(CNN) — It’s been a busy weekend for US fighter jets.

The US military shot down another high altitude object over Lake Huron on Sunday afternoon, the Pentagon said.

Another unidentified object was shot down over northern Canada on Saturday, marking the third time in a week that US fighter jets have taken down objects in North American airspace.

On Friday, an unidentified object was shot down in Alaska airspace by a US F-22.

And last weekend, a Chinese surveillance balloon was taken down by F-22s off the coast of South Carolina.

That marks the beginning and the end of what we know definitively. Here’s everything we still don’t know, and some of the things we do.

Are the latest objects related to China’s spy balloon?

There’s no indication at this point whether the unidentified objects have any connection to China’s surveillance balloon.

Canadian retired Maj. Gen. Scott Clancy, former director of operations at NORAD and former deputy commander of the Alaskan NORAD Region, said on Monday he does not believe China is behind the unidentified objects that have been shot down in recent days. He explained that it could be a “confluence of a distinctive activity by our adversaries to test the systems.”

“It smells to me, as the guy who was directed to conduct operations to defend North America, I’d be very suspicious,” Clancy said on “CNN This Morning.” “And I’d be on high alert to make sure that all of our adversaries are being countered.”

Assistant Secretary of Defense for Homeland Defense and Hemispheric Affairs, Melissa Dalton told reporters on Sunday they were taken down out of an “abundance of caution.”

Dalton said that high-altitude objects can be used by a range of companies, countries, and research organizations for “purposes that are not nefarious, including legitimate research.”

“The spy balloon from the PRC was of course different in that we knew precisely what was,” she said. “These most recent objects do not pose a kinetic military threat, but their path in proximity to sensitive DoD sites, and the altitude that they were flying could be a hazard to civilian aviation and thus raised concerns.”

Are these all balloons?

It’s still unclear, but we’re not dealing with aliens. During a midday briefing on Monday, the White House offered one detail of certainty: the objects did not originate from outer space.

“I just wanted to make sure we address this from the White House: I know there have been questions and concerns about this but there is no — again, no — indication of aliens or extraterrestrial activity with these recent take-downs,” press secretary Karine Jean-Pierre said.

A US official told CNN there has been caution inside the Biden administration on the pilot descriptions of the unidentified objects shot down over Alaska and Canada due to the circumstances in which the objects were viewed.

But at least two high-ranking officials have made reference to balloons.

Senate Majority Leader Chuck Schumer told ABC News that he was briefed on the object by White House national security adviser Jake Sullivan and that the object shot down over Canada was likely another balloon — as was the high-altitude object downed over Alaska on Friday.

Canada’s chief of defense staff, Gen. Wayne Eyre, also made mention of a “balloon” when describing instructions given to the team that worked to take down the object.

Still, deputy Pentagon press secretary Sabrina Singh noted Sunday “these objects shot down on Friday and Saturday were objects and did not closely resemble the PRC balloon. When we can recover the debris, we will have more for you.”

Why are these objects being spotted now?

Notably, the US intelligence community’s method to track China’s fleet of surveillance balloons was only discovered within the last year, six people familiar with the matter told CNN.

The findings have allowed the US to develop a consistent technical method for the first time, which they have used to track the balloons in near-real time across the globe, the sources said.

The revelation that the intelligence community only within the last year developed a reliable way to track China’s balloon fleet — which officials now say has flown dozens of missions worldwide — helps explain why Trump administration officials have stridently claimed to have had no knowledge of the three alleged flights over US territory during the former president’s time in office.

In other words, it’s possible that it’s not so much the objects that are new, but our ability to track them.

And, as CNN’s Natasha Bertrand reported Sunday, NORAD command recently readjusted its filters to better spot slow-moving targets operating above a certain altitude.

“In light of the People’s Republic of China balloon that we took down last Saturday, we have been more closely scrutinizing our airspace at these altitudes, including enhancing our radar, which may at least partly explain the increase in objects that we detected over the past week,” Dalton said.

China has accused the US of “illegally” flying high-altitude balloons into its airspace more than 10 times since January 2022. The White House responded to those claims by saying the allegation is false.

