A headline today from New Scientist asks what the sun will look like as a planetary nebula when it begins to die--in about 5 billion years.

Questions that involve billions of years from now can be mind-boggling, but considering what happens in the span of a few hours or through the course of a night is something students of all ages can tackle.

When younger children look up at the sky, both shifts in the appearance of the moon as well as differences in what and how many stars are visible at any given time are opportunities for discussion and a bit of scientific fact that can seem amazing to the youngest of astronomers.

Here are a few Science Buddies science fair project ideas which can help bring the night skies into sharper focus:

• Where Did All the Stars Go? [http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p012.shtml]
  Science Buddies difficulty level 1
• The Moon and the Stars
  [http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p014.shtml ]
  Science Buddies difficulty level 2
• Measuring the Moon
  [http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p013.shtml]
  Science Buddies difficulty level 3
• The Milky Way and Beyond: Globular Clusters
  [http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p016.shtml]
  Science Buddies difficulty level 6

I don't know what was being talked about, but as I cleaned up in the kitchen, I heard a conversation with an 8-year old that resulted in questions about water and electricity and whether or not water can conduct electricity. I think the question had come up as he relayed some cool feature of a character in a game and was challenged about whether or not such a power was possible.

Of course, as adults, we think of things like fallen power lines and rain puddles or the risk of a hair dryer falling in a bathtub. Those are the kinds of warnings I grew up with. Clearly, water can conduct electricity!

It's more complicated than that, of course. Water conducts electricity only if it's contaminated. "Pure" water, in other words, does not. But, for all extents and purposes, the feature in the game was likely feasible, and I still steer clear of hair driers and bathtubs.

This morning, I plugged the search terms into the Science Buddies site to see what projects might come up that would let me demonstrate this concept to a 2nd grader. I didn't find the perfect demonstration for the grade level, but a number of interesting projects for older students exist in the Science Buddies science fair project repository:

• Electrolyte Challenge: Orange Juice vs. Sports Drink [http://www.sciencebuddies.org/science-fair-projects/project_ideas/Chem_p053.shtml]
  Science Buddies' Difficulty Level 7-8
• Solar-Powered Water Desalination
  [http://www.sciencebuddies.org/science-fair-projects/project_ideas/EnvEng_p022.shtml]
  Science Buddies' Difficulty Level 6-7
• Conductance as a Water Quality Measurement
  [http://www.sciencebuddies.org/science-fair-projects/project_ideas/Elec_p011.shtml]
  Science Buddies' Difficulty Level 5

Do you have a favorite project for demonstrating these principles and introducing students of various ages to conductivity?

If you're ready to tackle something related to energy, power, and the environment but want to push the envelope a bit farther than the cool (but maybe not quite cutting-edge-enough-for-you and just a bit ubiquitous) Veggie-Powered Batteries, pull on your rubber gloves, grab a nose-plug (totally optional), and check out the ins and outs of biomass and biogas.

From Trash to Gas: Biomass Energy (grades 6-8) has you roll up your sleeves, fill up some soda bodies, and monitor differences in biogas production. In other words... what waste will inflate the balloon fastest?