Fifth Grade Earth Science
The name earth science implies that it is a science that focuses on the study of the earth. This is why many are surprised that astronomy and the weather or climate is included under this category. These two topics are considered a part of earth science because they are related to the earth. Studying the weather and climate, which directly affects the earth's plants and animals is something that is vital to the earth's survival. The stars and space, on the other hand are related to earth science because from their interactions, we can learn about what can or may happen to earth.
Star Map
A star map is a map of the night sky. Usually it shows the constellations (certain areas of space which show boundaries), connecting the stars with lines. These constellations were first connected by the creators of the first star maps. The constellations are what they saw in the night sky. There were ways that these first astronomers used to keep track of the night sky, hence becoming familiar with star positions and how they move. This meant they could later use these stars for navigation at night.
The first star map is credited to Chinese astronomers. Their constellations are different from the ones put together by Western or Greek astronomers who came next. Usually, constellations have stories behind them of how they came to be. These stories often involved the gods, who were believed to reside in the sky. Both Chinese and Greek star maps were used for navigation purposes. Studying the movement of the stars allowed astronomers to determine their position and the changing seasons.
When Copernicus proposed a heliocentric model for the solar system, one of the consequences of the earth moving instead of objects moving around the earth is that it implied that stars could be stationary. This means that the observed movement of the stars was really just a consequence of the movement of the earth. Though this was revolutionary, it did not change the ways in which star maps were used. They were still used for navigation, except now, explorers and sailors understood why after a while, familiar constellations seem to appear in different places or not appear.
We now understand that star maps have to be specific to certain hemispheres or regions of the earth. The constellations you see in the northern region can be different from those seen by equatorial regions of the earth. Though, because the earth is a sphere, some constellations do overlap. Different areas of the earth can observe different phenomena as well as different constellations. For example, the northern lights or Aurora Borealis is not seen in many parts of the earth. This light show in the sky can only be seen from the polar regions of earth.
Next Article: Creating a Star Map
