Yeah I saw one with my cousin back in 72'.
A no moon, clear night at 12-13,000 feet in Yosemite, Tuolumne meadows where we had been backpacking for 2 weeks.
So many Satellites at that elevation you could see, it was amazing.
Every 10 seconds we would see a new one.
A few hours of star gazing and talking and then it happened. The 3 lights in a triangle.
It went back and forth 3 times faster than a jet but slower than a shooting star.
Whatever it was, I won't forget it!
Carbon and water are flying all over in asteroids and meteors.
Life will find a way to start.
Years later, a UFO show claimed it it the most commonly seen UFO appearance.