Customer Reviews

Venus Revealed: A New Look Below The Clouds Of Our Mysterious Twin Planet

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Anyone that wonders why humans should continue to invest in space exploration--especially important at this time of tragedy with the Columbia mission--will find many answers in this excellent book. Grinspoon is one of those rare writers that enthralls us with the mystery and wonder of science, while at the same time not shying away from, or diminishing the complexities of scientific discovery. He describes with clarity why studies of other planets are important endeavors in their own right, as well as for our continued understanding of our own planet Earth.

All readers will gain an appreciation from Grinspoon for scientific discovery: how it builds with improving data from insights that at first seem remote and uncertain into solid foundations for better understanding of issues such as global warming on earth. Volcanology, plate tectonics, acid rain, and planetary climatology are all discussed in detail, as well as the more esoteric phenomena of planet formation and extra-terrestrial life. While the later topics might be argued as to their importance with regard to current problems on our planet, Grinspoon makes excellent connections for studies of the former issues on Venus, and their impact to our knowledge of our own home planet. Anything that significantly improves our understanding of global warming, plate tectonics (earthquakes), etc., is worth a significant and continuing investment. Venus Revealed is great book in many respects: lack of a bibliography is the only fault worth mentioning. (And I, for one, loved the often hilarious footnotes!) Highly recommended.

Besides a excellent historical and scientifical synthesis of the Venusian system, this book does a good job at comparing the three main terrestrial planets, from the astronomical, physical, geological, atmospheric, etc. point of views. This is very refreshing because Venus is often overlooked in most books, that usually focus more on the binary comparison of Mars vs the Earth, and, in many ways, Terra is actually closer to Venus than Mars.

The text itself is clear, accurate and very entertaining to read (especially the footnotes!). Everything is based on scientific facts, except the last chapter, that digresses a little too much from the main subject, but it's ok.

Venus Revealed by David Grinspoon is one of the best popular-level astronomy books of the 1990s. It is full of substantial information, yet is entertaining and suspenseful. In this regard, it resembles books such as Black Holes and Time Warps by Kip Thorne; The Alchemy of the Heavens by Ken Croswell; and Lonely Hearts of the Cosmos by Dennis Overbye. Venus Revealed traces astronomers' knowledge of the planet Venus--from ancient times, when it was merely a beautiful object in the morning or evening sky, to the era of telescopic observations, which gave rise to fanciful speculations about life, and finally to the modern era of spacecraft, which revealed the true nature of Venus: a dry, torrid world with an atmosphere 90 times thicker than Earth's. Two minor complaints about the book: the numerous footnotes are often silly, and the book lacks a bibliography. Venus Revealed is definitely a lot more appealing than its inhospitable subject.

_Venus Revealed_ by David Harry Grinspoon is a well-written, witty, thoroughly researched book on our nearest planetary neighbor, the planet Venus, often thought of as Earth's twin due to its roughly same size and mass. Grinspoon covered the history of human perception of the planet, the observation of Venus by scientists from the ground through the centuries, what the amateur astronomer can see and learn about the planet, the saga of the numerous probes to orbit the planet as well as it enter its atmosphere and even land on its surface, current understandings of the atmosphere and geology of Venus, and speculations on whether or not Venus has or had life and the future of human exploration of the planet. There are two inserts in the book, one a color insert that included a color image of the surface of Venus made by the Soviet _Venera 13_ lander in March 1982 as well as several global and regional topographic maps made by the _Pioneer Venus Orbiter_ and _Magellan_, and a black and white insert which included more Soviet lander images of the ground of Venus as well as numerous close-ups taken by _Magellan_ of a wide variety of Venusian surface features. In the text of the book itself I really liked the various diagrams included, including schematics of the sulfur cycle on Venus and a diagram of typical cloud structure. _Magellan_ images are dominant in the book, an extraordinary space probe that peeled back the "bright, unyielding clouds" with "gentle radar fingers," revealing massive amounts of new information for Venus scientists to ponder and debate over.

