
  411. What would happen if two stars collided? (added 7th November 2002)
  412. Do we see the same stars from above and below the equator? (added 7th November 2002)
  413. Is light of different colors affected differently by gravity? (added 7th November 2002)
  414. Why is the moon in a different place every night? (added 7th November 2002)
  415. How do stars move in the Galaxy? (added 7th November 2002)
  416. What is the largest star? (added 7th November 2002)
  417. How are supernovae discovered? (added 7th November 2002)
  418. Why isn't the sky bright at night if the universe has so many stars? (added 5th November 2002)
  419. What is the size of the Solar System? (added 5th November 2002)
  420. How does the Sun compare to other stars? (added 5th November 2002)
  421. Who named the planets and who decides what to name them? (added 4th November 2002)
  422. Do stars move in the sky? (added 4th November 2002)
  423. What is the typical size of a visible shooting star? (added 3rd November 2002)
  424. How can I find out if the new moon has been sighted? (added 2nd November 2002)
  425. What are the closest and/or brightest stars? (added 1st November 2002)
  426. Why do astronauts in space need to exercise? (added 1st November 2002)
  427. Why hasn't NASA gone back to the moon? (added 1st November 2002)
  428. What is Earthrise over the Moon? (added 1st November 2002)
  429. What was there before the Big Bang and what is there outside of our universe? (added 1st November 2002)
  430. Can any comparison be made between spiral galaxies and hurricanes? (added 1st November 2002)
  431. Wouldn't the Big Bang theory be considered a hypothesis and not a theory? (added 29th October 2002)
  432. What is dark matter? (added 29th October 2002)
  433. What would happen if there was a collision between two white dwarfs? (added 28th October 2002)
  434. How do you calculate the azimuth and altitude of an object? (added 28th October 2002)
  435. Why doesn't dark matter fall into a black hole? (added 28th October 2002)
  436. Do binary or triple star systems form together? (added 28th October 2002)
  437. At what speed does the earth move around the sun? (added 28th October 2002)
  438. How do we find out about the star formation histories of galaxies? (added 26th October 2002)
  439. How do galaxies collide in an expanding universe? (added 26th October 2002)
  440. What are quasars made of? (added 25th October 2002)
  441. Why do we study black holes? (added 25th October 2002)
  442. What happens when galaxies collide? (added 25th October 2002)
  443. Can I build an instrument to measure the size of the Sun and of the Moon? (added 25th October 2002)
  444. How are black holes made? Could one be made close to us? (added 25th October 2002)
  445. What would you see from inside a black hole? (added 25th October 2002)
  446. What companies or businesses can astronomers work for? (added 24th October 2002)
  447. How fast is the Universe expanding? (added 24th October 2002)
  448. How are light and heavy elements formed? (added 23rd October 2002)
  449. Why doesn't SETI concentrate its observations to the nearby stars and the solar systems that we are discovering? (added 23rd October 2002)
  450. Why is the time between two successive full moons different from the lunar synodic month? (added 23rd October 2002)
  451. What is the mass of the Universe? (added 23rd October 2002)
  452. Is it possible to see the full Moon and the Sun simultaneously in high northern latitudes when the Sun doesn't set? (added 23rd October 2002)
  453. What are constellations used for? (added 23rd October 2002)
  454. Will the next generation telescope OWL be able to detect an Earth like extrasolar planet? (added 23rd October 2002)
  455. How much power is contained in a beam of light? (added 23rd October 2002)
  456. Wouldn't the vast distances of space distort SETI signals into unintelligeble forms? (added 23rd October 2002)
  457. What would happen if the Moon fell out of its orbit around Earth? (added 23rd October 2002)
  458. Are planetary nebulae the result of supernovae? (added 23rd October 2002)
  459. What is the significance of the second focus of elliptical orbits of planets in our Solar System? (added 23rd October 2002)
  460. How do planets capture satellites? (added 23rd October 2002)
  461. Why are stars of different masses? (added 23rd October 2002)
  462. How critical is the Earth-Sun distance in maintaining our average temperatures on Earth? (added 23rd October 2002)
