The Study of the Universe

Scientists are explorers. Some travel to previously unknown regions, as did Charles Darwin to the Galapagos Islands, Robert Ballard to the floor of the Atlantic Ocean, and Jane Goodall into the rainforests of Africa. Other scientists stay home and use instruments as a means of discovery, such as using a microscope to reveal the world of tiny creatures in a drop of pond water.

To study the universe, scientists pursue both methods of exploration, and up until recently, staying home was the only option. Using telescopes and the power of their own thought and imagination, earthbound scientists observed and learned an amazing amount about our solar system and beyond. Evidence found in caves, tombs, and on pottery shows that people studied astronomy thousands of years ago, making astronomy one of the oldest sciences. Today’s technology has opened the boundaries. Humans have walked on the moon and space probes have toured some of the planets in our solar system – stuff that was once fantasy and science fiction!

Space Walk Space Station Phoenix on Mars Probe on Jupiter

The universe is everything that physically exists, including all matter, energy and space. The study of what is beyond the earth is called astronomy.

What Our Ancestors Saw For thousands of years, the sky has been a source of constant, predictable information. Long ago, people watched the sky to tell the time of day, the date, the weather, their position on the earth, and when the tides would be higher or lower than usual. Many first nations groups noted that the appearance of certain patterns of stars marked the changing of the seasons. This helped than determine when to plant and when to harvest crops.

Stonehenge, a monument made of huge stones placed in a circle, is a reminder of how important celestial observation was to ancient civilizations. It can still be used to calculate and predict celestial motions.

Celestial bodies is a term for any object that exist in space, such as the sun, the moon, and the stars. Farmers took their cues from the changes in celestial bodies, to plant and harvest crops. Sailors navigated by the stars. Political and religious leaders often made their decisions based on the information they received from those who studied the sky (astronomers).

During the time of the Roman Empire, the services of astrologers were especially in demand as people believed their destinies could be foretold by the stars. Navigation by stars was a valued skill for commerce and trade. –Prince Henry of Portugal, nicknamed the navigator, set up a school for sailor and was an important figure in Europe’s worldwide explorations.

Around the world, cultures and civilizations built observatories, created astronomical calendars, and developed the mathematics to predict planetary motion, eclipses, tides, and seasons.

Ancient China An Ancient Chinese Astronomical Observatory The water powered clock rotated the instruments in time with the daily motion of the stars.

Many different cultured had their own accounts about how celestial bodies were formed. In Hindu mythology, one story tells of seven wise men who married seven sisters. –Six of the women divorced their husbands and moved to another location. The six sisters all lived together in the northern sky. They became Pleiades. –The seven men became the seven stars of the big dipper. –The one wife who stayed with her husband became the star called Alcor, and remains by the side of Mizar in the crook of the Big Dipper’s handle.

An asterism is a distinct star pattern. A constellation is an officially recognized grouping of stars. Cassiopeia Perseus Orion Gemini The Dippers

When you look at a constellation, you may not see the shapes that people in ancient times saw. Today, rather than showing diagrams of animals or people, many books simply show the shapes to represent the constellations. Constellations have been used for thousands of years as calendars, timekeepers, and direction finders by people traveling in unknown territory – both on land and at sea.

A Star Map A star map of the night sky shows the relative positions of the stars in a particular part of the sky. A planisphere is a very useful type of star map that displays only those stars visible at a given date and time.

Historically, people formed these star patterns using their imagination to link up stars in the sky. Different cultures linked the stars in different ways. The Ancient Greeks thought that the stars that make up Orion depicted a great hunter. Some First Nations in North America thought the same stars looked like a canoe floating down a river.

Orion