Venus has long attracted human attention, as it is the brightest object in the night sky after the full moon. Though the planet was noticed by virtually every human culture, no civilization paid it more mind than the Classic Maya (A.D. 300-900). They felt they owed their very existence to Venus (whom they called Kukulcan) - a debt that they paid back in human sacrifices - and based their entire calendar on the 260-day Venus appearance interval. Mayan astronomers were able to chart the appearance, disappearance, and reappearance of Venus in the night skies with incredible accuracy, so much that the Mayan Venus Calendar has an error of only two hours in five hundred years of elapsed time.

The "solid citadel of clouds" that protected Venus from observation made it into a "tabula rasa," a blank slate that was inscribed by the wishes and dreams of observers for centuries. Grinspoon documented the many speculations about Venus being a swamp or ocean world, referencing both the serious speculations of astronomers such as Percival Lowell and the flights of fancy of popular literature and film. So little was known about the planet that even its rate of rotation wasn't resolved until 1962, when Earth-based radar images established that one day on Venus equaled 117 Earth days (and that it rotated in a backward or retrograde direction, with the sun rising in the west and setting in the east). Passive radio observations in 1956 that showed the planet emitting massive amounts of microwave radiation lead to the first real understanding of just how hot Venus was, as researchers began to infer that this was heat radiation from the surface, eventually establishing the surface temperature at 900 degrees Fahrenheit (so hot that an observer on the Venusian surface at night could see thanks to the glowing of the red-hot ground).

I enjoyed his coverage of the Venusian atmosphere the most of anything in the book. Though the planet-wide cloud cover looks basically bright and featureless even from orbit, images taken with ultraviolet filters have revealed that the atmosphere is dynamic and volatile, an intricate and complex swirl of high-contrast, fast-moving tiny splotches and huge, planet-wide streaks. The identity of this material, so dark in the ultraviolet portion of the spectrum that its it responsible for absorbing nearly half the solar energy received by Venus, is still unknown and is simply called the unknown ultraviolet absorber. Its existence though has allowed scientists to study and model patterns of atmospheric circulation, an atmosphere that at the upper levels circles the planet at 200 miles per hour, circling the planet in four days (dubbed superrotation), while at the same time is virtually motionless at the surface. Explaining this phenomenon has presented another major challenge offered us by Venus, one not yet answered.

The atmosphere is unlike anything seen on Earth; immense cloud banks of sulfur dioxide and sulfuric acid cover the planet, not very dense and relatively transparent but incredibly vast, towering up to an altitude of 44 miles from the cloud base at 33 miles. They are concentrated into three discrete layers - each layer with a different mixture of droplet sizes - and separated by relatively clear air between. The nature of the droplets in the lowest cloud layer (called Mode 3 droplets) is uncertain, as they are not spherical in shape, may be crystalline, and appear to contain far more chlorine than sulfur (as well as perhaps other substances).

Grinspoon gave the reader a tour of the surface, from the "continents" of Africa-sized Aphrodite Terra along the equator and Australia-sized Ishtar Terra near the north pole to the wide plains to the great variety of volcanoes on the planet, some of which are probably active. Volcanic landforms cover some 90% of the surface, ranging in size from small shield volcanoes (often less than 12 miles across), so numerous that they gather in clusters of a hundred or so in immense shield fields, to odd six to forty mile across pancake dome volcanoes to still larger ones. Many features appear unique to Venus, such as ticks (volcanoes with flanks scalloped by landslides such that the ridges appear to be the jutting legs of an insect), arachnoids (volcanic domes surrounded by spider-web like patterns of fractures and ridges), and anemonae (volcanoes with petal-like lava flows extending outward from them). Other features include the odd circular coronae and intensely deformed areas called tessera.

I loved reading this book! It describes the cultural, historical and scientific aspects of Venus. For instance, it discusses the significance that ancient cultures placed on Venus (the brightest planet when visible). It also discusses perceptions (and some speculation) that people have had of Venus at various times in history. Then it discusses in detail the scientific discoveries of Venus, by radar and spacecraft. It discusses the politics and development of radar and spacecraft, as well as the actual scientific discoveries made at different times. It is also very fascinating to read about the surface and atmosphere and properties of Venus. It is also interesting how the author compares Venus to Earth in these areas. Although it is obvious that Venus would be a very hostile planet to visit, it is indeed a very fascinating planet to study. In terms of land features, I think that the author points out that Venus is actually similar to Earth in many ways (though also with some of its own characteristics). I highly recommend this book for anyone who is interested in the planet Venus in particular, or in the solar system in general.