  463. Why does one side of Mars look more catastrophic than the other? (added 23rd October 2002)
  464. What makes the Earth rotate? (added 23rd October 2002)
  465. Can two lunar eclipses occur in the same month? (added 22nd October 2002)
  466. What happens when two black holes get too close? (added 21st October 2002)
  467. How do I become an astronomical artist? (added 21st October 2002)
  468. Can double stars have planets? (added 20th October 2002)
  469. What is the largest structure in the universe? (added 19th October 2002)
  470. What is the farthest in space that we have gone? (added 18th October 2002)
  471. Where does the kinetic energy of infalling bodies come from? (added 17th October 2002)
  472. What are the facts about the Star of Bethlehem? (added 17th October 2002)
  473. How do we measure the size of the Moon and of the Sun? (added 17th October 2002)
  474. How long does a solar eclipse last? (added 16th October 2002)
  475. Is the distance from the Earth to the Sun changing? (added 16th October 2002)
  476. What would the Big Crunch look like to an observer on Earth? (added 15th October 2002)
  477. Why aren't accretion disks around giant stars as hot as accretion disks around black holes? (added 12th October 2002)
  478. Why are telescopes kept in cold conditions? (added 11th October 2002)
  479. What is the approximate GPA needed in High School in Math and Science to be an astronomer? (added 11th October 2002)
  480. What are the advantages and disadvantages of using a telescope in space? (added 11th October 2002)
  481. Why is the Hubble Space Telescope in space? (added 11th October 2002)
  482. Does your weight change between the poles and the equator? (added 11th October 2002)
  483. How can we distinguish a star's "real" color from the change in color that we observe due to the star's motion? (added 10th October 2002)
  484. What are some of the effects of solar flares on Earth? (added 10th October 2002)
  485. How do solar flares affect airline pilots? (added 10th October 2002)
  486. Would a planet near the galactic center have a brighter night sky? (added 10th October 2002)
  487. What kind of interference must astronomers contend with when observing? (added 9th October 2002)
  488. What percent of the time can astronomers observe without interference from the Moon? (added 9th October 2002)
  489. Can astronomers observe anything when the moon is full? (added 9th October 2002)
  490. How can I calculate distances between stars? (added 9th October 2002)
  491. How many moles of stars are in the known universe? (added 9th October 2002)
  492. Why do different stars appear with seasons? (added 9th October 2002)
  493. How do we weigh objects in space? (added 9th October 2002)
  494. What is a star's "spectrum"? (added 8th October 2002)
  495. What are "blue stragglers" in globular clusters? (added 8th October 2002)
  496. What can we learn from the color of a star? (added 8th October 2002)
  497. Is there a beginning and an end to a galaxy's life? (added 8th October 2002)
  498. Will we ever stop having solar eclipses because of the moon's motion away from the Earth? (added 8th October 2002)
  499. Why do some eclipses take longer than others? (added 8th October 2002)
  500. How can I measure the distance of a star? (added 7th October 2002)
  501. Why does the Sun's apparent path through the sky change throughout the year? (added 4th October 2002)
  502. Is the Earth slowly getting larger? (added 4th October 2002)
  503. What are the names of the earth, moon, sun, and solar system? (added 4th October 2002)
  504. How do astronomers come up with their facts? (added 3rd October 2002)
  505. Can a person go into a black hole and come out alive? (added 3rd October 2002)
  506. Could an astronaut or satellite fall into a black hole that we didn't know about? (added 3rd October 2002)
  507. Will the sun go supernova in six years and destroy Earth (as seen on Yahoo)? (added 2nd October 2002)
  508. What would happen if the gravity on Earth was suddenly turned off? (added 1st October 2002)
  509. When is the next comet due to arrive? (added 1st October 2002)
  510. Could our position in the universe affect our perceptions of the expansion? (added 30th September 2002)
  511. Why do pictures of distant galaxies have higher resolution than those of nearby planets? (added 30th September 2002)
