2010 California contrail incident

On the evening of Monday, November 8, 2010, an unusually conspicuous contrail appeared about 35 miles west of Los Angeles, California in the vicinity of Catalina Island. News footage of the event from a KCBS helicopter led to intense media coverage and speculation about a potential military missile launch, with many reporters and experts discussing the contrail and theorizing about its source.

Coverage continued for several days. The Pentagon released a statement on November 9 that it could not identify the source of the vapor trail, but both the North American Aerospace Defense Command (NORAD) and U.S. Northern Command stated it was not a foreign military launch. On November 9, the FAA also issued a statement that it had not approved any commercial space launches in the area for the prior day. Eventually, on November 10, about 30 hours after the contrail first gained press attention, a Pentagon spokesman stated there was no evidence to suggest the plume was anything but an aircraft contrail. Some experts, however, held that the vapor trail could not be identified as an aircraft contrail with total certainty, and others stated it was a missile.

While some uncertainty over the contrail's origin persisted, the incident came to be seen as an example of news outlets being "captives of their sources" and irresponsibly pushing unverified theses; it was also interpreted as a lesson in the importance of exploring alternative hypotheses that fit available data. U.S. federal and military authorities were also criticized for giving a series of "inconclusive" answers about the event and allowing the issue, in the words of one commentator, to "fester for days" without a clear resolution.

Background
Contrails, short for "condensation trails," are linear cloud formations produced by aircraft exhaust or air pressure changes, usually at commercial cruising altitudes several miles above the ground. Contrails may last for mere minutes, or may last for hours and expand to several miles across, coming to resemble naturally-formed cirrus or altocumulus clouds. A contrail from an airplane flying towards an observer can create the illusion of a vertically moving object, as happened with a contrail off the coast of San Clemente, California on December 31, 2009, which some observers mistook for a missile launch. The San Clemente "New Year's Eve Contrail" was a horizontal trail at about 32,000 feet, or six miles, in altitude, that appeared to be oriented vertically due to the ground-level perspective from which it was observed and photographed. There are also historic examples of observers confusing aircraft contrails for other phenomena, especially when contrails were still uncommon, including incidents in Galveston, Texas on October 27, 1951; in several areas of Iowa on April 15, 1950; and throughout the San Francisco Peninsula on January 11, 1950, when a B-50 Superfortress bomber flying at 35,000 feet caused many residents to call police stations to report a "burning plane," "meteors," and "flying saucers." While a number of experts concluded the 2010 California event was simply a common aircraft contrail, some experts held that while an airplane was the most likely cause a missile launch could not be totally ruled out based on the existing evidence. San Nicolas Island, approximately 75 miles west of Los Angeles and the site of a U.S. military installation, has hosted a number of secret operations. The 2010 incident occurred not far from San Nicolas, leading some experts to speculate about a connection between the contrail and activity on the island. On Friday, November 5, 2010, several days prior to the contrail incident, Vandenberg Air Force Base launched a Delta II rocket carrying a Thales Alenia Space-Italia COSMO SkyMed satellite, but a sergeant from Vandenberg informed CBS News 8 that there had been no subsequent launches.

Incident and response
At around 5:00 PM Pacific Time on Monday, November 8, 2010, a news helicopter from the KCBS station recorded the vapor trail of what was described as a "missile" traveling 35 miles (56 kilometres) west of Los Angeles, California and somewhat north of Catalina Island. It was later characterized as a "large vertical column set against the bright orange sky at sunset" and was clearly visible from the Los Angeles area. Scott Diener, the news director at KCBS, stated that the experts interviewed by his station on "Tuesday night and Wednesday morning had leaned toward the missile theory" to explain the origin of the plume. News anchors continued to cover the event and, by the end of Tuesday, it had attracted international press attention, being described as a "mystery missile" or "vapor trail reminiscent of a missile launch."

