There is a lot of information known about planet earth; however, every day new and astonishing little known facts are discovered. These facts are the result of research by scientists who spend their time investigating phenomena, acquiring new knowledge, or correcting and integrating prior knowledge into theories and facts that explain how the earth works. The study of earth and its related sciences is called earth science.
Investigations in earth science have produced a wealth of new knowledge and little known facts that are derived from the five major disciplines. These disciplines are geography, geology, planetary, geophysics, and geodesy. These major disciplines use physics, chemistry, biology, chronology, and mathematics to build a quantitative understanding of the earth system.
Teaching and Learning
One lead group that studies earth in great detail is the National Aeronautic and Space Administration (NASA). The lead investigators for NASA are the Jet Propulsion Laboratory and the California Institute of Technology. Their earth science communication team compiles information of well known and little known facts about planet earth.
The advantage of these facts in earth science is that they provide enrichment information to support teaching and learning, especially when students ask questions as they make critical connections in earth science.
Earth is not Perfectly Round – this little known fact is based on the fact that the diameter of the earth is 7,900 miles from the North Pole through to the South Pole. The diameter of the earth through the equator is 7,926 miles. This slight equatorial bulge is due to the rotation of the earth. This bulge is expected to grow larger as the ice caps at the North and South Pole continue to melt, along with glaciers around the world. This melting is due to an accelerated change in climate, because of global warming.
Earth Days are Getting Longer – today an earth day is 24 hours long; however, the length of a day is increasing by 1.7 milliseconds every century. Approximately 60 million years ago an earth day was only 21.6 hours in length. This every increasing length in an earth day is due to the gravitational pull of the moon, which is causing earth’s rotation to slow down.
Ice Ages – approximately 800 million years ago the earth went through several periods of ice ages leaving the earth looking a like a giant snow ball in space during each ice age. The earth was frozen from North to South Pole and planet’s average temperature was minus 74 degrees Fahrenheit. Earth science investigations have discovered that only microscopic and simple cell organisms lived on earth during this period.
Driest Place on Earth – this place has only had one recorded rainfall in the last 400 years. It is also located next to the largest body of water on earth. This place is the Atacama Desert in Northern Chile. One edge of the desert lies along the Pacific Ocean. The desert is so dry that green photosynthetic micro-organisms which live in rocks and under stones cannot be found.
Gravity is not Uniform – because the earth is not a perfectly smooth sphere, the pull of gravity is not even. Mountain ranges, such as the Rockies and Himalayas, cause positive anomalies, which result in an increased pull of gravity. Deep trenches in the oceans, such as the Marianas Trench, and dips in the earth’s crust caused by large glaciers during ice ages cause negative anomalies. These negative anomalies cause a decreased pull of gravity. Other factors include the movement of tectonic plates and movement of the oceans.
Moons or Moon – there are two other objects, other than the moon seen from planet earth, orbiting the sun near earth. One of these objects circles the sun once each year like earth. This object follows earth around the sun relatively close. This object is called 3765 Cruithne and was discovered in 1986. The second object is called Asteroid 2002, which comes as close as 3.7 million miles every 95 years. Some scientists have suggested that these objects should be considered as additional earth moons.
Making Connections With Little-Known Earth Facts
Earth science, just like all other sciences, is constantly discovering new facts which update or add to prior knowledge. For example, Pluto was named a planet in 1930 and recently reclassified as a non-planet in 2006; causing an upheaval in the science and education communities. However, often new facts do not become common knowledge and are relegated to the status of little known facts.
Often facts that are not common knowledge are the most interesting and grab students’ attention, along with a peak in interest to learn more about these little known facts. This is the basis of teaching and learning in science, the desire to learn and share more information about the known or unknown.
David R. Wetzel - Dr. David Wetzel's experience includes more than 25 years in continuing, adult, and teacher education.
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