In this activity students will use a circular coordinate grid to plot zones of auroral activity.
For teacher:
For each student:
Auroras are the beautiful curtains of colored light that are commonly seen in the Arctic and Antarctic regions of Earth. They have a long history of sightings by humans for over 3,000 years. Like lightening and earthquakes, the auroras are natural events.
Auroral light is created by interactions between the sun and Earth. The sun is a mass of electrically charged particles (in the form of a gas). The sun is so hot that it's outer layers blow away in the form of solar wind. It takes an average of three days for this wind to reach Earth. In general, Earth's protective atmosphere and magnetic field protect the planet from this solar wind. Instead of penetrating our atmosphere, particles from the sun collect around Earth and gather in a cavity called the magnetosphere.
Energized electrons from the sun collide with oxygen and nitrogen in Earth's atmosphere, producing colorful arrays in Earth's magnetosphere. The different colors of the auroras are created depending on the molecules and altitude of collision. A yellow-green color is the result of an oxygen collision at 100 km. Red auroras occurs at 300 km. Blue light results from ionized nitrogen molecules, and a purplish-red color is the result of neutralized nitrogen molecules.
It is easy to graph the auroral zone using angles and a geographic circular grid of the Northern Hemisphere. This activity is a great follow-up to "Tomb Robbers." Prior to this activity, students should be familiar with benchmark angles and the circular grid system. They should be able to plot points on a circular grid and estimate and draw angles with minimal error.
In this activity, students use a circular coordinate grid to plot zones of auroral activity.
This grid system is different than a coordinate grid because it is circular. Astronomers often use circular grids to identify objects in the night sky. To locate points on a circular grid, start at the vertex and then move out to the latitude given by the first coordinate of an ordered pair, then move counterclockwise along that circle the number of degrees indicated by the second coordinate.
Vocabulary terms used in this lesson:
angle - The opening between two straight lines that meet at a vertex, measured in degrees.
coordinate grid - A two-dimensional system in which the coordinates of a point are its distances from two intersecting, straight lines called axes.
coordinates - An ordered pair of numbers that identify a point on a coordinate plane or grid.
latitude - A geographic coordinate measured from the equator with positive values going north and negative values going south.
longitude - A geographic coordinate measured from the Prime Meridian (0˚ longitude) with positive values going east and negative values going west.
2. Become mathematical problem solvers.
Invitation to Learn
Display several photos of the Northern Lights for the students.
Use some of the following questions to guide a brief class
discussion:
Instructional Procedures
Have students complete the Southern Lights worksheet.
Research Basis
Joram et. al., (2005). Children's Use of the Reference Point Strategy for Measurement Estimation. Journal for Research in Mathematics Education, 36(1), 4-23.
"Mathematics educators frequently recommend that students use strategies for measurement estimation, such as the reference point or benchmark strategy… Relative to students who did not use a reference point, students who used a reference point had more accurate representations of standard units and estimates of length."