  512. Why are the Moon and Sun sometimes orange or red? (added 30th September 2002)
  513. Could there have been multiple Big Bangs at different places in the universe? (added 29th September 2002)
  514. What is the difference between the "Doppler" redshift and the "gravitational" or "cosmological" redshift? (added 29th September 2002)
  515. Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background? (added 29th September 2002)
  516. Could dark energy come from matter anti-matter pairs forming spontaneously and then annihilating? (added 29th September 2002)
  517. What does the term "visible universe" mean? (added 29th September 2002)
  518. What is the universe expanding into? (added 29th September 2002)
  519. How do astronauts use math in their jobs? (added 29th September 2002)
  520. How do astronomers use math in their jobs? (added 29th September 2002)
  521. Do astronomers believe in astrology? (added 29th September 2002)
  522. Are time machines possible? (added 29th September 2002)
  523. Who first measured the speed of light? (added 29th September 2002)
  524. How can geometry be different in space? (added 29th September 2002)
  525. How powerful are quasars? (added 29th September 2002)
  526. Why doesn't gravity change the speed of light? (added 29th September 2002)
  527. Do dead stars still shine? (added 29th September 2002)
  528. How do gravitons escape black holes to tell the universe about their gravity? (added 29th September 2002)
  529. What happens when you change the mass of a White Dwarf or Neutron Star? (added 29th September 2002)
  530. How do you measure the mass of a star? (added 29th September 2002)
  531. How can we measure distances to more stars? (added 29th September 2002)
  532. Can one star orbit another? (added 29th September 2002)
  533. How did the stars get named? (added 27th September 2002)
  534. If we invented special suits could we ever go to the sun? (added 27th September 2002)
  535. How hot is each one of the layers of the sun? (added 27th September 2002)
  536. How many sunspots can the Sun have at once? (added 27th September 2002)
  537. Do we know everything about the Sun? (added 27th September 2002)
  538. What is the solar cycle? (added 27th September 2002)
  539. Is the gravitational force exerted by the Earth on the Moon equal to the centripetal force acting on the Moon? (added 27th September 2002)
  540. What is the three-body problem? (added 27th September 2002)
  541. How do asteroids, meteors and comets disappear? (added 27th September 2002)
  542. What are shooting stars? (added 26th September 2002)
  543. Have there been other Big Bangs before? (added 26th September 2002)
  544. What would happen if Earth had more than one moon? (added 23rd September 2002)
  545. Why does the Earth have only one moon? (added 23rd September 2002)
  546. Who (and when) discovered that the earth's axis is on a 23 degree tilt? (added 23rd September 2002)
  547. What elements make up the Sun? (added 23rd September 2002)
  548. How are galaxies and solar systems similar? (added 23rd September 2002)
  549. How can a star burn with no oxygen? (added 23rd September 2002)
  550. How does interferometry work? (added 22nd September 2002)
  551. What do stellar classifications mean? (added 22nd September 2002)
  552. Why do stars change colour when they twinkle? (added 22nd September 2002)
  553. Could we be seeing dead stars? (added 22nd September 2002)
  554. How do we measure distances to other stars? (added 22nd September 2002)
  555. What color is each planet? (added 22nd September 2002)
  556. What kinds of star clusters are there? (added 21st September 2002)
  557. What is a nova? (added 21st September 2002)
  558. Where are stars born? (added 21st September 2002)
  559. Is the Sun expanding? Will it ever explode? (added 20th September 2002)
  560. Do most astronomers believe in God based on the available scientific evidence? (added 19th September 2002)
  561. What is the density of a black hole? (added 19th September 2002)
  562. Why does the Sun appear larger on the horizon than overhead? (added 18th September 2002)
  563. Do the magnitudes and colors of stars ever change? (added 18th September 2002)
  564. How close does a supernova need to be to damage the Earth's environment? (added 18th September 2002)
  565. What are the different kinds of astronomers? (added 18th September 2002)
  566. What makes a satellite geosyncronise itself with Earth's orbit? (added 18th September 2002)
