9th Grade Earth Science

There are many cycles throughout the universe.

1. Stars condense by gravity out of clouds of molecules of the least massive elements until nuclear fusion of the lower mass elements into heavier ones begins to occur. Fusion releases great amounts of energy over millions of years. Eventually, some stars explode, producing clouds of heavy elements from which other stars and planets could later condense. (AKSci - A.3)

o Predict the relative stage in respect to a star's life cycle, given the characteristics of the star.

o Conduct research, organize information, and present findings that describe the cycles of stars.

There is order in the universe.

1. The stars differ from each other in size, temperature, and age, but they appear to be made up of the same elements that are found on the earth and to behave according to the same physical principles. Most stars are in systems of two or more stars orbiting around one another. (AKSci - A.3)

o Describe the sun's stage within the star cycle.

o Infer the steps in the evolution of our sun.

o Compare the Milky Way with other galaxies.

2. The sun is a medium-sized star located near the edge of a disk-shaped galaxy of stars, part of which can be seen as a glowing band of light that spans the sky on a very clear night. The universe contains many billions of galaxies, and each galaxy contains many billions of stars, to the naked eye, even the closest of these galaxies is no more than a dim, fuzzy spot. (AKSci - A.3)

o Describe the sun's stage within the star cycle.

o Infer the steps in the evolution of our sun.

o Compare the Milky Way with other galaxies.

3. Differences in densities and temperatures results in layers in both ocean and atmosphere. (AKSci - A.1, A.4)

o Demonstrate similarities and differences between atmosphere and oceans in relation to their temperature and density.

o Describe the behavior of density currents after combining salt solutions of varying concentrations.

Natural systems undergo change.

1. Climates have sometimes changed abruptly in the past as a result of changes in the earth's crust, such as volcanic eruptions or impacts of huge rocks from space. Even relatively small changes in atmospheric or ocean content can have widespread effects on climate if the change lasts long enough. (AKSci - A.4)

o Illustrate and describe the movement of air or water in a convection cell with respect to an energy source.

o Conduct research, organize information, and summarize findings regarding forces causing crustal plate movement, space impacts, and their impact on determining the geologic age and climate of the earth.

o Use recent understandings of meteor and comet impacts as a geologic process to suggest possible revisions to extinction theories.

o Research an extinct organism to discover the environmental pressures that may have contributed to its demise.

o State the advantage of using plate tectonics theory to predict possible locations of earthquakes and volcanoes with that of using only historic (including folk) records.

Many of the earth's features are the result of processes which occur over long periods of time.

1. Plants alter the earth's atmosphere by removing carbon dioxide from it, using the carbon to make sugars and releasing oxygen. This process is responsible for the oxygen content of the air. (AKSci - A.9, A.14c)

o Design and use a variety of models to show how plants cycle elements through the atmosphere, hydrosphere and biosphere.

o Describe the influence of photosynthesis on the earth's atmosphere over time.

o Relate their findings to the production and consumption of materials by the organisms after using a respirometer to measure the respiration in plant or animals.

2. The solid crust of the earth--including both the continents and the ocean basins--consists of separate plates that ride on a denser, hot, and gradually deformable layer of the earth. The crust sections move very slowly, pressing against one another in some places, pulling apart in other places. Ocean-floor plates may slide under continental plates, sinking deep into the earth. The surface layers of these plates may fold, forming mountain ranges. This movement can cause earthquakes and volcanoes. (AKSci - A.7)

o Design a laboratory investigation model to identify the forces and motion in convection currents and describe and illustrate the relationships between the model and the crustal plate movement of the earth.

o Judge the validity of the hypothesis that the Pacific Plate is subducting beneath North American Plate using plots of earthquakes in Alaska.

3. The slow movement of material within the earth results from heat flowing out from the deep interior and the action of gravitational forces on regions of different density. (AKSci - A.7)

o Design a laboratory investigation model to identify the forces and motion in convection currents and describe and illustrate the relationships between the model and the crustal plate movement of the earth.

o Judge the validity of the hypothesis that the Pacific Plate is subducting beneath North American Plate using plots of earthquakes in Alaska.

4. The theory of continental drift, first proposed in the 1600's and reintroduced in the early 1900's by Alfred Wegener, was not fully accepted until the 1960's when further evidence had accumulated in support of it. (AKSci - C.7, C.8)

o Design a laboratory investigation model to identify the forces and motion in convection currents and describe and illustrate the relationships between the model and the crustal plate movement of the earth.

o Judge the validity of the hypothesis that the Pacific Plate is subducting beneath North American Plate using plots of earthquakes in Alaska.

5. The densities of both water and air are altered by inputs of energy (commonly from sun). These density changes result in the wind and water currents which affect the weather and heat distribution throughout the planet. (AKSci - A.9)

o Illustrate and describe the movement of air or water in a convection cell with respect to an energy source.