The Sun

The sun is the major source for Space Weather in the solar system. Storms of matter and energy from the sun travel out into space. When Earth intercepts some of this energy, its environment changes suddenly. This can have severe consequences for satellites and astronauts in space, and even cause electrical power blackouts here on Earth. For more information, visit the Human Impacts of Space Weather web site at to learn more about the human and economic consequences of space weather.

  1. Can we ever alter the spectrum of the sun?
  2. How can I pick up solar activity on my short-wave radio?
  3. Why is a magnetic field 'frozen into' the solar wind?
  4. Did ancient peoples really predict solar eclipses?
  5. Are solar magnetic storms expected to be at a high point this year?
  6. Can you use sunspots to figure out the rotation period of the Sun?
  7. Would the solar wind knock a planet off its orbit if the planet didn't have a magnetic field?
  8. Is the sun shrinking 200 miles/year?
  9. How do we know what the inside of the sun is like?
  10. If the solar corona is so hot, why can't we see it?
  11. Is our Sun a member of a star cluster?
  12. How do we know the Sun was not at one time a member of a binary system?
  13. What is the solar wind?
  14. Do all stars produce solar winds?
  15. Exactly where is the Sun during the year in contrast to where astrologers say it is?
  16. How does the solar wind affect the Earth?
  17. How does the solar wind change with time?
  18. What causes the solar wind?
  19. Where does the solar wind occur?
  20. How can astronomers study what happens inside the Sun?
  21. How did the Sun's luminosity change during the first billion years?
  22. When will the Sun stop producing enough light and heat to keep the Earth habitable?
  23. How much has the size of the Sun changed in the last few billion years?
  24. How do we know that the Voyager spacecraft have reached the heliopause?
  25. Can the solar wind be reflected off of the Moon or otherwise re-directed back towards the Earth?
  26. have any pictures of the sun ever been taken from space?
  27. What does the sun look like from the surface of Mars?
  28. What is helioseismology good for?
  29. How was the Sun formed?
  30. What are the major components of the solar wind?
  31. How long does it take light to get out from the inside of the Sun?
  32. Is the solar wind a problem for astronauts?
  33. Is the Sun really shrinking in size?
  34. What does the Sun sound like?
  35. If sunlight is white, why do we call it a yellow star?
  36. If the sun had a white dwarf, what would it be like in our solar system?
  37. How is it possible to know the temperature of the Sun?
  38. What is the farthest likely distance to a companion star to the Sun?
  39. Does nuclear fission also happen inside the Sun?
  40. When and how was the distance to the Sun first determined?
  41. Does our sun orbit something else before it orbits the Milky Way?
  42. Has the solar 'missing neutrino' problem been solved?
  43. Why is it more dangerous to look at the sun during total eclipse than in watching the sun set?
  44. What is solar parallax?
  45. If the Sun's solar wind increased 100 times how would the Sun evolve?
  46. What is the range of light travel times to the Earth from the Sun?
  47. What did people know about the Sun in the 1820s?
  48. What is the predicted solar activity for the next 6 months in 1997?
  49. is the core of the Sun really hotter than its corona and surface?
  50. How fast and far does the solar wind blow?
  51. Does the Sun have any water?
  52. What is a 'solar pillar'?
  53. What is the composition of the Sun?
  54. What will cause the Sun to be brighter in 500 million years and make life impossible on the Earth?
  55. What would happen if the Sun exploded?
  56. What is the true rotation period of the Sun?
  57. How far is the Sun from the center of the Milky Way?
  58. How long will it be before the Sun's expansion makes life on Earth impossible?
  59. How does the Sun's rotation cause sunspots and magnetic field reversals?
  60. Does the Sun make noise as it burns?
  61. What is the Sun's lifetime going to be?
  62. What does the solar wind blow if space is a vacuum?
  63. How does the solar wind work?
  64. If the solar wind can't rearrange the dust on the Moon, why does it blast dust from comets?
  65. How is the solar magnetic field generated?
  66. If gamma rays are produced in the Sun's core and are invisible to the eye, where does sunlight come from?
  67. Is there any absolute proof that the Sun is not a member of a binary star system?
  68. What is the rate of mass loss by the Sun from the solar wind?
  69. Why don't Venus and Mercury transit the Sun every year?

All answers are provided by Dr. Sten Odenwald (NASA/Raytheon)