Cumberland Times-News

July 27, 2013

Here’s a fine book for learning about planets

Bob Doyle, Columnist
Cumberland Times-News

— A few weeks ago, I picked up a new space book from the book bin of a large discount store.

“Discover More (about the) Planets” was a real find. The book was published last year by Scholastic, Inc., specializing in media for school age students; its ISBN is 978-0-545-33028-2. The authors are Penelope Arlon and Tory Gordon-Harris.

The first thing I noticed was an introduction on how to use this book; in each section, there are icons of what is visible to the eye, where to find more information on subsequent pages of the book, and data in boxes that are particularly interesting.

The table of contents has many entries, allowing a reader to quickly find a topic of most interest. The glossary towards the end of the book is not too detailed but essential for beginners. The book ends with an easy to use index.

“Discover More Planets” is only 80 pages in length, a good length for an introduction to our solar system. This book’s cost is $12.99.

The first section starts with a definition of a planet as being a round object that moves about a star, reflecting light from that star.

Planets are divided four ways: rocky planets, gas giants, dwarf planets and planets beyond our sun (often called extra solar planets). But we can’t forget about moons that orbit planets; some moons are bigger than the smallest planet Mercury.

The next section explains our place in the universe with beautiful graphics, going from home to our galaxy. The solar system is next defined as the kingdom of our sun, showing the relative sizes of all the regular planets.

Of these eight planets, six are named after Roman gods or goddesses. The two exceptions are: Earth from the Anglo-Saxon word “Erda” for soil and Uranus named for the Greek god of the heavens.

A brief history of Space exploration notes that the German V-2 rocket was the first man made object to rise above our atmosphere and that Dennis Titov was the first space tourist in 2001. (His ticket price was $20 million!).

The sun gets special notice, being the largest member of the solar system; but among the stars, our sun is only a middle sized star. Mercury gets baked by the sun during the day (800 F) but deep frozen during its long night (-300 F). Venus has the hottest surface (900 F), owing to its compressed atmosphere of carbon dioxide.

The Earth has been called “the Goldilocks” planet, for its just right temperature, atmosphere and surface gravity. These great conditions allow life to have developed in its many forms.

Our constant companion is the moon, that shows only one side to Earth. The changing shapes of the moon (dark moon, crescent, half full, gibbous and full) are explained. There is a nice map of the full moon, showing the main craters and lunar lava fields.

We can’t forget that the moon is the only world that humans have reached. In addition, we have put many thousands of artificial satellites (Mini-Moons) in Earth orbit. About 3,000 satellites are working and 20,000 others, sad to say are useless pieces of space junk. Our best known unmanned satellite is the Hubble Space Telescope, still working after being in orbit since 1990.

Mars is given a nice treatment; its rusty color is from iron oxides in its soil. Mars is half as wide as the Earth but has some features (such as volcanoes, canyon valleys) that dwarf those on Earth. Most asteroids or minor planets stay in the asteroid belt between Mars and Jupiter but some asteroids can be thrown out of their usual orbits and head towards the Earth.

Our last asteroid encounter was on Feb. 15 of this year when a house-sized asteroid exploded high over a Russian city; its shock waves shattered thousands of windows.

Other sections cover the giant planets, the objects beyond Neptune (includes the dwarf planet Pluto), the different types of stars, galaxies, planets about other stars, the Big Dipper, the biggest space rockets (now Europe’s Ariane 5), the International Space Station and our future in Space.

This book is recommended for school libraries and the children’s sections of regular libraries.

SKY SIGHTS AHEAD: The planet Mercury is nearly at its greatest angle to the west of the sun at dawn. If you rise about 5:30 p.m., you have a chance to see the bright planet Jupiter, the planet Mars (below Jupiter) and Mercury (lowest of the three planets) low in the east.

In the evening sky, there are two planets seen in the early evening. Brilliant Venus is low in the west in the twilight (try 9:15 p.m.). As it gets darker, look to the left of Venus to see Spica (brightest star of Virgo) and yet farther to the left to spot Saturn, shining steadily.

Bob Doyle invites any readers comments and questions. E-mail him at rdoyle@frostburg.edu . He is available as a speaker on his column topics.