The Most Exceptional Textbook This Side of the Galaxy!
11/27/2007
I love this book! I don't even read text books very often, but this one is one of the most fun text books I've ever read--the fourth edition of "The Essential Cosmic Perspective." Perhaps I say this because I like Astronomy. I've never taken the course before, so this is really the only college text book in this subject I've looked at. Still, everything in here is interesting.
It has been updated with the most recent expansions with two notable points. It contains the most recent alterations of language by the International Astronomical Union (IAU). Did you know that Pluto isn't a planet? It's actually a comet! In August of 2006, the IAU changed the definition of planet to account for the differences of the planet Pluto, an object whose composition recently discovered is essentially the same as a comet from the belt of comets just outside of the Solar system: called "the Kuiper belt (pronounced like "viper," but with a K. In 2006, the IAU changed the designation of Pluto to a new category of Solar body: the dwarf planet.
Dwarf planets are not planets, as the definition of a planet now has a finer meaning, changed by the IAU. Planet designations are based on composition and size: the inner four planets--Mercury, Venus, Earth, and Mars--are referred to as "terrestrial planets," because their compositions are made up mostly of metal and rock, they're all about the same size, and they have two moons or less. Asteroids also have the composition of rock and metal, and so the belt of asteroids lying just outside of Mars gives an interesting connotation about our system which I will explain soon. Then, the four outer planets--Jupiter, Saturn, Uranus, and Neptune--are called "Jovian planets," meaning "Jupiter-like," because their compositions are mostly gaseous, and because of their sizes: "gas giants." These Jovian, gas giants are several times the mass and diameter of the terrestrial planets, and so their sizes make them considerable to the system. What sets these solar bodies apart the most is THE WAY THEY WERE FORMED which accounts for their composition differences, and therefore the asteroid belt is the boundary line between the inner-terrestrial and outer-Jovian planets of the Solar system.
Every Solar body with an orbit on a somewhat-similar elliptical plane and beyond Neptune is a comet of the Kuiper belt. Although Uranus and Neptune also have essentially a similar gaseous composition as comets like Pluto, the main difference is Pluto has a radius of about 1000 kilometers. Anything that small is considered to be a comet, and, because the comets of the Kuiper belt are usually very small, Pluto resembles them more than a planet, as it is much smaller than even Earth's Moon. Pluto's mass is about 18 percent that of the Moon.
Remember the tenth planet, "Planet X?" Planet X, the tenth planet, was known as "Planet X" because scientists thought that, because it was so small and had the composition of a comet, that these were fundamental differences between comets and planets of the solar system. They felt that, if every newly-discovered comet of the Kuiper belt orbiting the Sun could be called a planet because it revolved around the Sun, our new computerized telescopes would be discovering planets quite frequently; comets, no matter how small they are, would be called "planets," by old definitions. That's why these new definitions are in place now. Pluto has enjoyed the stature of a planet for about 75 years since its discovery, but now that designation is over.
Additionally, the Jovian worlds are known for their multiple moons. Pluto has a moon, but, because its center-of-gravity lies outside of its moon Charon, both Pluto and Charon should actually be referred to as "binary planets," or more correctly "binary dwarf planets" by IAU's new definition--or rather a "binary system of dwarf planets." A planet and a dwarf planet are separate categories of solar bodies and not the same.
Incidentally, speaking of the Moon, the Moon is thought to have been a planet that, at one time, moved around the Sun. Scientists think this because of the size which is roughly the same as Mercury, a terrestrial composition, and it has a similarly substantial amount of gravity. It theoretically took an orbit around the Earth after they collided based on the attractions of their gravity, after which the Moon started orbiting around the Earth. The Moon is also similar to Mercury in that neither of these bodies maintain any atmosphere.
