That dreaded time of the school year is upon us; the time that fills teachers and administrators with angst and causes untold numbers of children to roll their eyes to the sky while sighing, "Do we have to?" The state tests are here again.

Let's try and counter the unease many of us feel and take a fun and stressless quiz of our own. Only three questions and it's not even graded. And there is a bonus! You will be more learned because of it. Ready? Grab your sharpened Number 2 and let's do it.

Question 1: We live in a huge collection of billions of stars. What is it called?

A) The Milky Way
B) The Solar System
C) The Orion Nebula
D) Hollywood, CA

Regular readers here will nail this one instantly. It is the Milky Way, of course. Our galaxy, well over a hundred billion stars strong but organized nicely into a barred spiral shape, is our home.

The solar system is, of course, our local group of planets and debris orbiting the sun. And the Orion Nebula is that star nursery about 1200 light years away in the constellation Orion.

Question 2: What is the origin of our atmosphere's oxygen?

A) Asteroid and comet bombardment
B) Eons of plant life
C) The decomposition of ocean water
D) Walmart

This one isn't so easy but it is keenly important. Bombardment gave us extra rock material to be sure, and is probably responsible for a lot of our water, but not for any significant amount of oxygen. And water itself can break up into hydrogen and oxygen but is definitely not the source of our life-preserving amount of oxygen.

Plant life is the culprit. Early on this planet had essentially no free oxygen. The plants through photosynthesis slowly - and I mean slowly - immersed our planet in the gas. Much was taken by the rocks and oceans but some of it was eventually pumped into the atmosphere, perfectly timed for the arrival of the more complex animal life on land. A miraculous bonus was that some of this oxygen got converted to ozone to protect us from the nasty UV rays from the sun.

Question 3: Why is the liquid magma below us still so hot?

A) Radioactivity
B) The sun warms it.
C) Our magnetic field adds heat to the core.
D) Someone left the iron on.

After 4.5 billion years our insides are still hot as where the devil lives. Why? The big reason is that radioactivity from unstable elements keeps it real hot and the crust traps that heat. Result? We have a molten inside upon which our crust floats. The upshot is that we still have plate tectonics after all these years. Go Earth!

Do well? Of course you did! Until next time, clear skies!