3dRose Full Moon Rising - Astronomy - Photography - Key Chains, 2.25 x 4.5 inches, set of 2 (kc_57179_1)

Besides the Sun, the Moon is the most obvious object in the sky. Bright, silvery, with tantalizing features on its face, it’s been the target of imagination, poetry, science, and even the occasional rocket. If you pay even the most cursory attention to it, you’ll see that it changes every day; sometimes it’s up in the day, sometimes at night, and its shape is always changing. What causes this behavior? The Moon is basically a giant ball of rock 3500 kilometers across hanging in space. Its surface is actually pretty dark, with about the same reflectivity as a chalkboard or asphalt. However, it looks bright to us because it’s sitting in full sunlight; the Sun illuminates it, and it reflects that light down to us here on Earth. And because it’s a sphere, and orbiting the Earth, the way we see it lit by the Sun changes with time. That’s what causes its phases: geometry. The important thing