Is it true: Phoenix Lights?

There's no solid evidence for it.

Two distinct events on March 13, 1997 over Phoenix: (1) approximately 8:15-8:30 PM, a V-shaped formation of lights moved slowly south from Nevada through Arizona toward Tucson. Witnessed by thousands. (2) approximately 10:00 PM, a row of lights appeared south of Phoenix. A Maryland Air National Guard spokesman attributed the 10:00 PM lights to A-10 flare drops over the Barry M. Goldwater Range (statement reported in July 1997), and Lt. Col. Ed Jones confirmed in 2007 that he flew in the flare-dropping formation. The earlier V-formation has never been officially attributed and no tail numbers or flight logs have been published, but amateur astronomer Mitch Stanley watched each light resolve into a pair on a squarish wing through a 10-inch telescope, and McGaha and Nickell's analysis of amateur video found the lights moving relative to one another, consistent with five separate aircraft (possibly A-10s or T-37 trainers) rather than one solid craft. No physical, radar or instrument evidence of an extraterrestrial craft has been produced (the FAA reported nothing unusual on radar in 1997). The cover-up claim rests on an early Davis-Monthan statement that the base had no planes in the air (its spokesman later said he had meant only the base's own aircraft) and a months-long delay before the flare explanation, not on evidence of concealed hardware. Governor Fife Symington, who mocked the incident at a June 19, 1997 press conference, said in 2007 that he had seen it, that it was bigger than anything he had seen and "felt otherworldly"; he described what he saw, not evidence of what it was.