  567. As the universe expands, why don't galaxies get stretched out? (added 18th September 2002)
  568. If comets are boiling away, why are there any left? (added 18th September 2002)
  569. Why is it important to study meteorites? (added 18th September 2002)
  570. Could we send a space mission to a comet? (added 18th September 2002)
  571. How did asteroids form and what is the difference between an asteroid and a comet? (added 18th September 2002)
  572. What's the object I saw that moved across the sky and then got very bright? (added 18th September 2002)
  573. What happened to all the black holes that were around in the early universe? (added 17th September 2002)
  574. What caused Shoemaker-Levy 9 to split up? (added 17th September 2002)
  575. Can HST see the Oort cloud? (added 17th September 2002)
  576. Are meteorites hot or cold when they hit Earth? (added 17th September 2002)
  577. Are the asteroids the remains of a planet which broke apart? (added 17th September 2002)
  578. Why are there no craters on Earth? Did all the meteorites miss us? (added 16th September 2002)
  579. When unmanned spacecraft accelerate in space, what causes them to slow down? (added 16th September 2002)
  580. Why do most moons orbit their planets at the equator? (added 16th September 2002)
  581. How can two moons of Saturn share the same orbit? (added 16th September 2002)
  582. What is a Dyson Sphere? (added 16th September 2002)
  583. Why doesn't the earliest sunset occur on the shortest day of the year? (added 16th September 2002)
  584. How do we know the mass of the Earth and the Moon? (added 12th September 2002)
  585. Which planets have rings? (added 12th September 2002)
  586. Why do all the planets orbit in the same plane? (added 12th September 2002)
  587. Can the theory of formation of the solar system explain all the observables? (added 12th September 2002)
  588. When was the last time all 9 planets were aligned? (added 12th September 2002)
  589. Do the Sun's or Earth's magnetic field reverse? (added 11th September 2002)
  590. Why search for only Earth-like life on other planets? (added 11th September 2002)
  591. What are the requirements for being a planet? (added 11th September 2002)
  592. What is the origin of spiral structure in galaxies? (added 9th September 2002)
  593. Why is our solar system so different from all the others we've found? (added 6th September 2002)
  594. How long does it take for the Sun's light to reach us? (added 6th September 2002)
  595. What causes seasons? (added 6th September 2002)
  596. Where did all the water in the universe come from? (added 6th September 2002)
  597. How does light pollution affect astronomers? (added 6th September 2002)
  598. What causes a particle to decay? (added 2nd September 2002)
  599. How does the Moon stay "suspended" in the air? (added 2nd September 2002)
  600. How close do you have to come to the Earth to be influenced by its gravity? (added 30th August 2002)
  601. Is there a proof that Earth moves? (added 29th August 2002)
  602. Can the acceleration of the Universe be analogous to apparent acceleration in a airplane? (added 29th August 2002)
  603. How can I contribute to science as an amateur astronomer? (added 27th August 2002)
  604. Why are most months 30 or 31 days long? (added 26th August 2002)
  605. How does the location of sunrise and sunset change throughout the year? (added 26th August 2002)
  606. What will happen to the Milky Way in the future? (added 26th August 2002)
  607. Can you tell me the characteristics of W, R, N and S type stars? (added 26th August 2002)
  608. Why do the explosions of Type Ia supernovae have a more predictable spectrum than those of regular Type II supernovae? (added 26th August 2002)
  609. Is there a simple formula to calculate solar eclipse timings from any position on Earth? (added 26th August 2002)
  610. Was the Sun made in a supernova? (added 26th August 2002)
  611. Why isn't the summer solstice the hottest day of the year? (added 26th August 2002)
  612. Is it possible for amateurs to do optical interferometry? (added 26th August 2002)
  613. What are the "dog days of summer"? (added 24th August 2002)
  614. Why can't we see Venus at night when it is an inner planet? (added 24th August 2002)
  615. Is it possible to build a cheap device to measure declination? (added 24th August 2002)
  616. What is meant by "stopping down a telescope"? (added 24th August 2002)