“Any claim that the US government operates surveillance balloons over the PRC is false. It is China that has a high-altitude surveillance balloon program for intelligence collection, that it has used to violate the sovereignty of the US and over 40 countries across 5 continents,” a spokeswoman for the National Security Council, Adrienne Watson, wrote on Twitter.

How large is the Chinese surveillance operation?

It’s still unclear, but it appears to be quite large. Since news broke last week about the Chinese balloon that was floating over US airspace, new details have emerged about what’s now understood to be a global surveillance operation by China’s military, the People’s Liberation Army.

On Thursday, officials revealed that they believe the spy balloons the US has discovered are part of a large fleet that is conducting surveillance operations globally. The US has traced the balloons to 40 countries across five continents.

Lt. Gen. Alexus Grynkewich, the commander of US Air Forces Central, said on Monday Chinese surveillance balloons have been spotted in the Middle East over the last few years. The balloons didn’t fly over Americans bases, Grynkewich said, recalling the latest instance in which a balloon “primarily stayed out over the water.”

Was the object shot down on Sunday like the others?

A US F-16 fighter jet shot down the latest airborne object over Lake Huron on Sunday afternoon at the direction of President Joe Biden, the Pentagon said.

“We did not assess it to be a kinetic military threat to anything on the ground, but assess it was a safety flight hazard and a threat due to its potential surveillance capabilities. Our team will now work to recover the object in an effort to learn more,” Pentagon press secretary Brig. Gen. Pat Ryder said.

The object was flying at 20,000 feet over Michigan’s Upper Peninsula, a senior administration official told CNN on Sunday. It was “octagonal” with strings hanging off and no discernible payload, according to the official and another source briefed on the matter.

CNN reported earlier that Rep. Elissa Slotkin of Michigan said she received a call from the Department of Defense saying the US military “has an extremely close eye” on an object above Lake Huron.

“Just got a call from @DeptofDefense — our military has an extremely close eye on the object above Lake Huron,” Slotkin said in a tweet on Sunday. “We’ll know more about what this was in the coming days, but for now, be assured that all parties have been laser-focused on it from the moment it traversed our waters.”

Unanswered questions

Lawmakers on Capitol Hill want answers. All senators will get a classified briefing Wednesday on China, according to a Senate aide.

This comes after politicians on both sides of the aisle met the news of more objects being shot down with a range of responses Sunday.

House Intelligence Committee Chairman Mike Turner told CNN that the Biden administration does appear “somewhat trigger-happy, although this is certainly preferable to the permissive environment that they showed when the Chinese spy balloon was coming over some of our most sensitive sites.”

“What I think this shows, which is probably more important to our policy discussion here, is that we really have to declare that we’re going to defend our airspace. And then we need to invest,” the Ohio Republican said. “This shows some of the problems and gaps that we have. We need to fill those as soon as possible because we certainly now ascertain there is a threat.”

Turner’s Democratic counterpart on the Intelligence panel, Connecticut Rep. Jim Himes, told NBC’s “Meet the Press” that he had “real concerns about why the administration is not being more forthcoming with everything that it knows,” before adding, “My guess is that there’s just not a lot of information out there to share.”

Schumer, meanwhile, said Congress needs to investigate why it took so long for the US to catch on to the Chinese government’s use of spy balloons.

“I do think (Democratic Sen. Jon) Tester is looking into why it took so long for us, our military, our intelligence, to know about these balloons. That’s something I support. Congress should look at that. That’s the question we have to answer,” he said. “I think our military, our intelligence are doing a great job, present and future. I feel a lot of confidence in what they’re doing. But why, as far back as the Trump administration, did no one know about this?”

Anita Anand, the Canadian defense minister, said on “CNN This Morning” Monday she is “in regular contact” with US Defense Secretary Lloyd Austin after a high-altitude object was shot down over the Yukon on Saturday. When asked if they plan to make the visuals public, Anand said they plan to be “fully transparent,” but did not commit specifically to release visuals. She added the investigation could take some time due to the fact that the debris hasn’t been located yet and fell in a “very remote” part of the Yukon territory.

This story has been updated with additional details.

Here’s everything we still don’t know about the unidentified objects