Panel #1
• A long time ago = 4.568 billion years. That's how long ago planetary scientists think the solar system formed.
• All objects with mass have gravity. The more mass, the more gravity. So, as things began to grow in size (mass), they had more gravity and were able to attract more stuff.

Panel #2
• The tiniest particles in the early solar system didn't have much mass. If they weren't attracted to a larger mass, they are still the same particles today, spread throughout the space between worlds.


Panel #3
• Gravity caused uncounted collisions, especially early on and close to the Sun where the particle density was highest. As particles stuck together, objects grew in size until several of them became what we call planets.
• A "mosh pit" is an area on the floor of a live music concert (usually punk, hard rock, or heavy metal) where listeners gather to push or slam into each other. Moshing first appeared in the 1980s.

Panel #4
• Our character Sunni is the Sun. It sits at the center of the solar system and is the source of light and heat. Because of its huge gravity, all of the objects in the solar system revolve (orbit) around it. In fact, that's why it's called the solar system: the Latin name for the Sun is Sol.
• The Sun formed the same way the planets did, by objects combining and also by it attracting a lot of the gas that was in the early solar system. The difference between the Sun and the planets is that the Sun became so huge that the temperature at its core (where all its energy comes from) grew to millions of degrees.

Panel #6
• Rocksanne = Mercury; Spark = Venus. Mercury is the planet closest to the Sun, and Venus is second-closest.

Panel #7
• Moonie = The Moon; Tara = Earth. NOTE: Our planet's name is just "Earth," not "the" Earth. We chose "Tara" as the name for our character because the Latin name for Earth is Terra.

Panel #8
• A combination of the Sun's gravity and Earth's speed keeps our planet in its orbit. If Earth weren't moving, it would quickly fall into the Sun. And if the Sun weren't exerting a continuous pull on us, we'd go shooting off into space (in a straight line). Likewise, the Moon revolves around Earth because it's moving at a certain speed and Earth's gravity is pulling it toward us.