REVIEWS
More than a
picture book
The NASA Atlas of the Solar
System
by R Greeley and R Batson
Cambridge University Press
369pp ISBN 0 521 56127 2
£100 hbk
Staggering images from around the
Solar System have been exerting
their fascination for decades now,
yet they have remained for the large
part the domain of specialists. But
the scientific public need no longer
rely on Hollywood’s imagination
for maps of our neighbourhood in
space. The NASA Atlas of the Solar
System provides, in a
large-format volume,
a colour atlas of the
whole Solar System,
including comets and
asteroid belts.
As stated by W
Huntress, Associate
Administrator for
Space Science at
NASA, “For the first
time, [this atlas] draws
together systematic
maps, photographs,
and overviews of the
planets and major
satellites, representing
more than a quarter
century of Solar System exploration.”
This is an understatement. By including
explanations of map
preparation and image
enhancement, the
clever authors have
produced an essential
workbook for students of remote sensing, geography, geology, geophysics, and
astronomy.
The NASA Atlas of
the Solar System is a full-size atlas,
commonly with two-page colour
illustrations and colour sketches.
More than 100 names in the list of
credits attest to the care and effort
that went into the book’s production. Text is double spaced and
continuous, with figures in the margins, rather than interspersed.
The atlas is pitched at an undergraduate level, and should be accessible to secondary school students.
But science buffs of any age will be
riveted to many of the images.
Examples are generally free of technical jargon, and care is taken to
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preserve scale wherever possible.
Necessary jargon and scientific
terms are defined in an appendix,
or illustrated with simple diagrams
and sketches. One logistical drawback is the lack of figure numbers,
although captions can readily be
linked to figures.
The atlas is arranged with an
introductory chapter, a chapter on
the Solar System, then chapters on
each of the planets and their orbiting bodies, moving from Mercury
to Pluto, followed by asteroids and
comets. The introduction itself is
noteworthy for its clear explanations and examples of map projections, preparation, compilation, and
their limitations. A brief nomenclature of geographic place names and
naming protocol answers questions
I have been asked by children and
students since my days as a NASA
Research Fellow. Chapter 2, The
Solar System, commences with the
Sun and the history of the Solar
System, including a beautiful montage of spacecraft imagery of the
planets, as if viewed from the Sun.
Although a relatively small part
of the atlas, the exciting history of
space missions to the solar system is
encapsulated in text and figures. I
was impressed by the credit given
to non-US space exploration, and
the impression that forward directions will require international
collaboration if they are to succeed.
The introduction begins with a
brief history of the Solar System,
followed by a summary, in words
and pictures, of planetary processes.
The key elements of planetary tectonics, surface processes, volcanism,
geological time and methods of age
determination are included,
although I noted a mistake in the
direction of forces creating horsts.
The chapters on the planets are as
varied as the planets themselves,
reflecting our knowledge or ignorance of particular areas. The
images are stunning, and I spent an
hour choosing my favourite photo
from them. Equal area projections
with latitude and longitude references make interplanetary comparisons a joy, rather than an occupation. Perhaps this is
the strongest point of
the atlas – scale and
scope are easily
assessed and accessed.
The gazetteer at the
end contains not only
geographic and page
references, but a geographic and geological
description of the
planetary feature,
including the origin of
its name. Nanedi
Valles, Mars, comes
from the common
name for “planet” in
Lesotho, Africa, but
we are left to surmise
the origin of Wahoo
crater, Mars.
It has been said
many times before that
“a picture speaks a
thousand words”:
these images left me
with just one: spectacular! I thoroughly
enjoyed preparing this
review, and must
admit that this atlas
was a magnet for staff,
students, and teenage
children. I even had to borrow the
book back from a colleague to
complete the review.
In summary, this atlas is a must
for all university libraries, and is
highly recommended for secondary
schools. The imagery and illustrations allow a true appreciation of
the vast distances and scales of
planetary bodies; in this compilation they will enable students to
visualize what we try to teach.
Cindy Ebinger lectures in tectonics
at the University of Leeds and is
currently in the Dept of Geophysics, Stanford University.
An historical
whodunnit
The Comet of 44 BC and
Caesar’s Funeral Games
by John T Ramsay and A Lewis
Licht
1996 Scholar’s Press Atlanta
Georgia 236pp
ISBN 0 7885 0274 3 $17.95 pbk
ISBN 0 7885 0273 5 $27.95 cloth
What do the comets of 1577 and
1618 and comets Halley and HaleBopp have in common? The answer
is that they have all been so famous
that they have merited individual
books. To this illustrious list we
must now add the comet of 44 BC,
a comet that was bright enough to
be seen in broad daylight.
Let us refer to it as Comet Caesar.
This comet is not mentioned in G
W Kronk’s Comets, A Descriptive
Catalog (Enslow 1984) or B G
Marsden and G W Williams’ Catalogue of Cometary Orbits 1996
(IAU), but it does figure in Shakespeare. On the Ides of March
44 BC it purportedly worried Julius
Caesar’s wife Calpurnia so much
that she tried to get her husband to
take a day off from the office:
“When beggars die, there are no
comets seen/The heavens themselves
blaze forth the death of princes.”
