With summer just around the corner, the WSU Insider dug into the Ask Dr. Universe archives for a 2020 piece answering a question from a curious 9-year-old about why we have different seasons each year.

The fictional feline Dr. Universe sat down with her friend Vivienne Baldassare, a physics and astronomy professor at Washington State University, to find out exactly why we have seasons.

Baldassare explained while Earth orbits the Sun, the planet itself is also spinning around like a top. But it doesn’t spin straight up and down; it’s actually a little bit titled.

It’s this  tilt that gives us our seasons. The tilt also means sometimes the North Pole will be pointing closer to the Sun, while the South Pole will be pointing farther away from the Sun.

When the Earth is in this position, it will be spring or summer on the Palouse and across the rest of the Northern Hemisphere—the top half of the planet. But in the Southern Hemisphere—the bottom half of the planet—it will be fall or winter.

Visit the Ask Dr. Universe website for answers to more questions from curious elementary and middle school students.