Venus Revealed is a very well written book covering a wide variety of topics on Venus. I would recommend this to anyone with more than a passing interest in the planet. Grinspoon is an all too rare author who can provide enough scientific detail to be informative in a book that is a pleasure to read. I appreciated his wit and writing style. Astronomy books are my favorite subjects, but too many of them are so dry that is takes some effort to get through them. Dr. Grinspoon, please don't stop with this one book.

Books like these let the public participate in science data gathered and analyzed by NASA. Here the author has simply and clearly presented the known facts about Venus (and it is quite a revelation at times). Do read it - and participate in planetary exploration, from your arm chair

David Grinspoon weaves a captivating story of the Human race's 6000-year fascination with our "sister" planet. Speckled with humorous anecdotes from his own professional experience with the recent Magellan mission, Dr. Grinspoon gives the reader a vivid picture not only of the planet, but of the scientific methods that exposed and the setbacks that continue to mask the details of Venus. I was particularly intrigued by his connection between the orbital rates of Venus and the Earth (5:8 ratio) and African drumming rhythms.

The book appears to be written for the reader with little or no science background. I found it peppered with just enough science to validate many of the theories or assertions Dr. Grinspoon and his contemporaries make. As an Earthbound geographer, I especially enjoyed his virtual tour of the planet's topographic features.

A full set of color and black-and-white plates is included and referenced in the text. Many diagrams and figures help clarify some of the more technical points in the book. I wish I could have taken an astronomy class from this not-too-serious comparative planetologist.

This book is an excellent read for anyone whose imagination is not stuck on Earth.

I just finished Venus Revealed and am very happy that I took the time to read it. The writing is fresh, the science (though appropriately "lite") is absolutely fascinating. Grinspoon is at his very best as he pushes his readers to accept wider possible definitions of life.

The only major frustration for me was his refusal to reconcile two positions seemingly in conflict: One, that atmospheric systems are mind-numbingly complex, far beyond the capabilities of the most powerful supercomputers to model. And two, that we're definitely changing the composition of our atmosphere as a result of our industrial activities, and that this is causing global warming, and that global warming is bad.

If the atmosphere (and, as I now understand it, the entire globe, above, on, and below the surface) is such a magical, complex machine, how has anybody determined that we're causing global warming?

The truth is that there is no consensus on global warming, at least not yet. Waiting until irrefutable proof presents itself may indeed be foolish, but it is equally (and perhaps more) foolish to rush into the kind of rapid de-industrialization Grinspoon seems to favor, with no disregard for the economic (and long-term environmental) consequences.

Venus may indeed act as a warning against rampant greenhouse gas emission, but as Grinspoon himself points out elsewhere in his book, it may not

I really enjoyed this overview of our sister planet! Despite his background as a planetologist and university professor, Grinspoon writes for the layman with a freshness and spirit that is rare in non-fiction astronomy books. He first takes us through an extensive history of our discoveries and past theories on Venus, then reveals the major findings of the Magellan mission which laid bare the planet's high-level topography. Towards the end Grinspoon presents a couple bold suggestions as food for thought, e.g. the possibility that life currently exists on Venus and also ideas for terraforming the planet!

I especially enjoyed the virtual tour of Venus as well as the descriptions of what it would be like to spend a day and night on Venus, assuming you could survive the extreme heat and crushing pressure. Did you know that it never gets totally dark on the ground, because even at night the rocks are so hot that they glow red??!

The footnotes didn't bother me too much; in fact, I rather appreciated Grinspoon's sense of humor and chuckled at a few of them. One thing that did annoy me was Grinspoon's repeated pessimistic assertions that we humans are wreaking havoc on Earth through global warming, ozone depletion, acid rain, pollution, blah blah. The fact is, it's kind of ludicrous to suggest that the Earth's overall "health" is being affected at all by us. There is no proof of this whatsoever. We may be making things worse for ourselves in the long run, but the Earth is so massive that there's really nothing we can do to hurt it.

Anyway, I've read a few books on the planets and this is the best so far! Just the right blend of science and non-technical discussion to appeal to the layman and the amateur astronomer both.