  617. Why do we see stars? (added 24th August 2002)
  618. Will winter and summer constellations change due to abnormal warmth or cold on Earth? (added 24th August 2002)
  619. Why is the Cosmic Microwave Background not absorbed by interstellar hydrogen? (added 24th August 2002)
  620. Why is the Universe flat and not spherical? (added 24th August 2002)
  621. What are "curled" dimensions? (added 24th August 2002)
  622. How is it proved that the Universe is expanding? (added 24th August 2002)
  623. Why was the Platonic year named after Plato? (added 24th August 2002)
  624. Could the Universe have expanded faster than the speed of light at the Big Bang? (added 23rd August 2002)
  625. What is at the end of the Universe? (added 23rd August 2002)
  626. Is time travel possible using merging black holes? (added 23rd August 2002)
  627. What are black holes made of? (added 23rd August 2002)
  628. Do black holes die? If so how? (added 23rd August 2002)
  629. If light has no mass, then what draws it into a black hole? (added 23rd August 2002)
  630. Is there any possibility that the Solar System or the Universe is in a black hole? (added 23rd August 2002)
  631. What is the size of a black hole? (added 23rd August 2002)
  632. Can a black hole come back to the visual universe through a "little bang"? (added 23rd August 2002)
  633. Are there any dark stars or dark galaxies made of dark matter? (added 23rd August 2002)
  634. How are galaxies formed? (added 23rd August 2002)
  635. Will the Sun become a black hole one day? (added 23rd August 2002)
  636. Does the Sun have a scientific name? (added 23rd August 2002)
  637. Is the Earth at the centre of the Universe? (added 22nd August 2002)
  638. What's that dark spot on the Sun? (added 21st August 2002)
  639. Why do photos of space taken from space never show any stars? (added 14th August 2002)
  640. Can I calculate the size of the Universe by converting light years to kilometres? (added 14th August 2002)
  641. Do supermassive black holes cause galaxy rotation? (added 13th August 2002)
  642. Can I see details on Venus? (added 13th August 2002)
  643. How can I watch the Perseid meteor shower? (added 9th August 2002)
  644. How can I calculate the position or path of the Sun for a given time and location? (added 9th August 2002)
  645. What would happen if an asteroid 10 kilometers across hit the Earth? (added 27th July 2002)
  646. Why can't relative velocities add up to more than the speed of light? (added 26th July 2002)
  647. Are there any asteroids on a collision course with Earth? (added 24th July 2002)
  648. Why are there both high and low tides? (added 19th July 2002)
  649. Does the Moon rotate? Are there other moons that always keep one face toward their planet? (added 18th July 2002)
  650. Why can we have solar eclipses? (added 10th July 2002)
  651. Was I hit by a meteorite? (added 10th July 2002)
  652. Is there any limitation to what a black hole can "suck" in? (added 10th July 2002)
  653. What happens to the material that has been sucked into a black hole? (added 10th July 2002)
  654. Where, in relation to the entire universe, is the Milky Way located? (added 10th July 2002)
  655. Is infinite temperature possible? (added 7th July 2002)
  656. What's so exciting about the new planet around 55 Cancri? (added 5th July 2002)
  657. Are there telescopes that can see the flag and lunar rover on the Moon? (added 15th June 2002)
  658. Can astronauts produce water in space? (added 12th June 2002)
  659. What do astronauts eat in space? Can they grow food? (added 12th June 2002)
  660. How can we know that there are other galaxies if we cannot leave ours? (added 12th June 2002)
  661. How does night and day work? (added 12th June 2002)
  662. What colors are visible through an amateur telescope? (added 11th June 2002)
  663. How is the Cepheid yardstick validated? (added 11th June 2002)
  664. What would happen if you went back in time and killed your grandmother? (added 11th June 2002)
  665. Is it possible to measure the temperature of the Sun? (added 11th June 2002)
  666. Did life originate on Earth, or did it come from somewhere else? (added 30th May 2002)
  667. Is the Moon moving away from the Earth? When was this discovered? (added 29th May 2002)
  668. What supernova created the Crab nebula? (added 27th May 2002)
  669. Why can't you see stars during the day? (added 27th May 2002)
  670. Why is twilight short near the equator? (added 27th May 2002)
