Great question! Here’s how I’d explain it to a 9-year-old.

**Big idea:** Earth is like a spinning top that is tipped over a little. That tilt gives us seasons — **not** Earth getting closer to or farther from the Sun.

Here’s a simple sketch:

```text
SUNLIGHT  → → → → → →

OUR SUMMER
(North Pole leans toward the Sun)

        N
       /
      🌍   ← sunlight hits us more straight-on
       \
        S


OUR WINTER
(North Pole leans away from the Sun)

        N
         \
          🌍   ← sunlight hits us at a slant
         /
        S
```

In summer, sunlight hits our part of Earth **more directly**, and the days are longer.  
In winter, sunlight hits us **at a slant**, and the days are shorter.

As Earth travels around the Sun, it keeps leaning the same way. So sometimes our half of Earth leans toward the Sun — summer — and sometimes it leans away — winter. The other half of Earth gets the opposite seasons.

```text
             ☀️  SUN

   June: Earth here          December: Earth here
   North leans toward Sun    North leans away from Sun
```

Fun fact: Earth is actually closest to the Sun in January, so being close isn’t what makes summer. The **tilt** is the big reason.

Try this: put a pencil through a ball, tilt the pencil, and shine a flashlight on it. Move the ball around the flashlight while keeping the pencil pointing the same direction. She’ll see which side gets more direct light — that side is having “summer.”