As mentioned in Part 1, not only is the "heliosphere" the boundary of the Solar System, but it is also the shield against harmful radiations. You may try the following activity at home and simulate the formation of this bubble:
- Print the image of the heliosphere on an A4-sized paper (image of the heliosphere can be downloaded here);
- Attach the paper onto a stiff surface such as cardboard or plastic board;
- Wrap the cardboard from Step 2 with plastic wrap or plastic folders and try to avoid wrinkles or air bubbles on the side with the printed image;
- Place the plastic wrapped image under the stream of water in the kitchen sink and move the image so that the water hits the location of the Sun;
- Tilt the image slightly to let water flow away from the "bow wave" side;
- Adjust the position of the image up and down and the amount of water coming out of the tap so that water clears out a bubble-shaped area that matches up the termination shock on the image.
The water flows quickly away from where it hits the image and clears out a bubble-shaped area. This is analogous to the solar wind from the Sun which blows away the interstellar medium and eventually subsides, resulting in a bubble we called "heliosphere".
Activity credit: NASA/IBEX
