Which material makes the best heat shield?
The question
Which wrapping keeps an ice cube from melting the longest?
A falling meteorite's surface melts and is swept away, but the inside stays cool because rock does not let heat through quickly and the fall is over in seconds. Spacecraft heat shields work in a similar way.
Equipment
- Ice cubes of the same size
- Wrapping materials: foil, cotton wool, bubble wrap, newspaper, fabric, nothing
- Small plastic cups
- A timer and a thermometer for the room
Method
- Wrap each ice cube in the same amount of one material and put it in a cup.
- Leave them all in the same warm place, away from direct sunlight.
- Check every 10 minutes and note which ice cubes have melted.
- What to measure
- The time each ice cube takes to melt completely, and the room temperature.
- How to present it
- A bar chart of melting times and a short explanation of insulators, linked to the fusion crust on a meteorite.
- Take it further
- Find out what fusion crust is, and why a meteorite is not hot when it lands.
Safety
Mop up meltwater so nobody slips. Do not use heaters, hairdryers or flames.