  671. Why does the Moon look big on the horizon? (added 23rd May 2002)
  672. Which hemisphere has the best view of the Milky Way? (added 23rd May 2002)
  673. How do I tell which planet is which? (added 23rd May 2002)
  674. Why do planets not twinkle? (added 23rd May 2002)
  675. Can you tell time by the Big Dipper? (added 23rd May 2002)
  676. What are the boundaries of the constellations? (added 23rd May 2002)
  677. Why do stars twinkle? (added 23rd May 2002)
  678. What are Altitude and Azimuth? (added 21st May 2002)
  679. What are RA and DEC? (added 21st May 2002)
  680. What equipment do I need for astrophotography? (added 21st May 2002)
  681. What is sidereal time? (added 21st May 2002)
  682. What is a white hole? (added 19th May 2002)
  683. What type of energy does a black hole have? (added 19th May 2002)
  684. Why was Mir burnt up in the atmosphere? (added 15th May 2002)
  685. What class of spiral galaxy is the Milky Way? (added 15th May 2002)
  686. What would happen if we did not have a Moon? (added 15th May 2002)
  687. What would happen to the Earth if an asteroid hit the Moon? (added 15th May 2002)
  688. Is the Moon hollow? (added 15th May 2002)
  689. Why is the shadow on the Moon the shape it is? (added 15th May 2002)
  690. How do rockets move in space? (added 15th May 2002)
  691. Where can I find information on the moons of other planets? (added 15th May 2002)
  692. Where does the name "Moon" come from? (added 15th May 2002)
  693. How many Earths fit into the Sun? (added 15th May 2002)
  694. Does the Sun move around the Milky Way? (added 15th May 2002)
  695. Where does the name "Milky Way" come from? (added 12th May 2002)
  696. Can life exist on the recently discovered extrasolar planets? (added 9th May 2002)
  697. Can a lunar and a solar eclipse happen in the same month? When will this happen next? (added 9th May 2002)
  698. Why do we not have eclipses every month? (added 9th May 2002)
  699. Why are the compositions of comets and asteroids different? (added 9th May 2002)
  700. Why is it called astronomy when all the other sciences end in -ology? (added 7th May 2002)
  701. How was the starting point for the Julian Date system chosen? (added 7th May 2002)
  702. Where can I see Newton's original reflecting telescope? (added 3rd May 2002)
  703. How do we feel heat? (added 3rd May 2002)
  704. How are photons created and destroyed? (added 2nd May 2002)
  705. Can we look back far enough in time to see the Big Bang? (added 2nd May 2002)
  706. Have gravitational waves been proven to exist? (added 2nd May 2002)
  707. Who discovered each planet? (added 1st May 2002)
  708. What month was it when Odysseus saw Orion in 1000BC? (added 1st May 2002)
  709. Was Stonehenge built to mark solar phenomena? (added 1st May 2002)
  710. What is that ring (or rainbow) around the moon? (added 1st May 2002)
  711. How are elements heavier than iron formed? (added 1st May 2002)
  712. How do distant galaxies differ from those nearby? (added 30th April 2002)
  713. Why are there blue shifted galaxies? (added 30th April 2002)
  714. Will we get sucked into the black hole at the center of the Milky Way? (added 30th April 2002)
  715. Why does the SETI project search for radio signals? (added 30th April 2002)
  716. How big is the universe? (added 30th April 2002)
  717. Can we find the place where the Big Bang happened? (added 30th April 2002)
  718. How could galaxies have gotten so far away in only 15 billion years? (added 30th April 2002)
  719. Is cosmic expansion happening on microscopic scales? (added 30th April 2002)
  720. If the universe is 15 billion years old, how can it be larger than 15 billion light years across? (added 30th April 2002)
  721. What is time dilation? (added 30th April 2002)
  722. Do electrons age? (added 30th April 2002)
  723. Can artificial gravity be created in space? (added 30th April 2002)
  724. Can I buy a star? (added 30th April 2002)
  725. How do we know if the universe will keep expanding forever? (added 30th April 2002)
  726. What is the shape of the universe? (added 30th April 2002)
  727. What is the difference between homogeneity and isotropy? (added 30th April 2002)
  728. What's new with the Big Bang? (added 30th April 2002)
  729. What color is Venus? (added 29th April 2002)
  730. Will I be able to see the shadow of the Moon streaking towards me in a total solar eclipse? (added 29th April 2002)
