157 FAQs about Asteroids, Meteors and Comets (The Astronomy Cafe )

Basic Facts: NASA/NSSDC Fact Sheet, Near Earth Orbit Asteroids,Comets

Orbits and Discoveries: IAU Minor Planet Center , Trans-Neptunian Bodies

Pictures: Galileo Pictures,NEAR Pictures,Comet Images,Hubble Space Telescope

Impact Hazards and Extinctions: NASA/Ames Research Center

Comets - General

  1. How big do comets get?
  2. How do astronomers compute the orbit of a comet so rapidly?
  3. Where on the web can I find out about comets?
  4. Why do some comets have two tails?
  5. Do comets have random orbits or do they follow the ecliptic plane too?
  6. Where in the Milky Way do comets captured in the Oort Cloud originate?
  7. When astronomers say there are trillions of comets beyond the orbit of Pluto, are they still considered a part of our solar system?
  8. Can a comet be larger than the Sun?
  9. Where can I get a list of all the known naked-eye comets?
  10. What is the difference between the Kuiper Cloud and the Oort Cloud?
  11. Would a comet sample return be more useful than in situ surface measurements?
  12. How fast do comets move?
  13. Where do short-period comets come from?
  14. How are comet masses determined?
  15. Will there be a NASA space probe sent to a comet in 1999?
  16. What is a comet?
  17. Why don't comets get captured by planets when they come close?
  18. How do astronomers predict the paths of comets?
  19. Do comet tails point in the same direction as seen from all of the planets?
  20. Why don't the ices in comets just sublimate away?
  21. How are comets formed?
  22. Why is the light curve for new long-period comets different than for old ones?
  23. Is it true the Earth passes through the tail of Halley's Comet in 1910?
  24. How do passing stars shake loose 15-20 comets a year into the inner solar system?
  25. How fast do the nuclei of comets rotate?
  26. Who should I contact if I find a new comet or nova?
  27. What is the difference between an asteroid, a comet and a meteorite?
  28. How do you name a comet?
  29. How fast do comets move?
  30. Why are comets sometimes fainter their first time around the Sun than in subsequent passes?
  31. Can you 'simulate' a comets nucleus in the laboratory?
  32. What is the brightest comet ever seen from the earth?
  33. How do you calculate the orbit of a comet from the Earth?

 

Specific Ones:

  1. Is it a conspiracy that no major observatories have photographed Hale-Bopp since October 1996?
  2. What causes the rings and radial features in Comet Hale-Bopp?
  3. What would the surface of Hale-Bopp look like up close?
  4. Will Earth pass through the tail of Comet Hale-Bopp?
  5. Will Hale-Bopp be visible from Botswana between March 23 and April 6?
  6. How do I interpret the diagrams of the Hale-Bopp comet motion in the sky?
  7. Could you say something about the 1997 comet Hale-Bopp?
  8. Could you say something about the Hubble photo of the comet Haley/Bopp?
  9. How many times in Earth's history has Halleys Comet appeared?
  10. Are there any pictures of Hyakutake after perihelion?
  11. Where can I get more information about looking for Comet Hyakutake in March 1996?
  12. Was anything peculiar seen in the tail of Comet Hyakutake?
  13. Is Comet Chiron currently breaking up as is claimed on the Internet?
  14. I saw a bright comet in 1959-1962. Any ideas which one it might have been?
  15. What is the name of the spectacular comet seen in the mid 1970's?
  16. When was the last time we had two bright comets in the same year?
  17. Exactly when will a comet be visible to the naked eye in 1996?
  18. Is Hale-Bopp a periodic comet?
  19. Where can I get a photo of Comet Hyakutake?
  20. Can you say anything about comet P/Wild 2?
  21. Why does Comet Hale-Bopp follow a closed loop on the sky during some days?
  22. How fast is Comet Hale-Bopp moving through space?
  23. Why are there so many estimates for the orbital period of Comet Hale-Bopp?
  24. Would Comet Hale-Bopp be visible from Antarctica in February, 1997?
  25. Where should we look for Comet Hale-Bopp on April 5 at a latitude of +35.5 degrees?
  26. How slow will comet Hale-Bopp be traveling when it is farthest from the Sun?
  27. Has anything weird been seen near Comet Hale-Bopp in the last week?
  28. Have other comets been seen that are bigger than Hale-Bopp?
  29. What is the date of the closest passage to Earth of Comet Hale-Bopp?
  30. Where can I get more information about Comet Hale-Bopp?
  31. Where can I find Comet Hale-Bopp?
  32. When will Hale-Bopp be visible from Australia?
  33. Did Halley's Comet recently get bumped by Jupiter so that it will not return in 60 years?
  34. Why was Halley's Comet so disappointing in 1986?
  35. What makes Halley's Comet stay in the same orbit around the Sun?
  36. Did Mark Twain (1835-1910) really get born and die during the apparitions of Halley's Comet?
  37. When will Halley's comet return?
  38. How do astronomers know that Comet Hyakutake has been around the Sun before?
  39. Could Hyakutake and Kohoutek have been 'interstellar comets'?
  40. Why do some comets emit gas and dust even when they are far from the Sun?
  41. Can you tell me anything about the 1997 comet Boethin?
  42. Will Comet Swift-Tuttle collide with the Earth in 4000 AD?
  43. What two comets were visible around 729 AD?
  44. What was the bright comet I saw between 1970 and 1973?
  45. What can you tell me about Comet Arend-Roland?
  46. Can you tell me something about Comet Myrkos?
  47. I saw a bright comet between 1966 and 1972 in the early morning sky. Can you tell me what its name was?
  48. What comets were visible to the naked eye in the late 1950's?
  49. Was there a bright comet seen in 1965?
  50. Where there any naked-eye comets seen between 1947 and 1952?

