Ask A Scientist© Astronomy Archive

Author:      hasinoff
Please tell me about the oort cloud.  My student would like to do a science
fair project on the subject and I am looking for reference materials to help
her.

Response #:  1 of 2
Author:      hawley
The Oort Cloud (note: singular tense) is the theoretical region associated
with our solar system where most comets spend most of their time.  This is
possible because most comets have highly elliptical orbits.  Look for a
college undergraduate text book on astronomy.  This may be beyond the level
of a high school student, but a possible project might be to use the orbital
parameters of known reappearing comets to calculate the dimensions of the
Oort Cloud.  It would also be interesting to learn more about Professor
Oort, and how he came up with the idea.

Response #:  2 of 2
Author:      rcwinther
The best write up on the Oort cloud of the astronomy texts I have is in
"Exploration of the Universe" by Abell, Morrison, and Wolff.  Some astrono-
mers believe that in addition to the Oort cloud, there is another reservoir
of comets (the source of "short-period" comets) called the Kuiper belt.  I
consulted the on-line Reader's Guide and found some magazine articles that,
from the abstracts, look promising:
Sky and Telescope  Jan. '93  p. 15,  p. 26-9
Sky and Telescope  Apr. '93  p. 44-5 <-- about Jan Oort
Astronomy          Sept.'92  p. 40-7
Discover           Feb. '91  p. 8