MYSTERY WIRE — Between 1949 and 1951 the U.S. Air Force ran a program called Project Twinkle to lean more about mysterious light phenomena being seen by military personnel mainly in the southwestern United States and often near or over sensitive military sites.

Project Twinkle also involved looking into reports of green fireballs being seen in the sky.

Project Twinkle was actually part of another classified program called Project Grudge. Grudge was also a U.S. Air Force project to investigate UFOs that began in 1949 through 1951. Grudge came after Project Sign, a similar program that ran from 1947 – 1949.

Projects Twinkle, Grudge, and Sign were all precursors to Project Blue Book.

In the Project Twinkle documents (below), light phenomena is documented above and near several military facilities. Many of the reports focus on the southwestern states. Some reports describe multiple people seeing green and other colored lights, or fireballs, in the sky.

Some had the characteristics of meteors, but others were described as being able to stop and start.

But in the final Project Twinkle report, the government concluded most of the observed light phenomena could be “attributed to such man-made objects as airplanes, balloons, rockets, etc. Others can be attributed to natural phenomena such as flying birds, small clouds, and meteorites.”

The final report also stated “There has been no indication that even the somewhat strange observations often called “Green Fireballs” are anything but natural phenomena.”

Below you can read the final report on Project Twinkle and find links to other now-unclassified government documents on Project Twinkle and Project Grudge.

Project Twinkle Documents

Mystery Wire Documents