During World War II pilots saw strange, glowing balls of light flying beside their airplanes. They called these lights "foo fighters"

Just after 11 pm on October 1, 2006, six very bright white glowing balls flew in a straight line, one right after the other above the mountains near Cuchara, Colorado. The witness was on his deck at an altitude of 9,100 feet when he saw the baseball-sized objects swiftly floating by.

Researchers have developed a new hand-held device that can produce room-temperature plasmas for diverse applications, most important for biomedical applications.
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At atmospheric pressure, most plasmas are so hot (thousands of degrees centigrade) that they would immediately kill any living cells they come into contact with. Moreover, these high-temperature plasmas are also very difficult to control. In recent years, however, researchers have developed techniques for producing low-temperature plasmas and some of these have been used in biomedical applications.
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When helium gas is injected into the tube and short (less than one microsecond) high-voltage pulses are applied to the electrodes, a discharge is ignited in the gap between the electrodes. This produces a plasma plume that is ejected through the hole in the outer electrode. The plume can be up to 5 centimetres long, with the length depending on the flow rate of the helium and the size of the voltage pulses. The plume remains at room temperature and can be touched by bare hands.

The four-year investigation by the Ministry of Defence (MoD), codenamed Project Condign, looked at the occurrence of Unexplained Aerial Phenomena (UAP) in British airspace. It concluded that many incidents are cause by plasma – ionised gas – which can behave strangely and cause psychological side-effects in human bystanders.

The behaviour of these phenomena is consistent with reports of UAPs that are bright, fast-moving and can change direction with astonishing speed. Furthermore, the report states that plasmas can affect the temporal lobe of the human brain, which could account for the ‘alien experiences’ recounted by self-identified victims of UFO encounters.