For Spigot Science Magazine -- 2008 May/June

Theme: Earth in the Universe


†† How We Learn About the Universe

By Glenn A. Walsh,

Past Astronomical Observatory Coordinator,

The Buhl Planetarium and Institute of Popular Science, Pittsburgh

Electronic Mail: < >



Thousands of years ago, men and women looked up at the sky and pondered the meaning of what they saw. They quickly learned that some sky objects, such as the Sun and the rain, were vital to their lives. They wondered if the tiny lights in the nighttime sky also had meaning in their lives.


This led to complex mythologies derived from the organization of stars into constellations or star pictures. And, as more patterns were identified, astrology began as a forerunner of Astronomy, often as part of religious rituals.


Early astronomical observatories, such as the famous Stonehenge in England, document the sophistication of these early sky watchers. This led to early calendars and eventually to clocks and watches.


The invention of the telescope, which celebrates its 400th anniversary next year, first used for astronomical observing by Galileo, completely transformed Astronomy, as it allowed much more detailed observations of objects that had previously been a mystery to mankind. Soon, telescopes became larger, and hence able to view more distant objects with greater detail, and mankindís knowledge of the Universe greatly increased.


Nineteenth century astronomer Samuel Pierpont Langley developed a New Astronomy, later known as Astrophysics, which concentrates on measuring the celestial bodies and analyzing their physical composition, structure, and other properties. New instruments, such as the spectroscope which analyzes the light from stars to determine their composition, were invented.


Another revolution in astronomical research came 50 years ago with the launch of unmanned space probes by Russia and the United States. It has been said that each time one of the space probes, such as Voyager I or II, passed one of the outer planets (Jupiter, Saturn, Uranus, Neptune), mankind learned more about each planet in just 24 hours, than had been learned in all of previous history!


Mankind has not settled for just sending robots into space. Since 1961, men and women have started traveling into space for even more detailed exploration. On July 20, 1969, astronauts Neil Armstrong and Buzz Aldrin were the first of twelve Americans to explore the Moonís surface. Current plans are for more astronauts to return to the Moon within the next twenty years, and to Mars later on..


Scientific exploration is not the only reason for people to extensively explore outer space. As the world population continues increasing, and resources to support that population continue dwindling, we need to find new resources, out there, to help support the people on our planet.


You can learn more about Astronomy and Space Sciences in several ways. Of course, the Internet is a wonderful new resource, however you have to be cautious of the source of various web sites. To ensure you are receiving reliable information, you should always use web sites of major scientific organizations, such as NASA, and universities. Public libraries are also a wonderful resource for finding reliable scientific information.


If available in or near your community, you can also visit a planetarium, science center or museum, or an astronomical observatory (often located at a local college or university) to learn more about Astronomy. And, you can inquire at your public library or planetarium whether an amateur astronomers stargazing club exists in your area.