In this book, numerous historical
sources are assembled and Roman
observations are compared to observations from other parts of the
world. Unfortunately science was
rather vague in those times. Essentially every one of the Roman
records is based on the same
description of Comet Caesar written
by Gaius Octavian 20 years after
the event, when he casually mentioned how the comet had interfered
with the funeral games (ludi Victoriae Caesaris) held in honour of his
murdered predecessor.
Ramsey, a classicist, and Licht, a
physicist, both at the University of
Chicago, have collaborated to produce an intriguing investigation of
the observations and characteristics
of this comet. The resultant book is
one of those thorough historical
tomes in which the footnotes seem
to be trying to take up more space
than the general text. Within the
scholarly text, however, there lurks
a series of intriguing questions.
When exactly did these games
take place? And where was the
comet in the sky? Ian Gruter suggested that the games started on 23
June/July 1997 Vol 38 Issue 3
September. Edmond Halley thought
(erroneously) that Comet Caesar
was a previous apparition of the
Great Comet of 1680. The Chinese
saw a comet in May and June
44 BC. Did the Romans actually see
the same comet (they did not mention a tail), or was it a supernova?
Were their observations possibly
fictitious? Was it a sign of Caesar’s
apotheosis? Why was this comet
regarded as a propitious omen and
not the more usual baleful one? Did
Etna erupt at the same time? Did
the comet outburst in July 44 BC?
Did it really have an orbital perihelion distance of 0.22 ± 0.05 AU, and
inclination of 110 ± 20°, a longitude
of ascending node at 141 ± 30°, an
argument of perihelion of 17 ± 17°
and a perihelion passage on 25 ± 1
May 44 BC?
Ramsay and Licht have produced
a magnificent piece of interdisciplinary detective work. All the Greek,
Latin, Chinese and Korean sources
are skilfully translated, making it
accessible to a wide scholarly scientific audience. And all the science is
carefully explained, making it
accessible to the classicists.
David W Hughes is the Reader in
Astronomy at the University of
Sheffield.
H Mikuz & B Kambic, Crni Vrh Observatory, Slovenia
REVIEWS
If you missed the glorious sight of
comet Hale-Bopp in April, don’t
panic, it is not too late: the Internet
contains more spectacular images
than you could shake a stick at.
There are excellent Web pages on
this comet from institutions, professionals and amateurs alike, all topical and often updated daily.
Following the suggestions in the
previous issue, I started with Alan
Fitzsimmons’ home page, http://star.
pst.qub.ac.uk/~af/hb/hb.html where
he has posted some spectacular photos (such as the sunset image shown
right), together with camera and
exposure details. In addition, he
details observations of the comet
over the past few years, its predicted
light-curve, and gives information
on how to find it in the sky. There
are also images from the Jakobus
Kapteyn and William Herschel Telescopes at La Palma, together making
an inspiring page for both amateur
and professional photographers.
There are also useful links to comet
pages big and small worldwide.
June/July 1997 Vol 38 Issue 3
A Fitzsimmons
Web wanderings:
in search of
comet Hale-Bopp
The Comet Home Page at
http://encke.jpl.nasa.gov/ is one of
the best, with hundreds of images
from observatories and individuals.
These are well classified, making it
easy to focus on particular topics,
such as jets or the structure of the
tail. There is a wealth of technical
information, charts of the comet’s
path through the skies and wonderful, well-documented images, amateur and professional, including a
spectacular one (shown above) from
Crni Vrh Observatory in Serbia.
The Jet Propulsion Laboratory’s
Hale-Bopp pages at http://
newproducts.jpl.nasa.gov/comet is
a chatty and accessible site,
enlivened with snippets such as
clarification, for those requiring it,
that there is no sign of an alien
spaceship or any other object in the
wake of the comet. A good idea on
this page is the use of press releases
describing findings about the
comet. Good writing that summarizes this exciting science for a general audience is rare, so it’s nice to
see some examples going out to
more people from this page. And
there are of course the usual stunning images, including a wonderful
view of Hale-Bopp and the Manhattan skyline.
A slightly more technical digest
can be found at http://http.hq.eso.
org/comet-hale-bopp/ from the
European Southern Observatory.
This is a valuable and well-organized source of scientific debate.
Prompt updating makes this a good
place to keep on top of the questions raised by the comet’s changing
appearance, giving, for example, a
list of all chemical species detected
at Hale-Bopp so far. And there are
useful facts to astound your friends;
for example, at the start of April,
Hale-Bopp was producing 600 kg
of water per second.
Spectacular images abound here
also, and from a wide range of
wavelengths. Infrared images establishing the composition of grains
from the comet’s nucleus can be
found here, as can images from the
International Ultraviolet Explorer.
But the special feature of this page
is the level of informed comment,
for example on the body of data
represented by the staggering numbers of pictures of the comet. Surely, suggests the page author, someone could find a way to splice
together and utilize this continuous
record of the development of the
tail and coma?
This summary merely scratches
the surface of the huge range of
Web sites on the comet, reflecting
the widespread interest in HaleBopp. As a measure of this fascination, the JPL comet page recorded
1 243 749 visits in one 24 hour
period. As the comet recedes and
the data is digested, I expect these
sites to offer yet more fascinating
information. I shall be watching
with interest. But now I’m going
back to the site with the best name:
the Great Canadian Hairy Star
Party, at http://scienceweb.dao.nrc.
ca/comet.html.
Sue Bowler.
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