Why do we sometimes see the moon in the daytime?

I actually find this one really hard to get my head around, but it's one of those fundamental things everybody who lives on Earth should know. Once upon a time this stuff was cutting edge. Cute little ink-smudged newsboys stood on street corners calling, “Earth spins on its axis! Read all about it!”

Okay, maybe I've been watching too many movies. Still, we live on Earth so we should know how it works, especially if we happen to be parents – our kids' first teachers.

The basics are: The Earth spins on its axis, but it also travels around the sun. The moon spins on its own axis too, but more slowly than the Earth does, and it orbits the Earth. The Earth takes a day to spin on its own axis and a year to travel around the sun.

The moon is basically a rock, so it doesn't shine. We see the moon because light from the sun bounces off it. The moon appears to change size and shape because we see different parts of it as it completes its orbit, depending on where the sun is in relation to it. A full moon happens when the sun and moon are at opposite sides of the Earth, so the light from the sun shines directly onto the moon's surface. A new moon happens when the moon is at its closest point to the sun.

The moon is actually often in the sky at some point during the day, but it isn't visible because the light from the sky washes it out, or it might be behind some cloud cover.

So basically, the moon isn't just a magical globe that comes out at night, it's just that's when we see it best because the dark sky contrasts against it. When we see it during the day, that is probably because it is traveling away from the sun, so is brightly lit at that point and in one of its larger phases, and the sky is blue.

Traveling the streets and the avenues

This week's Why is probably more likely to come from the mouth of a curious eight-year-old than a toddler, but it's one of those things that often crosses my mind when I'm driving, but I've never gotten around to finding out the answer. Which is what this blog is all about...

So, why are some streets called streets, some roads or avenues, etc? Is it to do with the width of the street, or the length or shape? 

Next week, no excuses, I will journey this road of knowledge and impart my newfound wisdom.