In the beginning of this year of science we explored astronomy. Our class covered the sun, the Big Bang theory, the inner and outer planets, stars, planetary orbits, and the moon. My favorite topic out of all of these is by far studying the inner and outer planets. First of all it was fascinating to learn about how far away all the planets are from each other. The distance is very difficult to even fathom. Another interesting aspect was that the first four planets in our planetary system are considered rocky planets, meaning that they are made of rock, save Earth which of course is made of rock and water. These first four planets, in order from the sun, are Mercury, Venus, Earth, and Mars. The last four planets in our planetary system are called gas giants, meaning that they are huge planets made mostly of gas. They are much bigger than the rocky planets. In order, the gas giants are Jupiter, Saturn, Uranus, and Neptune. Separating the two types of planets, in between Mars and Jupiter, is a large orbit of asteroids called the Asteroid Belt. I enjoyed learning about this because the size and distance difference in planets fascinates me.
Following astronomy was weather and climate, with some emphasis on the Earth's atmosphere. We studied the global warming theories, acid rain, how the sun heats Earth's surface, the ozone layer, weather patterns, and the layers of the atmosphere. My favorite topic out of these was learning more about global warming theories. I already had some previous knowledge on this subject, but I learned much more about it and got more in depth. Global warming is a theory that the sun is gradually heating our Earth more and more. This happens because the ozone layer, an atmospheric shield protecting the Earth from harmful UV rays, is depleting. Harmful gases like carbon dioxide emisions from our cars and factories combine with ozone molecules, destroying them. This allows more sunlight to seep through and heat up our Earth, which can be harmful in many ways. Certain animals that cannot withstand the growing heat in their environments could lose their habitats, like polar bears in the Arctic, which are melting rapidly over recent years.
After studying weather and climate, we moved our focus to geology. This involves the studying of rocks and the make-up of Earth. Our classes learned about the layers of Earth, plate tectonics, continental drift, sea-floor spreading, volcanoes, geologic time periods, and a lot of emphasis on rocks and minerals. My favorite topics in this segment go together. They are continental drift and geologic time periods. Continental drift is the theory that the continents weren't always in their present positions. The theory states that that the continents were at one point, millions and millions of years ago, joined together in one super continent called Pangaea. Over time, tectonic plates shifted the continents away from each other and into their present places. If the theory is correct, then that would mean that the continents are still gradually moving. Geologic time periods are Paleozoic, which is considered ancient life. It was in this time period that Pangaea existed and sustained life. In the Mesozoic era, considered middle life, Pangaea broke apart. In the Cenozoic era, considered modern life, the continents shifted into their present day positions.
Following the geology segment, we started learning about weathering and erosion. Weathering and erosion can occur many different ways on Earth, including water erosion, glaciers, and wind. I didn't have a single favorite topic in this segment because all the aspects we studied were so intriguing. At the end of this segment we used a program called Podcast to explain the types of weathering and erosion. My partner was my friend Blu, and we described all the types of weathering and erosion in our podcast, but what made this podcast memorable was the music we had in the background. To make our podcast more interesting for our classmates, we added Michael Jackson and The Commodores songs in the background. This made for one of the most enjoyable experiences in eighth grade science.
Our final scientific exploration in eighth grade Earth Science was learning about Earth's waters. We covered river systems, the water molecule, the stages of water, wetlands, groundwater, use of water, and ponds and lakes. My favorite topic of this segment was the use of water because of the amazing ratios of salt and fresh water. 70% of the Earth is water, and 97% of that water is salt water in the oceans and some seas. The remaining 3% of Earth's water is fresh water, but 3/4 of that is frozen in glaciers and ice caps, which is not able for use by humans. The last remaining percent of water on Earth, which is under 1%, is open for human use. Humans waste that water so much, and these statistics showed me how precious that fresh water is for us. This was an eye-opening learning experience for me.
All in all, I enjoyed using computer programs to learn about earth science in my eighth grade year. This is my final post, so I hope you enjoyed reading my blog. I'm now signing off from my eighth grade earth science blog.
