On clear summer days, if you have a clear and flat horizon, you can see Earth's shadow right after the sun goes down or right before it rises in the morning.
Location: Keota Star Party, CO
Camera: Canon XT
Lens: Sigma 20mm f/1.8
Mount: Still Tripod
Exposure: 23x1/50th second, f/5.6, ISO 400
Processing: PTGui Pro, Photoshop