Sky & Telescope - March 2024 - 7

I really enjoyed Howard Banich's detailed
observer's guide to M33 in the November
S&T. I'm hoping my Bortle 4 sky will
allow me to try observing some of the
details he pointed out in his wonderful
article using my Celestron C11 SchmidtCassegrain.
His sketches are incredible!
One thing I really appreciate is that
many articles in S&T are regularly aimed
at those of us who call visual astronomy
our passion - I'm so glad for that!
I'm out there with my always-growing
observing list, various binoculars, widefield
4.7-inch refractor, and 11-inch
Schmidt-Cassegrain any chance I get.
It was such a great article, and for
Banich's 33rd at S&T, it was extra fun. It
has got me jonesing for a clear night for
a close look with his sketches.
Nils Walter
Garrison, New York
Howard Banich replies: Thank
you, Nils! I think you have a good
chance of seeing some of M33's details
"
SUBMISSIONS: Write to Sky & Telescope, 1374 Massachusetts Ave., 4th Floor, Cambridge, MA 02138, USA, or email:
letters@skyandtelescope.org. Please limit your comments to 250 words; letters may be edited for brevity and clarity.
75, 50 & 25 YEARS AGO by Roger W. Sinnott
1949
1974
º March 1949
Radar Echoes " Early in the summer
of 1947 the Dominion Observatory
and the National Research
Council, both of Ottawa, commenced
a co-operative program
of meteor observation. . . . The
basic purpose of this investigation
is a detailed correlation of
visual, photographic, and radar
data. . . . The radar equipment has
been operated in the band 30-36
megacycles per second (10.0-8.3
meters wave length). . . .
" To study the relation among
1999
heights determined by the three
methods, detailed computations
have been carried out for the night
of August 10-11, 1948. [We found
that] there is a tendency for the
radar echo to occur near the end
of the visual trail - for the Perseids
at least. "
Meteor experts Peter M. Millman
and D. W. R. McKinley added
that radar held promise for studying
daytime showers.
º March 1974
Cometary Dud " The impression
made by Comet Kohoutek 1973f
depends very much on with whom
you talk. Professional astronomers
are enthusiastic about observations
they obtained that should tell much
about the structure and origins
of comets. . . . [Amateurs] were
rewarded by a beautiful and delicate
object in the evening sky . . . But
the general public wondered what
had happened to the spectacle
promised by the news media. . . .
" [Their disappointment] was
mainly due to overenthusiastic
advance publicity. Last spring, if an
astronomer were asked how bright
Kohoutek would become, a careful
answer would have been: 'Possibly
magnitude -5 to -10, but that will
be at a time when the comet is too
close to the sun to be seen . . .' "
º March 1999
Killer Asteroid " Like finding a
stray bullet at a crime scene,
a researcher believes he has
uncovered a long-sought chunk
of the impactor thought to have
snuffed out 70 percent of the
species of life on Earth 65 million
years ago. . . .
" Geochemist Frank T. Kyte
(University of California, Los
Angeles) has been studying a
core sample from the bottom
of the Pacific Ocean containing
dark clay marking the boundary
of the Cretaceous and Tertiary
periods (the K-T boundary). [This]
clay layer included a 4-millimeterwide
piece of lighter-colored clay.
Upon splitting open the nugget, he
discovered a fossil meteorite. . . .
" Because the ocean-floor
sediments at the K-T boundary
accumulated over perhaps as much
as 500,000 years, there is no way
to prove that this truly is a piece of
the K-T impactor. [But Kyte] largely
discounts the possibilities that the
material is interplanetary dust or
cometary debris. [He] thinks it quite
conceivable that a piece of the
asteroid that struck the Yucatán
Peninsula survived the blast and
landed 9,000 kilometers away. "
sk yand tele scope .o r g * MARCH 2024
7
through your Schmidt-Cassegrain on a
good night. I live in a Bortle 4 area, too,
and have been surprised by what I can
see, but the sky has to be very transparent.
You may even get your best view of
M33's spiral structure with your 4.7-inch
refractor. I agree that S&T does a good job
of presenting articles for visual observers
- as wonderful as imaging is, it isn't for
everyone. I'm looking forward to seeing
M33 again this autumn, too.
Thanks for Participating
Thanks to S&T for publishing my
" Jupiter Deflection Project - Call for
Observations " (S&T: Oct. 2023, p. 6) for
last October's Jupiter conjunction. From
within hours of the digital issue going
live, up until the morning of the event, I
had people signing up. Skill levels ranged
from beginners to professionals, including
programmers. I was hoping for a
wide geographic coverage in case of bad
weather, and it worked: Observing locations
ranged from all across the U.S. to
Europe and even included some remote
telescopes. Some observers were clouded
out, but others were very successful. It
will take a while to process the data, but
I'll send another note when the results
are good enough to demonstrate once
again that Einstein was right!
Here is a link to a video of the event:
skyandtelescope.org/jupiter-deflectionproject-october-2023.
Don
Bruns
San Diego, California
FOR THE RECORD
* In " Messier 33: An Observer's Guide "
(S&T: Nov. 2023, p. 58), the locations of
two targets, U62 and IC 134, are mislabeled.
See https://is.gd/Banich_M33 (at
end) for their correct locations.

http://skyandtelescope.org/jupiter-deflectionproject-october-2023 http://skyandtelescope.org/jupiter-deflectionproject-october-2023 https://www.is.gd/Banich_M33 http://skyandtelescope.org

Sky & Telescope - March 2024

Table of Contents for the Digital Edition of Sky & Telescope - March 2024