Green Fireballs???

[guohua]

Yes, they were called Green Fireballs and there were numerous sighting in the 40's & 50's.
Here is a Thread Thanks To @"Mystic Wanderer" & @"OmegaLogos" .

Why Mysterious Green Fireballs Worried the U.S. Government in 1948
The sightings were concentrated around the Los Alamos and Sandia atomic-weapons laboratories, and other highly sensitive military installations.

Green Fireballs NOT Big Green Furry Balls. 

On February 29, 1949, the Los Alamos, New Mexico Skyliner newspaper ran a piece on what it referred to, in typical newspaper parlance, as “flying saucers”—and a possible conspiracy around them:

“Los Alamos now has flying green lights.
These will ‘o wisps seen generally about 2 a.m., have alerted the local constabulary and their presence is being talked about in Santa Fe bars. But local wheels deny any official knowledge of the sky phenomena. Each one passes the buck to another.”

The story ended with, “Have you seen a green light lately?”

In fact, a great many had, and would continue to do so—enough to prompt TIME magazine, in November 1951, to publish a piece on the phenomenon called “Great Balls of Fire.” What makes the multiple sightings of “flying green lights” in New Mexico in 1948 and onward such a significant chapter in UFO history is exactly that—there were multiple sightings.
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