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History - Prehistoric Astronomy

Prehistoric Ages. Since ancient times, man has gazed up at the stars at night. Since prehistoric times, man has observed the phases of the Moon during the lunar month, and the passage of the Sun during the solar year. Stone Age cave paintings still exist that show the phases of the Moon.

Some bodies moved faster in the night sky than the surrounding stars. These were the planets visible to the unaided eye: Mercury, Venus, Mars, Jupiter, and Saturn. The word "planet" comes from the Greek word "planetes," which means "nomad" (wanderer, traveler). To the Babylonians and Sumerians before them, the planets were "stray sheep." The image at left shows our planet, the Earth, and the Moon viewed from Nasa's Mars Global Surveyor.

The prehistoric ages date back to the Paleolithic (Early Stone) Age, which lasted from the first appearance of man to the end of the last Ice Age around 10,000 B.C.E. Neanderthal Man and Homo Erectus existed until about 30,000 B.C.E. The final period of the Paleolithic Age after this, during which only Homo Sapiens existed, is called the Upper Paleolithic or the Late Paleolithic Age.

The last Ice Age began about 125,000 years ago. The Last Glacial Maximum, when the Earth's ice cover was greatest, occurred about 15,000 BCE. Between 15,000 BCE and 5,000 BCE, most of the world's glaciers melted. This created new habitable land, while the sea reclaimed former beaches and even valleys. Massive earthquakes and volcanic activity during this time caused great upheavals around the world.

Myths of great floods occur in many of the world's cultures. Today, by examining sediment deposits and other clues, geologists have identified three times during the end of the Ice Age when massive ocean floods occurred in different parts of the world: approximately 13,000 BCE, 9,000 BCE, and 6,000 BCE.

Cave paintings still exist in a few parts of the world dating back to the last Ice Age in the Upper Paleolithic Age, notably the cave paintings at Lascaux and surrounding areas.

There was a transition from the Paleolithic Age to the Mesolithic (Middle Stone) Age around 11,000-9,000 B.C.E. During this time, man began to domesticate animals and live a more settled life.

The Mesolithic Age transitioned to the Neolithic (New Stone) Age, which spanned approximately 8,000-5,500 B.C.E. During the Neolithic Age, man began to grow crops of plants. This meant an end to a nomadic, hunter-gatherer lifestyle. To live near crops, man had to build homes. These homes were often built together in vilages. There are traces of an ancient Mother Goddess of Anatolia, "Cybele," from Cayanu (now Eastern Turkey) dating to ca. 7,000 B.C.E.

From Paleolithic to Neolithic times, man used stone tools. In following ages, man learned to work metal to make tools and weapons useful in agriculture, hunting, and war. The easiest metal to work was pliable copper. In the Calolithic (Copper Stone) Age, 5500-3000 B.C.E. man began to make tools from copper. The use of copper also encouraged trade for copper (and later other metals). This sent traders traveling far and wide. Expanding trade brought distant cultures in contact with each other throughout Europe, Asia Minor, and Africa. This trade also might have brought rise to early writing. Some of the earliest clay writings in Mesopotamia contain Sumerian loan records.

Traders also found that another metal, tin, could be melted with copper to form bronze. This discovery ushered in the Bronze Age, lasting from about 3000-1200 B.C.E. Copper and tin are both soft metals, but the bronze alloy they form is much harder. Bronze therefore made far better tools and weapons than either tin or copper alone. Traders also came to sell valuable gold and silver during the Bronze Age. Cities in Europe and Asia Minor contained increasing wealth during this Age, and a growing number of fortified towns developed, with walls protecting them from attack.

The Iron Age followed the Bronze Age, as man learned to work iron. By the time of the Iron Age, the extensive spread of trade had brought about the need for record keeping, which brought about formal writing. These written records preserved ancient histories for the ages, bringing an end to prehistoric times.

Our ancient ancestors pondered the motions of the heavens. They wondered what the stars and planets could be. Some ancient societies discovered the cycles of motion of the Sun, Moon, planets, and stars. They made these observations for many generations. Some made astronomical observations so accurately that they were able to predict eclipses of the Sun and Moon. A total eclipse of the Sun is shown in a NASA photograph at the left, taken by the Apollo 12 crew during their return flight to Earth. To most ancients, eclipses were bad omens.

Ancient astronomers recorded positions of the planets relative to the stars. They saw that the planets moved relative to the stars. The brightest stars were the easiest to spot. Stars of the first magnitude have been used for comparison since at least the days of ancient Babylon and probably long before then. Those stars are Aldebaran, Antares, Pollux, Regulus, and Spica. The Babylonians and others recorded two of these stars, Aldebaran (in Taurus) and Antares (in Scorpius), as exactly opposite each other and in the middle of their respective signs. They also recorded Spica (in Virgo) at or 1° distant from the middle of the Zodiac. Later, the Greek Astronomer Ptolemy (see below) combined his observations with those of his predecessor, Hipparchus, and defined the beginning of the Zodiac that became the standard among Western astronomers for almost 2000 years. They both drew upon observations recorded in Babylon, Egypt, and surrounding areas of the world.