The Everything Astronomy Book

Discover the mysteries of the universe

Cynthia Phillips, Shana Priwer

• Publisher: Everything
• Year: 2011
• Print ISBN: 9781580627238
• eBook ISBN: 9781605505749
• Topic: Scienze fisiche
• Subtopic: Astronomia e astrofisica

The Everything Astronomy Book, by noted SETI Institute scientist Dr. Cynthia Phillips, helps you stargaze with authority. The book not only provides clear descriptions of all the theories of the origins of the universe, it explains the facts about the planets, moons, and stars in language anyone can understand-completely free of the usual astro-jargon. In addition, common myths are debunked: Find out why the Big Dipper is not an actual constellation, and that a shooting star isn’t really a star at all!

CHAPTER 1

Ancient Eyes, Same Sky

Our ancestors used the sky in religion, science, philosophy, and countless other aspects of their lives. Ancient Egyptians observed the heavens for religious and civic purposes; Native Americans used medicine wheels to study and interpret the skies; Chinese astronomers were some of the first to study sunspots. Astrology itself emerged as a way to use astronomy to predict certain events and life patterns.

FIGURE 1-1:
Timeline of ancient astronomy 50,000 B.C. to 5000 B.C.

(refer to page 278 for more information)

Archeoastronomy

Archeoastronomy is, as you might expect, a blend of archeology and astronomy. It combines the study of religion, folklore, celestial myths, and all ancient astronomical rituals and ideas. Often demonstrated through ancient writings and artifacts, archeoastronomy gives us a comprehensive, multicultural view of how modern astronomy came to be.

The origins of astronomical observation and representation date back at least as far as 20,000 B.C. While most Paleolithic art focuses on the representation of earthly creatures such as animals, Neolithic rock art with astronomical themes has been uncovered in Spain, Portugal, and France. These paintings and petroglyphs (rock carvings or drawings) depict the Sun, various planets, and several identifiable constellations. Sun images are often present in depictions of religious scenes, and much more about Sun gods is seen in later drawings and writings.

Prehistoric Astronomy

Stonehenge, located in England, is one of the more physical examples of an ancient culture celebrating the heavens. It consists of thirty stones, each approximately 30 feet in diameter. The entire structure was built in either four or five stages, probably between 3100 and 2300 B.C.

FIGURE 1-2:
Timeline of ancient astronomy 3000 B.C. to 2000 A.D.

(refer to page 278 for more information)

FIGURE 1-3:
Stonehenge

(refer to page 278 for more information)

Stonehenge is oriented to align with the sunrise of the summer solstice; on that day, the Sun supposedly shone directly onto the Altar Stone. Stonehenge is generally considered to be a three-dimensional calendar. It is thought that Stonehenge was constructed to predict the optimum times for agricultural and religious events.

Astronomical observation was also an important part of Stone Age life in countries such as Ireland. Neolithic star stones dating back 4,000 to 5,000 years have been discovered, indicating an early awareness of celestial movements. The Solstice Stone found near Beltray marks both the summer and winter solstice; similarly, the Double Alignment stones at Barnaveddoge are aligned to both sunrise and sunset at the two solstices.

Stonehenge is located in Salisburg Plain, Wiltshire in southern England. Plan your visit carefully; on June 21 every year, from the Altar Stone, the Sun can be seen rising directly over the top of the Great Stone.

Astronomical monuments dating from early prehistoric times to the Bronze Age are also found in Scotland. Solstices were family and village events, and there is evidence to suggest that everyone in the village helped with the building process, from the quarrying of stones to the erecting of the rock circles. Located mainly in the northeast and southwest of Scotland, the circles are thought to mark a particular horizon point for different celestial events. Chambered cairns are also located all over Scotland. Cairns consist of stones that mark hidden chambers, and are thought to have served as vantage points for observing social or spiritual rituals.

Other countries and regions also have long astronomical histories. Australian Aborigines, some of the earliest astronomers, incorporated the heavens into their religious and civil lives at least 40,000 years ago. Aborigines are sometimes called the oldest astronomers in the history of time; the very word aborigine means “people who have been here since the beginning.” Tool artifacts have been discovered from 20,000 years ago; artwork provides evidence to suggest that Aborigines used stars for the planning of rituals, hunting, food gathering, and navigation. Aborigines made accurate observations of celestial events, largely without the use of viewing instruments.

Was there a real star of Bethlehem that the Magi followed, one that heralded the birth of Jesus?

Astronomers have suggested that the “star” could have been a supernova, a new comet, or the conjunction of two bright planets sometime between the years 8 B.C. and 4 B.C., which is when most historians think Jesus Christ was actually born.

The writings of Julius Caesar tell us that the Teutonic people, residents of Germany and Denmark, worshipped the Sun and Moon as far back as 1200 B.C. Rock carvings found in Denmark, dating to 1000 B.C., illustrate the Sun and fire as deities. A stone ring in the Danish city of Andebjerg clearly shows markings to observe sunrise at the summer and winter solstices and equinoxes.

What we can abstract from this study of prehistoric and early civilizations is that just about everyone, on every continent, figured out a way to observe the heavens and record their findings. Some countries attached extreme religious significance to the heavens, while others used the stars as a means to ensure subsistence. In all respects, we see the importance of astronomy in the religious, civil, and political lives of early peoples.

