I also saw the bright meteor of June 9, with Sam Rua at Chiricahua National Monument. I also noted that it passed downward near Sagittarius. I noted 2 or 3 bright flashes sufficiently bright to make me shut my eyes from the discomfort. I heard no sounds. The color I noted was green. The object seemed to exhibit an elliptical-shaped head and a tail of maybe 5 degrees, although I'm straining my memory re: the tail length. Sam noted a color change. I think he mentioned an orange hue during part of the apparition. ----- Original Message ----- From: Bill Peters <afls@xxxxxxx> To: <az-observing@xxxxxxxxxxxxx> Sent: Monday, June 10, 2002 1:26 AM Subject: [AZ-Observing] Meteoric observations need accurate reporting > > To anyone observing a extremely bright bolide (aka: fireball). > > Most of the reportings of the June 9, 2002 fireball are too vague to be able > to triangulate the trajectory and locate a possible fall zone. > > There is great scientific value in the recovery of observed falls. This > best way for recovery of an observed fall that does not land at your feet is > for compilation of accurate reporting by multiple observers. Even if the > meteor has little chance of recovery or did not even survive entry it is > still possible to compute a rudimentary orbit from accurately reported > sightings and contribute to our understanding of bolides. Scientists are > theorizing that some Earth crossing meteorites travel in similar orbit > families, but it has not yet been confirmed. Of significant interest are > the early June bolides and recovered meteorites. Early June holds the > distinction of having both the most observed and recovered fireballs or > anytime during the entire year. Although there is no indication that this > June 9 bollide landed it still is useful to learn from this event. > > Several pointers in reporting your observations of very bright meteors: no > observer can judge distance nor size of the event, only direction from an > observers location. Therefore give accurate location of observing site and > precise directional information of the travel path of the bolide. There are > three primary observable events in the final flight of a bolide; its entry, > its oblation (explosive disintegration, the big flash sometimes multiple), > and its point of dark body state where visibility ends. It is important to > obtain info on where in the sky the meteor BEGAN, where is oblated > (exploded), and where it ended (reached dark body state). Most observers > only view the final one or two events. Essentially all meteorite falls > reach dark body state before hitting the ground. > > Once a target area is located from distant observers it is very important to > find the closest observers to the fall site. I am not surprised none of the > observers reported any sounds. Likely they were too far away, or else > distracted by what they had seen and their excitement in talking about it. > > Sounds are very important to listen for. Bollide sounds can travel over 50 > miles, but the long distance and time delay are not realized by possible > observer/listeners who are not paying attention or do not associate the > sounds with the observed event. Even the June 7, 1998 Stanfield, AZ Fall > Meteorite people, who were just 8 miles away were surprised, by the sounds > heard 40 seconds later - much later than what one would hear from thunder - > typically heard no more than 20-25 seconds after the strike. There are two > distinct phenomena on bolide sounds: the simultaneous often radio-like > static created in the same way, and the sonic booms of the meteor in flight. > The sonic booms are the key to judging distances. The way to time and > listen for them is begin counting immediately after you've seen the flash > (explosion) until you can look at your watch to continue the count. Cupping > your ears with your hands will greatly enhance your listening ability. You > will need to keep listening for over 4 minutes. Sound travels 1 mile per 5 > seconds. Therefore if you do hear and time sounds you can easily compute > distance. I myself have heard a sonic boom from a military jet on a known > path 45 miles away nearly four minutes after the event. > > Here are some basic questions to report after observing a bolide: > 1 Where were you when you first saw the meteor? (Give observing site, > address,or unique identifying info) > 2 At what point in the flight did you first notice it? > 3 What did you see? > 4 Where did it begin -if observed? > (Give degrees above the horizon, observed beginning point directional > location, background star fields trees, houses, mountains or other markers, > precise direction of travel, repeat for next two questions. Example: it > began 30* above the horizon at the 1 o'clock position from North just to the > right of the tail star in the Big Dipper traveling ESE, it exploded at 70* > above the horizon at the 10:30 position and I followed it until it reached > the 8 oclock position 20 degrees above the horizon. It the backgound I > could see its endpoint was just to the right and above the right secondary > peak of the Table Top Mountian.) > > 5 If is exploded, at what point(s) in the trajectory? > 6 Where did it end? > 7 Did you hear anything? What did you hear? > 8 Were you able to time how long after seeing the event before hearing > it? > 9 How bright was it? Did you see your shadow? > 10 What color was it? Was the color consistant or did it change? > 11 Could you observe a remnant trail after the event? Where did the trail > end? > 12 Who else do you know saw it? Can they be contacted? > > Good reporting from multiple observers from different locations should lead > to plotting a rudimentary orbit and determining a scatter ellipse of a > possible fall search. > > Bill Peters 480-813-4242 > > > > -- > This message is from the AZ-Observing mailing list. See this message's > header if you want info about unsubscribing or the list's archive. > > This is a discussion list. Please send personal inquiries directly to > the message author. In other words, do not use "reply" for personal > messages. Thanks. > -- This message is from the AZ-Observing mailing list. See this message's header if you want info about unsubscribing or the list's archive. This is a discussion list. Please send personal inquiries directly to the message author. In other words, do not use "reply" for personal messages. Thanks.