While we can clearly see impact craters on the moon, on Earth they are largely hidden.
Earth is subjected to a number of localized forces, including those that are geological, meteorological and volcanic in nature. However, our planet is also affected by external forces, which—at times—can disturb and otherwise interact with terrestrial conditions. The relationship between Earth and the space surrounding it is a complex one. Some space and Earth-science student activities include simulating impact craters, making a magnetometer and imitating the slingshot effect.
Simulating Impact Craters
Impact craters are deep, gigantic holes—sometimes miles in diameter—that are caused by meteorites and comets crashing into a planet’s crust. While we can clearly see impact craters on the moon, on Earth they are largely hidden, due to weathering, shifting tectonic plates and other destructive terrestrial processes. According to usc.edu, you can recreate the formation of impact craters by dropping projectiles (such as rocks) into containers filled with sand. Carefully measure the diameter and weight of each projectile you drop, as well as the precise height from which you drop it. Also, make sure you level off the sand after each drop, and add a bit more if necessary to keep the depth consistent. How did the heights, weights and diameters of your makeshift meteorites affect the depth and diameter of the resulting craters? (Note: you may want to videotape or photograph each drop and crater for comparison).
Make Your Own Magnetometer
A magnetometer is an instrument used for measuring changes in Earth’s magnetic field or magnetosphere, which is an invisible field made up of electric charges surrounding the planet. The magnetosphere absorbs and protects us from the sun’s harmful radiation; however, sometimes this radiation—in the form of solar flares—can be so strong that it causes the magnetosphere to move. According to usc.edu, you can measure this movement using a magnetometer made primarily from household materials. To construct, first attach a magnet to one side of an index card and a small mirror to the other. Suspend the card from a string inside an empty 2-liter soda bottle and seal. Shine a laser pointer onto the mirror so that its beam reflects on to an adjacent wall, and mount the laser so it remains fixed in that position. Tape up a ruler horizontally to the wall so that the beam hits, and track the movement of the beam over the course of several hours. During periods of high solar flare activity, you should notice corresponding changes. (See Resource 1 for a live solar flare feed.)
Imitate the Slingshot Effect
NASA uses the slingshot effect in order to shoot spacecraft out into deep space, while minimizing fuel consumption. They do this by positioning the spacecrafts into Earth’s orbit, and using the natural gravitational forces to carry them around and around until finally they are released. According to cool-science-projects.com, you can imitate the slingshot effect by securing a rock or stone to the end of a rope or string and then swinging it around in a circle. If you let the string go in midswing you will notice that your rock will not continue in its orbit, but will be shot outward.