Several experts argued that the plume was simply a jet contrail, yet others disagreed, and U.S. government sources did not immediately reach a public conclusion about the vapor trail or its source. Pentagon spokesman Colonel David Lapan said that any missile test in the area was "implausible" due to the close proximity of the sighting to Los Angeles International Airport. Col. Lapan also stated that were no known airspace closures or notifications to mariners at the time of the incident as would be expected for a missile test. Robert Ellsworth, former U.S. Ambassador to NATO and former Deputy Secretary of Defense, stated to CBS News 8 that it did not appear to be a Tomahawk missile but, stressing it was only a theory, also remarked: "It could be a test firing of an intercontinental ballistic missile from an underwater submarine, to demonstrate mainly to Asia, that we can do that." Ellsworth further said of the vapor trail: "It's spectacular...It takes people's breath away," and described the projectile as "a big missile." Doug Richardson, editor of Jane's Missiles and Rockets, said: "It's a solid propellant missile, you can tell from the efflux [smoke] but they're not showing enough of the tape to show whether it's staging [jettisoning its sections]." Richardson theorized it might be a standard interceptor missile of the type used by U.S. Navy Aegis guided-missile cruisers. The United States Northern Command and the North American Aerospace Defense Command released a statement in response to the sighting, saying, "At this time, we can confirm that there is no threat to our nation and from all indications this was not a launch by a foreign military." The Pentagon released a statement on November 9 declaring that it could not identify the source of the vapor trail. Col. Lapan stated that officials were "still trying to find out what the contrail off the coast of southern California was caused by," but that currently, "all indications are that it was not a DoD activity." The Pentagon determined that there was no "scheduled or inadvertent" missile launches off the coast of California on the night of November 8. Adm. Gary Roughead, Chief of Naval Operations, stated to The Washington Post that it "wasn't a Navy missile," yet declined to offer more detail.

The website ContrailScience.com produced a widely circulated report that explained how an airplane contrail moving directly toward a viewer has the appearance of rising vertically. The website referenced the December 31, 2009 San Clemente "New Year's Eve Contrail," a horizontal contrail which some observers believed was a vertical missile launch, in their explanation of the new incident. John E. Pike, the director of GlobalSecurity.org, stated that the flying object producing the vapor trail was not a missile because it was too slow, and described it as "obviously an airplane contrail." On Tuesday, Pike said that what the KCBS crew recorded was "clearly an airplane contrail. It's an optical illusion that looks like it's going up, whereas in reality it's going towards the camera. The tip of the contrail is moving far too slowly to be a rocket. When it's illuminated by the sunset, you can see hundreds of miles of it...all the way to the horizon." Light at the head of the contrail that was initially speculated to be an exhaust "flame" was later explained as sun reflecting from an aircraft exterior. As reported on November 10, an unnamed official from the U.S. Northern Command stated the vapor trail may have been caused by a plane, and likened it to observers mistaking the New Year's Eve contrail for a missile. FAA spokesman Ian Gregor stated: "The FAA ran radar replays of a large area west of Los Angeles based on media reports of the possible missile launch at approximately 5 p.m. (PT) on Monday. The radar replays did not reveal any fast moving, unidentified targets in that area...The FAA did not receive reports...of unusual sightings from pilots who were flying in the area on Monday afternoon." Eventually, on November 10, about 30 hours after the contrail first gained press attention, a Pentagon spokesman stated “there is no evidence to suggest that this is anything else other than a condensation trail from an aircraft.” U.S. Airways flight 808 from Honolulu, Hawaii—a Boeing 757-200—emerged as a candidate for the contrail's source. UPS flight 902—a McDonnell Douglas/Boeing MD-11—was also raised as a possibility. Many reporters eventually concluded that the "missile" was a simple airplane contrail or optical illusion, as several experts had already argued. At the time, the public and news reaction to the event was characterized by one outlet as the "mystery missile mania." Nonetheless, some experts continued to hold that the vapor plume could not be conclusively identified. In a November 14, 2010 article, The New York Times quoted Theodore A. Postol, a former Pentagon science adviser and professor at the Massachusetts Institute of Technology, who stated that while he inclined to the jet explanation, he could not "rule out a missile launch." On November 16, Space.com published an article discussing an image taken by the NASA/NOAA GOES 11 satellite on November 8 that reportedly showed the "mystery" contrail visible as a "horizontal white streak." The NASA website itself also discussed the GOES 11 imagery in an article. Patrick Minnis, a contrail expert in the Science Directorate at the NASA Langley Research Center, said he first "assumed it was a missile" but after research concluded that an aircraft was the "most likely" source of the contrail.