 

Asteroids

  1. Does the moon of Ida orbit it or just follow in a parallel orbit?
  2. Will the asteroid 1981 Midas collide with the Earth in the 22nd century?
  3. How did asteroid Ida end up with a companion moonlet?
  4. Why was Clementine 2 killed by Congress?
  5. How do asteroid orbits change and can they be simulated in a computer?
  6. Can you recommend any books about asteroids that deal with 'aerophysics'?
  7. Can an asteroid have an atmosphere?
  8. Is the Pentagon planning to shoot down an asteroid soon?

 

Meteors

  1. Will the 1999 Leonid Meteor Shower be spectacular from Egypt?
  2. How do you tell if a rock is a meteorite?
  3. When is the best time for viewing the Geminids this year?
  4. Will there be a major-league meteor shower in 1999?
  5. If I were to see a fireball in the sky, who should I report it to?
  6. What week in August will be best for observing the Perseid Meteor Shower?
  7. Do any meteorites come from outside the solar system?
  8. Can you tell me anything about meteor ablation?
  9. When are you most likely to see meteorites?
  10. Has anyone ever been hit by a meteor?
  11. Will there be a big meteor shower next December because of Hale-Bopp?
  12. How big are the particles we call 'Shooting Stars'?
  13. Why do some meteors produce smoke trails and others not?
  14. If I hear a sonic boom soon after seeing a fireball, how close could it have impacted to where I was standing?
  15. Why do the Earth and Perseids only collide once a year?
  16. How do meteorites form in space?
  17. Can you build an electronic meteor detector?
  18. In August, 1972 a meteor streaked across the sky from Utah to Alberta. Will it be coming back in 1997?
  19. How far apart can two people be and still see the same meteor shower?
  20. Were there any meteor storms in the years 1936, 46, 56, 66, 76 and 86?
  21. If meteors burn up in the Earth's atmosphere, where do they keep coming from?
  22. Is a meteor an exploding piece from a supernova?
  23. Which meteor shower is called the 'Tears of St. Lawrence' and why?
  24. How old is the Murchison Meteorite?
  25. How many meteors enter the Earth's atmosphere every day?
  26. What are fireballs and bolides, and how often can you see them?
  27. I noticed a bright fireball streaking across the sky while looking at the Comet Hyakutake. What was it?
  28. What does an impact created from a small meteor look like?
  29. What is the difference between an asteroid and a meteorite?
  30. Is there a schedule of upcoming meteor showers specifically for various areas of the country?
  31. When will the next big meteor impact happen?
  32. I saw something spectacular in the sky on November 17. Was it a meteor?

 

Impacts

  1. Did the Earth almost get hit by an asteroid on March 23, 1989?
  2. Could Comet Shoemaker-Levy 9 have done more damage to Jupiter if Jupiter had been solid?
  3. Where exactly did the Tunguska Impact occur in 1909?
  4. Is there an asteroid that will hit the Earth in the year 2003?
  5. What would the Cretaceous Impactor have looked like from the ground?
  6. Could an unusual isolated rock with odd markings found in a field in Illinois be a meteorite?
  7. Did the Yukatan Impact really kill the dinosaurs, and when will the next one happen?
  8. Is a program for spotting near Earth asteroids and comets really necessary?
  9. What would a scale model of the closest comet passes to the Earth look like?
  10. Which comet has come closest to the Earth?
  11. Would an asteroid cause less damage striking the ocean?
  12. How can an ordinary citizen prod NASA to search for asteroids likely to strike the Earth?
  13. What happens to a meteor when it hits the ground?
  14. I found an object with a metal detector that looks like a meteorite but is non magnetic. What are the chances?
  15. Is the Earth about to crash into the asteroid belt?
  16. I have heard that Comet Hale-Bopp is passing through Europe in March-April. Where should I go to see it?
  17. Was the Tunguska Impact related to anti-matter?
  18. How can an asteroid make a crater on Jupiter when it has no solid surface?
  19. Is there an impact crater near 77N and 108W?
  20. Will a rogue comet or asteroid hit Earth in the next 50 years?
  21. Could an asteroid strike the Earth with little warning?
  22. How rapidly does dust accumulate on the surface of the Moon?
  23. Can a gigantic comets magnetism cause the Earth's poles to shift?
  24. How much notice would we get from a asteroid like the one that hit Earth 65 million years ago?
  25. Will Halley's Comet ever strike the Earth?
  26. Could a comet impact on Jupiter trigger thermonuclear fusion in its atmosphere?
  27. Could a laser beam be used to deflect an asteroid or comet?
  28. What would happen if a large object hit the Earth?
  29. How should a near Earth asteroid be deflected?
  30. Will an asteroid come close to the Earth in 1999?
  31. How could we protect the Earth against a deadly comet impact?
  32. Is the Earth in the way of any comets?
  33. If a comet was about to strike a heavily populated area, would the authorities try to hush it up to avoid panic?
  34. Will the mid-western states of the USA be hit by a comet on April 7, 1996?

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