Cannonball bomb
Part of Hall of Planet Earth.
Facial coverings and timed-entry ticket reservations continue to be required for Museum entry. See Health and Safety.
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