Thanks to some high-tech videography, researchers at last
have meteor images detailed enough to probe the insides of shooting
stars. The results were presented at a meeting of the American Geophysical
Union earlier in the month.
Hans Stenbaek-Nielsen (University of Alaska, Fairbanks)
captured the meteors on video as part of NASA/Ames Research Center's
Aircraft Campaign (MAC). His camera can take video at a rate of
1,000 frames per second. The instrument was originally used to study
fleeting columns of light sometimes seen above massive thunderstorms.
Stationed at Poker Flat Research Range in Alaska, Nielsen
pointed the camera skyward and spent the night of November 17-18 watching
a video monitor that displayed only a 6°-square field. When he saw
a Leonid cross the field, he stopped the recording and manually saved
the hundreds of images. "I managed to save three good meteors," Nielsen
says. "I did see more, but it was rather tiring observational circumstances."
Nielsen's video clearly shows how the initial pinpoint
glow of the heating meteoroid quickly develops a bow shock and a tail.
Peter Jenniskens (SETI Institute) explains, "Our images for the first
time confirm that most meteor light comes from a bright plasma just
behind the meteoroid."