Here's an easy science project about the earth and sun.
With your child standing outside in the sun, draw a chalk outline of him/her. Make sure to draw around the feet so your child can step into the same position later.
A few hours later, stand in the footsteps of the drawing and notice how the shadow has changed. The shadow will be in a different place and have a different shape, as I'm sure even the smallest of children will be able predict.
Knowing the outcome of the experiment doesn't take away from the fun of seeing the change happen. The older kids, like mine, and the adults in the workshop enjoyed the project just as much as the little ones (perhaps more).
I learned the chalk project at a workshop I attended with one of my children at the astronomy department at a local college.
The workshop was about the sun, and the instructors gave us special black-out glasses to wear that allowed us to look at the sun directly. Through the filter glasses, the sun looked simply like a bright circle in the dark, but everyone without exception said something like, "Yes! I see it. Wow. It's the sun!"
I guess it's what we all have in common, the sun in the sky.
No matter where we are or who we are, the sun rises every day for each of us, for all of us. Even if we don't pay attention to it, the sun is there. It doesn't matter what we do, the sun is there today and will rise again tomorrow, giving us another morning. It's easy to take something so freely given for granted.
But, like with all the gifts we receive undeserved from God, it feels good deep down inside to notice it, to be thankful, and to feel awe, to say, "Yes! I see it. Wow. It's the sun!"
Truly the light is sweet, and a pleasant thing it is for the eyes to behold the sun. Ecclesiastes 11:7.