Egyptian Astronomy

Ancient Egyptians were extremely advanced in mathematics, astronomy, and physics. From 7000 to 6000 B.C., evidence of megalithic stones and stone rings suggests the beginning of early observations. A circle of standing stones located near Nabta bears a striking resemblance to Stonehenge, while predating it by over 1,000 years. The circle was likely used for the sighting and viewing of the solstices.

The Pyramid Texts, dating back to 3000 B.C., are the oldest surviving documents from the Egyptian heyday. Venus and Mars are referred to extensively, and the Pharaoh is constantly linked to the stars and planets. Star gods and goddesses played a critical role in the politics and religion of early Egyptian society. The star Sirius guided the creation of their calendar year, helping them predict when the Nile would flood and make the land fertile.

The three pyramids of Giza, arranged on a site called the Memphite Necropolis, were built between 2533 and 2505 B.C. In the Egyptian belief system, all Pharaohs were considered to be direct descendants of the Sun god Ra, so the connection to astronomy was a clear part of their everyday lives. Egyptians also believed that Egypt paralleled the cosmos, and was a direct representation of a land in the skies.

FIGURE 1-4:
Pyramid paralleling alignment.

(refer to page 278 for more information)

The arrangement of these three pyramids has been interpreted to represent the three stars of the constellation Orion’s belt. While the positions of the stars have changed over the last 4,500 years, it is possible to make adjustments for these changes and analyze the pyramids’ positions based on what the Egyptians would have seen. Aerial views of the Memphite site reveal that the pyramids seem to correlate fairly well to the orientations of the Belt Stars.

Native American Astronomy

Astronomy was one of the basic components of Native American life. Seasons, spiritual ceremonies, time, and the calendar were defined by the stars. Three different aspects of the diverse Native North American cultures help us to understand the incorporation of celestial bodies into their lives: Chaco Canyon, medicine wheels, and information we have about the Lakota tribes. South American Native civilizations also used the stars to create detailed calendars, and for other purposes.

North American Cultures

Many different Indian tribes inhabited New Mexico’s Chaco Canyon, including Aztecs in prehistoric times, then Anasazi and Navajo hundreds of years later. The canyon served as the homeland for a large farming society that used the stars to anticipate the changing of seasons, and therefore their livelihood. Buildings were planned to correlate directly with the alignment of the heavenly bodies, especially Sun, Moon, and Earth. Chaco residents constructed kivas, partially underground chambers used for spiritual rituals, which were aligned exactly with the summer or winter solstice.

Kivas may have been used for astronomical observation. Native Americans recorded supernovas and other astronomical events, possibly from these kivas. The supernova of A.D. 1054, which formed the Crab Nebula, was the best known of these events, and a petroglyph high on the canyon wall may depict this celestial event. Other artifacts also indicate their interest in the heavens, including the Sun Dagger, a rock formation found in Chaco Canyon, which may have functioned as an early calendar.

Medicine wheels, rock arrangements closely resembling spoked wheels, are found all over Native American territory. One of the earliest known medicine wheels was found at Moose Mountain in Saskatchewan, and dates to approximately 600 B.C. Many early medicine wheels were also created by the Plains Indians in regions all over the United States and Canada. The Big Horn Medicine Wheel in Wyoming, used between A.D. 1500 and 1700, is one of the best preserved of these wheels.

Kivas were underground chambers constructed by several different Native American tribes. Spiritual rituals and astronomical observations—supernovas, comets, and even nebulae—might have been observed from kivas.

The Lakota Sioux Indians were particularly attuned to the movements of celestial bodies. They used the stars to guide them on hunting expeditions and to plan religious ceremonies. They used the direction and length of the Sun’s shadow to determine when equinox was approaching, and based their calendar on these events. The Black Hills, a Lakota territory in South Dakota, contained several ceremonial locations. Each depicted a different constellation, as Lakota Indians considered the sky and earth to be mirror images of each other.

South American Cultures

The Mayans, a group of Native American civilizations living in different regions of Mexico, Guatemala, Honduras, and Belize, also used astronomy. Early Mayan culture began when civilization took root in Central America, around 10,000 B.C. The Pre-Classic Mayan period (1500 B.C.–A.D. 300) represented the cultivation of language, in addition to building and record keeping. The Mayans had a Sun...

Table of contents

• Cover
• Title Page
• Dedication
• Contents
• Introduction
• Chapter 1: Ancient Eyes, Same Sky
• Chapter 2: Astronomy As a Science
• Chapter 3: How the Universe Came into Being
• Chapter 4: Constellations Patterns in the Sky
• Chapter 5: Navigate the Night Sky
• Chapter 6: The Inner Solar System
• Chapter 7: The Outer Solar System
• Chapter 8: Solar System Wanderers
• Chapter 9: A Star Is Born
• Chapter 10: Deep-Sky Objects
• Chapter 11: Faraway and Far-Out
• Chapter 12: First Steps, First Tools
• Chapter 13: Telescopes Advanced for Advanced Viewing
• Chapter 14: Visit Space Places
• Chapter 15: Make Your Own Scientific Discoveries!
• Chapter 16: Ground-Based and Space-Based Observation
• Chapter 17: Robots, Animals, and People in Space
• Chapter 18: SETI Are We Alone?
• Chapter 19: How It Will All End
• Appendices
• Color Photograph Reference
• Copyright