Comet Hale-Bopp. The bow shock is clearly visible.
The tornado machine at the St. Louis Science Museum.
The big lightning bolt was close enough to light up the tree branches facing it.
Red spotted purple (Limenitis astyanax) or (Basilarchia arthemis astyanax)?
A large model rocket I built as a teen. It was over 6 feet tall.
I built the power supply from the Feburary, 1968 Popular Electronics article, "Experimenter's Short-Proof Power Supply".