Cannonball bomb
Part of Hall of Planet Earth.
All admission to the Museum is by timed-entry, and must be reserved online.
Part of Hall of Planet Earth.
When the bomb hits the ground and hurtles down the slope, making a whirring noise, its corners become sheared, and the hardened form appears as a smooth, rounded lump.
Provided by Lava Beds National Monument and Jeff Dinnel, Tionesta, California