  731. What is the farthest Northern Latitude in which the Magellanic Clouds can be seen? (added 29th April 2002)
  732. What happens to a substance if its speed is more than the speed of light? (added 29th April 2002)
  733. What is a singularity? (added 29th April 2002)
  734. Why does the Earth only see one side of the Moon? (added 29th April 2002)
  735. Is it true that the Sun burns off a billion tons of gas every 5 seconds? (added 29th April 2002)
  736. If the Earth's rotation period is less than 24 hours, why don't our clocks fall out of sync with the Sun? (added 29th April 2002)
  737. How big was the Sun when it first "fired up"? (added 29th April 2002)
  738. How are black holes discovered? (added 29th April 2002)
  739. How long does the supernova stage of a star last? (added 29th April 2002)
  740. What will happen to life on Earth when the Sun becomes a red giant? (added 29th April 2002)
  741. What kind of rock is the moon made of? (added 29th April 2002)
  742. What kind of telescope should I use for astrophotography? (added 29th April 2002)
  743. How do we know the age of the Universe and the Earth? (added 29th April 2002)
  744. How are galaxies named? (added 29th April 2002)
  745. How do you classify galaxies? (added 29th April 2002)
  746. Do galaxies orbit around anything? (added 29th April 2002)
  747. Will the seasons change due to precession? (added 29th April 2002)
  748. How many known galaxies are there? (added 29th April 2002)
  749. Could you tell me about the life cycle of galaxies? (added 29th April 2002)
  750. What is the life cycle of a star? (added 29th April 2002)
  751. How do astronomers measure the brightness of stars? (added 29th April 2002)
  752. Why do constellations look the same after several years even though all the stars are moving? (added 29th April 2002)
  753. Why don't all neutron stars become pulsars? (added 29th April 2002)
  754. What's the difference between astronomy and astrology? (added 29th April 2002)
  755. What is a Cepheid variable? (added 29th April 2002)
  756. Are all stars the same? (added 29th April 2002)
  757. How many stars are there in our Galaxy (Milky Way)? (added 29th April 2002)
  758. What's the difference between astronomy and astrophysics? (added 29th April 2002)
  759. What's the best thing about being an astronomer? (added 29th April 2002)
  760. How much time do astronomers spend looking through telescopes? (added 29th April 2002)
  761. What skills do astronomers need? (added 29th April 2002)
  762. What kinds of jobs do astronomers do? (added 29th April 2002)
  763. What's the best college for astronomy? (added 29th April 2002)
  764. What kind of schooling is necessary to become an astronomer? (added 29th April 2002)
  765. How much money do astronomers make? (added 29th April 2002)
  766. Aren't jobs in astronomy scarce? (added 29th April 2002)
  767. What do I need to do to become an astronomer? (added 29th April 2002)
  768. What direction do planets rotate? (added 29th April 2002)
  769. Why are stars and planets round? (added 29th April 2002)
  770. How does libration allow us to see more than 50% of the Moon? (added 29th April 2002)
  771. Did astronauts really go to the Moon, or is it a hoax? (added 29th April 2002)
  772. How can you tell the difference between single and multiple extrasolar planets? (added 29th April 2002)
  773. What would happen if an impact caused Earth to stop rotating? (added 28th April 2002)
  774. How do I polar align my telescope? (added 28th April 2002)
  775. Why aren't there any green stars? (added 28th April 2002)
  776. How are asteroid compositions and classifications determined? (added 28th April 2002)
  777. How can I tell if the rock I found is a meteorite? (added 28th April 2002)
  778. How do I build a model rocket? (added 28th April 2002)
  779. Can you see satellites? (added 28th April 2002)
  780. Can you hear sounds in space? (added 28th April 2002)
  781. What would happen if you took off your helmet in space? (added 28th April 2002)
  782. Does the shuttle worry about space junk? (added 28th April 2002)
  783. What is a dimension? (added 25th April 2002)
  784. Why do clocks turn in the opposite direction from the Earth and Moon? (added 25th April 2002)
  785. Do you believe in UFOs? (added 25th April 2002)
  786. Do you think it's possible to maintain life on other planets? (added 25th April 2002)
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