‘Little Green Men’ SETI signal in 1967 focus of new scientific paper

A recent paper in the European Physical Journal highlights a case in 1967 in which mysterious radio signals were discovered by radio astronomers. The possibility of the signals being of extraterrestrial origins caused the astronomers to seriously consider how they would release the information to the public, or if it would be best to bury the information in fear of the temptation to contact potentially hostile ETs. In fact, they were so intrigued by the idea of the signal being ET in origin they dubbed it the LGM signal for “little green men.”

The LGM case was unique in that it sparked discussion amongst SETI scientist to set protocols for how to release the discovery of potential ET signals to the public, and how to verify they are indeed ET in origin. It was also unique in that although the signals were mysterious and lead to an important discovery, the discovery was not of a message from extraterrestrials, but instead the group had discovered pulsars for the first time.

The paper, titled, The SETI Episode in the 1967 Discovery of Pulsars, is authored by Alan Penny from the School of Physics and Astronomy at the University of St. Andrews in Scotland. In the abstract, Penny writes, “Although their investigations lead them to a natural explanation (they had discovered pulsars), they had discussed the implications if it was indeed an artificial source: how to verify such a conclusion and how to announce it, and whether such a discovery might be dangerous.”

Jocelyn Bell and the radio telescope used to discover the LGM signal.

The LGM signals in question were received in the winter of 1967 by radio astronomers at the University of Cambridge. One of the graduate students who worked on the project, Jocelyn Bell, was the first to discover the signals. According to Discovery News, one of the reasons it was mysterious is that no signal like it was every recorded before, and it “mimicked the signature of manmade radar transmissions.” Bell wrote in her thesis, “The possibility that the signals were from some intelligent civilization in the universe was not ruled out: hence the unfortunate nickname ‘little green men’.”

Another group member, John Pilkington said, “We were using the resources that we had to examine a weak and unreliable signal that could have been interference, or equipment malfunction, or a previously unrecognized ‘natural’ phenomenon, or LGM [Little Green Men]. They [LGM] were always a possibility, with awesome implications, but they didn’t really drive the investigation.”

The group leader, Martin Ryle, later wrote how seriously the potential  ET origins of the signal were taken when he wrote, “Our first idea was that other intelligent beings were trying to establish contact with us.” He goes on to say that, in the beginning, their investigation began producing data that supported the ET hypothesis.

Facing these extraordinary possibilities, they first felt it was important not to leak their suspicions. They felt the ensuing media frenzy would hamper their research. The scientists in the office next door didn’t even hear of their discovery, or their consideration of the idea that they had discovered the first extraterrestrial “Hello”, until their paper came out. Meanwhile, the scientist wrestled with who to contact, how, or even if. Ryle was very concerned with the implications of contacting an ET civilization. In fact, he had written to Frank Drake, after Drake had sent a signal to space, warning it could be “very hazardous to reveal our existence and location to the Galaxy; for all we know, any creatures out there might be malevolent – or hungry.” So the group had seriously considered keeping their discovery secret so that no other scientist would be as fool hardy as Drake and possibly endanger the planet.

After keeping the signal under their hat for several weeks, and seeking verification, the team eventually discovered that the LGM signal was actually an astronomical phenomenon, and this lead to the LGM actually being the first detection of pulsars. Although this wasn’t an extraterrestrial signal, it did inspire the creation of SETI protocols on how to deal with the discovery of actual ET signals.

Alan Penny (credit: University of St. Andrews)

Penny writes:

This episode is an early ‘real-life’ example of dealing with concerns of subsequent SETI work: how to test and confirm a SETI discovery, how to announce it, and whether sending a message out is dangerous. The process they went through remarkably presages many aspects of that codified by the SETI community team 23 years later in the ‘SETI Detection Protocols’ (IAA SETI Group 1990) and 37 years later in proposals (IAA SETI Group 2004) for dealing with sending signals out in the ’Proposed SETI Reply Protocols’.

You can download Penny’s paper here: The SETI Episode in the 1967 Discovery of Pulsars

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