The Goldilocks Zone

The Goldilocks Zone is the range around a star that’s not too hot or too cold to support liquid water. Liquid water is vital to sustaining life like we have on Earth, so fortunately for us, Earth sits in the Goldilocks Zone.

Consider the alternatives:

• If we lived too close to the sun, we’d roast. The average temperatures on Mercury and Venus are hot enough to boil water (and then some).
• And on Mars, the next planet farther out than Earth, the average temperature sits at -85 degrees F (-65 degrees C)— cold enough to freeze water solid.

If you want to look for planets that might support life as we know it in distant star systems, looking for worlds occupying Goldilocks Zones is a promising start.

This sketch, along with plenty of others in the "Starry-Eyed Surprises" section, features in my book Big Ideas Little Pictures

Also see:

• Goldilocks Tasks
• Seasons
• Know your space objects: comets, asteroids, meteors, meteorites
• The potato radius