Sky and Telescope - February 2016 - 8

Letters

ALMAGESTUM NOVUM

Andrew Livingston replies: Or perhaps he's
Helios Panoptes, the all-seeing Sun, since
his telescope points signiﬁcantly in that
direction and he's a central character in
the theories of both Tycho and Copernicus.
Meanwhile, I owe Norman Hugh Redington
an apology: Saint Catherine is indeed a
patron saint of astronomy - at least in the
Greek Orthodox Church.

Messier's Missing Object(s)
In support of Michael A. Covington's article "The Case of the Missing M102" (S&T:
Sept. 2015, p. 34), I used NGC 5866 for
that object when submitting my observations for the Astronomical League's
Messier Club Award in 2006. The site
messier.seds.org/m/ngc5866.html convinced me that this galaxy corresponds to
Messier's 102nd object. The proof is not
without doubt, but, as Covington notes,
replacing "0 Boötis" with "θ Boötis" puts
M102 right where Messier described it.
Lloyd Lashbrook
Plano, Texas

The Eyes Have It
Concerning the identity of the man with
many eyes depicted in Andrew Livingston's article on Riccioli (S&T: May 2015,
p. 27, and Oct. 2015, p. 8), my best guess
comes from having read Greek mythology
as a kid: he's the 100-eyed giant Argus
Panoptes. Perhaps Riccioli cast him as a
stargazer due to his omniscience?
David Dickinson
Hudson, Florida

75, 50 & 25 Years Ago

Roger W. Sinnott

February 1941
What's Your Sign? "The
public interest in astrology has grown rapidly
during the past decade.
This increasing popular
appeal is in no small
measure due to the
general misapprehension that exists in the minds of many about the
standing of astrology as a 'science.' . . . There
is hardly an astronomer who has not been
approached on more than one occasion with a
request for the preparation of a horoscope. . . .
"Hollywood appears to be a veritable astrologers' paradise, and in a quieter way Wall Street
has proved a fertile ﬁeld for astrological activity.
Thus it is quite apparent that the inﬂuence of
astrology is by no means limited to persons with
salaries in lower income brackets. . . ."
Along with this report, "Scientists Denounce
Astrology," editors Charles and Helen Federer
railed against astrology in an accompanying
editorial. Yet, as recently as 2005, a Gallup poll
found that fully 25% of Americans believe in
"astrology, or that the position of the stars and
planets can aﬀect people's lives."

After reading "The Case of the Missing
M102," I began to consider the possibility that NGC 581 is not M103. Instead, I
believe that NGC 663 might be the object
that Pierre Méchain, who contributed 28
objects to the Messier list, observed and
recorded as "A cluster of stars between
Epsilon and Delta of the leg of Cassiopeia." NGC 581 is about a third of the way
between Delta and Epsilon and closer to
Delta, whereas NGC 663 is almost at the
midpoint, though slightly below the line
between these two stars.
Moreover, NGC 663 gives the appearance, especially in binoculars, of a round,
comet-like object. I can see it in my 10×50
binoculars as a diﬀ use glow, and it's
easier to spot than NGC 581. John Herschel describes it as "Bright cluster, pretty
large; round and rich, with stars 10 and
11 mag." But NGC 581 is not round. So in
my opinion it ﬁts neither Méchain's position nor Herschel's description of M103.
Tom Reiland
Pittsburgh, Pennsylvania

Februar y 2016 sky & telescope

February 1966
Martian Water "Last
summer, when the
Mariner 4 photographs of
Mars were ﬁrst studied,
it was quickly realized
that the planet has about
as many craters, area for
area, as the moon. This
fact led [many] to speculate that the Martian
surface is about as old as the moon's - two to
ﬁve billion years. . . .
"Three later investigations [indicate] the
Martian surface may be much younger. . . . E.
Anders (University of Chicago) and J. R. Arnold
[have] deduced statistically that Mars should
experience about 25 times as many asteroid
impacts, area for area, as the moon. [They]
conclude the surface of Mars is only a sixth
as old as the moon's. . . . 'In any event, the
crater density on Mars no longer precludes
the possibility that liquid water and a denser
atmosphere were present on Mars during the
ﬁrst 3.5 billion years of its history.'"
How surprised they'd be at NASA's ﬁnding,
announced last September, that liquid water
exists on Mars now (S&T: Jan. 2016, p. 14).

February 1991
Sundown, Exactly
"When does the last
gleam of sunlight
disappear? . . . To ﬁnd
out, Bradley E. Schaefer (NASA-Goddard
Space Flight Center)
and William Liller (Isaac
Newton Institute, Santiago, Chile) collected 144
measurements of the low Sun. They adjusted
each one to establish what the actual refraction would have been on the horizon for an
observer at sea level [and ﬁnd the spread to
be] 0°.64 at the 95-percent conﬁdence level.
This variance is much larger than has been
previously assumed by nearly all the world's
astronomers. . . .
"[This u]npredictable refraction casts
doubt on some claims by archaeoastronomers
that ancient stone walls and monuments are
aligned with the rising and setting directions
of speciﬁc celestial objects. This is so because,
in general, objects approach the horizon
obliquely. [Examples include] the claims by the
late Alexander Thom that British megalithic
sites were accurate lunar observatories. . . ."

http://messier.seds.org/m/ngc5866.html

Sky and Telescope - February 2016

Table of Contents for the Digital Edition of Sky and Telescope - February 2016