Senior military officers and civilian advisers within the US Department of Defense (DoD) say the recent rash of unidentified object discoveries may be the result of new settings applied to airspace monitoring radars.

Pentagon officials, including the commander of North American Aerospace Defense Command (NORAD), said on 12 February the USA and Canada increased the sensitivity settings of their radar network, following a multi-day incursion into US and Canadian airspace by a Chinese surveillance balloon during the first week of February.

radar

Source: US Air Force

A US Air Force AN/TPS 75 aerospace control and warning radar site at an undisclosed location in southwest Asia

“Radars essentially filter out information based on speed,” says NORAD commander General Glen VanHerck. “You can set various… velocity gates that allow us to filter out low-speed clutter.”

VanHerck adds there are additional filters for an object’s size and altitude – all intended to keep benign objects like wildlife or clouds from triggering alerts.

However, in the aftermath of the Chinese balloon incident, NORAD has adjusted those gates to report objects previously filtered out.

“With some adjustments, we’ve been able to get a better a categorisation of radar tracks now,” VanHerck says. “And that’s why I think you’re seeing these [incidents] overall.”

Undersecretary of defense Melissa Dalton confirms Washington has been “more-closely scrutinising our airspace” at these altitudes, including “enhancing our radar, which may at least partly explain the increase in objects that we’ve detected over the past week”.

In the week following the balloon incident, three objects have been detected and shot down over the USA and Canada – one off the coast of Alaska on 10 February, a second over Canada’s Yukon Territory on 11 February and a third on 12 February near the two countries’ border on Lake Huron. Defence officials have revealed little about the objects’ characteristics.

“I believe this is the first time within [US] airspace that NORAD or United States Northern Command has taken kinetic action against an airborne object,” VanHerck notes of the recent events.

US Air Force (USAF) Lockheed Martin F-22 stealth fighters carried out the first two shoot downs, in addition to the 4 February downing of the Chinese balloon. A Lockheed F-16 from the Air National Guard downed the 12 February object.

When it comes to the size of the objects, VanHerck notes they are “very, very small objects that produce a very, very low radar cross-section”. He declines to address the shape of the objects, noting observations have been difficult for the pilots.

Various sources in the US and Canadian governments have reported the objects as being cylindrical or octagonal in shape, but that remains unconfirmed by NORAD and the Pentagon.

In each case, Raytheon AIM-9X Sidewinder heat-seeking missiles destroyed the targets. VanHerck says the objects’ minimal radar cross-section made using a radar-guided missile a riskier option. He adds pilots in both the 12 February and 11 February incident evaluated taking a shot with their aircraft’s unguided cannon.

“The pilots in each situation felt that that was really unachievable because of the size… and also because of the challenge to acquire it visually because it’s so small,” he says.

While the Pentagon is not speculating on what the objects are, VanHerck notes they are travelling “very slow”.

“These are… going at the speed of the wind essentially,” he says.

Notably, Washington has pointedly refrained from describing the recent three objects as malicious activity by Beijing.

“We have not yet been able to definitively assess what these recent objects are”, says Dalton. “The spy balloon from [China] was of course different in that we knew precisely what it was”.

148th wing f-16s

Source: Minnesota National Guard

F-16s from the 148th Fighter Wing, which responded to and shot down an unknown airborne object over Lake Huron on 12 February

Defence officials reiterate that none of the objects, including the Chinese balloon, posed what they describe as a “kinetic” threat to the USA.

However, unlike the surveillance balloon – which was operating above altitudes used by commercial aircraft – the unidentified objects did pose a hazard to regular air traffic. For this reason, the Pentagon says it resorted to force much faster than when downing the balloon.

Dalton notes the small objects may not be sinister activity by a foreign power.

“We also know that a range of entities, including countries, companies [and] research organisations, operate objects at these altitudes for purposes that are not nefarious, including legitimate research,” she says.

The DoD and intelligence agencies have in recent years been paying new attention to rising reports of so-called unidentified aerial phenomena (UAP) by its pilots. A January report produced by the Office of the Director of National Intelligence (ODNI) says there have been 247 new UAP sightings reported by American aviators since 2021.

Of the reports analysed, 163 were ultimately determined to be balloons or “balloon-like entities”. VanHerck notes NORAD has previously scrambled fighters for radar contacts that turned out to be birds or weather events.

However, an unspecified number of reported UAP sightings have drawn additional scrutiny from senior officials based on their observed behaviour.

“Some of these uncharacterised UAP appear to have demonstrated unusual flight characteristics or performance capabilities,” the ODNI report says.

Defence officials say they are taking the UAP issue seriously and have sought to de-stigmatise filing such reports, for which pilots may have been judged negatively in the past.

VanHerck declines to characterise the recently destroyed UAPs as balloons, saying the DoD does not yet know what type of craft they were.

“I am not able to categorise how they stay aloft,” he said following the third shoot-down on 12 February. “It could be a gaseous type of balloon inside a structure or it could be some type of a propulsion system.”

“But clearly, they’re able to stay aloft,” he adds.

Speaking following the latest incident, VanHerck was specifically asked about the possibility the recent UAPs being extraterrestrial in origin. The NORAD commander, himself a Boeing F-15 and Northrop Grumman B-2 pilot, notes intelligence agencies are taking the lead on identifying the objects based on efforts to recover wreckage.

“I haven’t ruled out anything,” he adds.

The White House was more definitive on the possibility of extraterrestrial activity. John Kirby, who oversees public communications for President Joe Biden’s National Security Council, on 13 February downplayed any otherworldly explanation for the recent aerial activity.

“I don’t think the American people need to worry about aliens,” Kirby says.