A couple of weeks ago in my high school astronomy class I asked students to share common science misconceptions that we've discussed in class in preparation for an activity in which those students would attempt to correct the misconception in such a way that an 8 year old would walk away with a clear understanding. This is more difficult than may seem as an 8 year old does not have the educational background an adult has. It also stresses the important of discussing complicated science in a way that the general public can understand.
The misconception we chose was the cause of the seasons. Too often kids are taught we have seasons on Earth due to Earth's changing distance from the Sun. Not true. We have seasons due to Earth's tilt, as I previously discussed here. Students had to discuss and formulate a way to explain this to an 8 year old. After a few minutes I selected a handful of students to give it a shot at the front of the room.
Granted, I did not give my students long to think about this and it is much more difficult than it looks, but one student used hot water from a faucet onto a metal bowl. If the water directly strikes the top of the bowl, the bowl gets hotter, whereas if the water comes in at an angle, the bowl doesn't get as hot. This wasn't a bad example and relates to the directness of the sun's rays on Earth's surface! However, the student used a few words that would confuse an 8 year old. For example, he used the word 'particle' and 'directness of sunlight'. These terms make sense to us in the class, but may not to an 8 year old.
The goal of this exercise wasn't to be perfect, but to attempt an explanation to a very general audience without much of a science background. It's much harder than it looks and you encounter problems you didn't necessarily expect to encounter. It's a task all of us should take on from time to time to continue that relationship with a non-expert in your chosen field. Try it on your kids. Try explaining what you do at work in a way they'll understand. It's hard, but a worthwhile experience as a parent.