If you hate Al Gore, well--guess what--the same charts used in Al Gore's film "An Inconvenient Truth" are in this book: a major subsection of one of the chapters. This may be a point of either hostility or remorse for those Americans who were comforted by the anti-Gore beliefs of "the Flat World Society": apparently, some scientists think Al Gore actually has facts within his determinations. This book also states the reasons for these conclusions and relates them to a runaway greenhouse effect. If anyone needs an explanation of why people should be concerned, this is as pedestrian as it comes.
Although Venus is thought to be Earth's sister planet, there is nothing there to comfort any human. It has clouds of battery acid! Until 2006, no one could even see through its thick atmosphere due to an extreme greenhouse effect, and in the past only a form of radio technology could view the planet only slightly. In 2006, the European Space Agency (ESA) landed an unmanned spacecraft there to take pictures and send back data about the surface. The "Venus Express" lander, a specially-made craft designed to withstand Venus' harsh atmosphere, lasted for only about an hour on the surface, then corroded into uselessness and dissolved from the extremities of the atmosphere there. You see, there is no water or oxygen on Venus: the extreme greenhouse effect would've caused its oceans to evaporate into space. The atmosphere on Venus is so thick, the pressure at its surface translates to the pressure of one mile beneath the surface of one of Earth's oceans. This book refers to Venus' surface as resembling "a traditional view of hell" (144).
More importantly, although Mercury orbits the Sun at half the distance as Venus, Mercury's surface temperatures are substantially lower than Venus'. This sounds counter intuitive, and it is. But, the reason for it is the extreme greenhouse effect on Venus. And so, although Venus is twice as far from the Sun, it is MUCH hotter there than on Mercury! While Mercury's temperature goes back-and-forth between 700 kelvins (K) in the day and 100 K at night, Venus has a constant average temperature of 740 K (880-degrees Fahrenheit) all the time!
All this information is located within this book. The writing all seems very well put. The glossary has all the terms located in the chapter questions sections, so students should have an easy time finding anything. The chapter information, as it is introduced, is labeled nicely in easy-to-read bold upon its introduction, so eyes can quickly move right to the place where to find that information. The index is large and covers anything I would want to know. It has beautiful photos, images, and tables, in color of course. Many of these shots are brand-new images from off-earth, satellite telescopes and unmanned space vehicles. Of course, I have some doubt about the context of a few of the pictures, but there's surely nothing missing that NASA or other space agencies have allowed to be released: the book is up-to-date.
The book comes with interactive things like on-line supplements and a CD-Rom. The CD-Rom contains a program allowing a student to view any known place from any other known place through a telescope: one can look at Earth from the Moon for instance, and receive technical information about it. You can copy the CD-Rom onto another blank CD or put it on a hard drive for free. The book's included on-line supplemental course features are interactive and reiterate the book's material.
I have not opened the envelope containing the on-line password for fear of reducing the sell-back cost at my college--once a student has opened the envelope containing the on-line pass code key, the envelope cannot be sold back, can only be used once. I regret not having used it, because the Pearson, Addison-Wesley website was extremely helpful in one other course in which I used its on-line supplements. I can only imagine how beautiful the on-line astronomical images are. I would steal the images and put them on my computer desktop, or make a screen saver with them. Maybe I'll open it now, anyway, even though I'm nearly through the course.
If you purchase this text book here at Amazon, make sure you also receive the envelope, because it is worth around thirty or forty dollars. Students can buy the code at the web site without the envelope, but know that the envelope is part of the text book and should come with it unless the seller provides product information stating otherwise. I once had someone sell me a text for college algebra on Amazon with a price about thirty dollars less than Amazon's price. When I received the algebra text, it didn't have the envelope with it! The text was also used-but-wrapped-in-plastic, even though that product description stated the book was new! It may have come to me in plastic, but it wasn't new! Because the envelope containing the on-line code was missing, I peered closely at the book itself and confirmed that the book was USED, because of dirty palm prints on the book. I called the seller and sent it back at the seller's cost with the included mail-return sticker. I don't like people selling me something under false pretenses! Make sure the envelope is in the wrapper; otherwise, you're giving away thirty or forty bucks. Make sure also that the CD-Rom is in there, too.