Why do we have seasons?

1. 1

   Zib says

   Earth spins around an invisible line called its axis, and that line is tipped over. As Earth travels around the sun, the axis keeps pointing the same way. So for part of the year, your half of Earth leans towards the sun and gets the most direct sunshine. That's summer. Six months later, your half leans away, and it's winter.

   For ages 8–10
   Hear Zib

   Checked against Why does Earth have seasons? (NOAA)

2. 2

   Isn't summer when we're closest to the sun?

   Earth is actually closest to the sun in January. That's winter in the north, but summer in Australia. Both halves are the same distance from the sun on the same day, yet they have opposite seasons. So the lean is what makes the seasons.

   For ages 9–11
   Hear Zib

   Checked against What causes the seasons? (NASA Space Place)

3. 3

   Why does leaning towards the sun make it warmer?

   Shine a torch straight down for a small, bright spot. Tilt it, and the same light spreads into a bigger, dimmer patch. Sunlight works the same way. When your half leans towards the sun, the light hits more head-on, so each bit of ground gets more. When it leans away, the light comes in at a slant and spreads thin.

   For ages 10–11
   Hear Zib

   Checked against Climate and Earth's energy budget (NASA Earth Observatory)

In Lil' Phil, reaching the bottom of this wonder earns a sticker for Zib's collection.

• 

  How long is a day, and how long is a year?

  Ages 8–11Zib
• 

  Why do the planets go around the sun?

  Ages 8–11Zib