John Glenn's fireflies

5 declassified cases mention this

• AUD · 1963NASA-UAP-D010, Mercury Atlas 9 Audio Excerpt, May 15, 1963
• AUD · 1963NASA-UAP-D011, Mercury Atlas 9 Audio Excerpt, May 15, 1963
• PDF · 1962NASA-UAP-D015, Astronaut Scientific Debriefings, 1962-1963
• AUD · 1962NASA-UAP-D023, Interview Excerpt with Astronaut Gordon Cooper, 1962
• AUD · 1962NASA-UAP-D012, Mercury Atlas 8 Audio Excerpt, October 3, 1962