Why do unidentified objects seem to be popping up above North America all of a sudden?

The appearance of a series of unknown objects in the sky during the week that were shot down has raised the question of why things are happening like this. Since February 4, when US military personnel shot down a Chinese spy balloon off the coast of South Carolina, three more objects have been shot out of the sky in eight days.

So far, only the first object shot down has been identified as a Chinese spy balloon. The US military said on Monday it had recovered a key sensor from the wreckage.

Other objects, according to John Kirby, the US National Security Council’s coordinator for strategic communications, have no propulsion and are not maneuverable. That’s why the U.S. isn’t sure if “they have a surveillance aspect to them,” he said.

However, Prime Minister Justin Trudeau said there was reason to believe it was not a coincidence that the four objects appeared within such a short period of time.

“Obviously, there are some patterns there,” he said. “The fact that we saw this at a significant level during the last week is a cause of interest and close attention, which is what we are doing.”

CBC Explains that more objects are appearing in North American skies, why they’re so hard to detect and what they’re doing to make them easier to find:

Are more unidentified objects appearing in the skies over the US and Canada lately?

It’s harder to say that there are more unidentified objects hovering over the US and Canada than ever before.

Thomas Lawson, the former chief of defense staff who was also deputy commander of NORAD from 2011 to 2012, told CBC News Network that when he was at NORAD, he had “no indication …

“I think it’s great that the NORAD commander has now evaluated some of that [unidentified objects] The last few years have now been determined to fly on the North American continent,” he said.

However, as Kirby notes, for years, there have been “unexplained aerial phenomena” reported without explanation or in-depth investigation by previous governments.

“Finally we’re trying to get a better understanding now of the Chinese balloon program and this new attack on our airspace,” he said at a press conference on Monday.

The White House acknowledged that there had been at least three incidents of balloons flying over US territory during the Trump administration, and one during the Biden presidency, before last week’s discovery.

“This is assessed as part of a larger Chinese surveillance balloon program,” Brig-Gen. Patrick S. Ryder, Pentagon spokesman, said at a news conference last week. “What we do know is that in some cases, while some of these balloons were previously unidentified, subsequent analysis, subsequent intelligence analysis allowed us to show that these were Chinese balloons.”

Why are officials seeing more unidentified objects than ever before?

Since the US shot down a suspected spy balloon from China on February 4, there has been closer surveillance of airspace, Melissa Dalton, assistant secretary of defense for homeland defense and hemispheric affairs, said at a press conference last week.

This includes improving the North American Air Defense Command (NORAD) radar which, Dalton said, could at least explain the increase in detected objects.

“One of the reasons we’re thinking more is because we’re looking for more,” Kirby said. “If you set the parameters in such a way to search for something, it is more likely that you will find something specific.”

Riki M. Ellison, chairman and founder of the Missile Defense Advocacy Alliance, said he believes past administrations “tolerated” the object flying in airspace.

“Last week, they decided not to tolerate it anymore,” he told CBC News in a phone interview.

Why is it difficult to detect these objects?

For those assigned to look at the radar screen, it can be “overwhelming … with all the radar data coming at them,” retired major general Scott Clancy, who at one time was deputy commander of the Alaskan NORAD Region, told CBC News Network.

“When your main threat is an airplane traveling at hundreds of miles per hour, you adjust the gain or filter to a level so that you focus on that threat,” he said.

And with so many gaps in Alaska’s radar system and without the right sensors to detect objects like spy balloons, it’s like chasing a “needle in a haystack,” Ellison said.

That’s because slow-moving objects, such as balloons, at high altitudes are difficult to detect on radar, Kirby said.

“Even an object the size of a Chinese spy balloon with a payload the size of about three school buses was not picked up by the previous administration or any other country,” he said.

Another problem is the temperature of the balloon itself. Slow-moving balloons don’t give off detectable heat at long distances, Ian Williams, deputy director of CSIS’s Missile Defense Project, told Time magazine.

“They are not warm, usually. They kind of assume the temperature of the surrounding air for the most part; they don’t have a burning engine or something like that,” He said.

What does NORAD do to find unidentified objects?

General Glen VanHerck, commander of NORAD, said the radar can be set to filter “low speed” and latitude, but that has since been adjusted to “give us more fidelity in seeing small objects.”

“So, with some adjustments, we have been able to achieve a better categorization of radar tracks now,” he said. “And that’s why I think you see this as a whole. In addition, there is a higher alert for this information,” he told reporters during a briefing at the Pentagon last week.

Ellison said that they took down the first object, which set a precedent that allowed NORAD to better calibrate the sensors to start looking for patterns, and to look for certain types of objects.

“I already know what the pattern is now, where it’s happening and what it’s targeting,” he said. “That’s why you see more objects being removed.”