The White House is responding to theories that the unidentified objects shot down in recent days could involve visitors from galaxies far far away.

During a Monday press briefing, White House press secretary Karine Jean-Pierre attempted to shut down those rumors saying there’s no sign of visitors from outerspace.

“There is no indication of aliens or terrestrial activity with these recent takedowns,” said Jean-Pierre, who said it was important for the White House to make that clear because they’d been “hearing a lot about it.”

White House officials defended the takedown of three additional objects in recent days after a high-altitude Chinese balloon traveled across the country earlier this month.

The three objects, including one shot down Sunday over Lake Huron, were traveling at such a low altitude as to pose a risk to civilian air traffic, said White House national security spokesman John Kirby. While the Biden administration does not yet have evidence that they were equipped for spying purposes — or even belonged to China — officials have not ruled that out, he said.

“These were decisions based purely and simply on what was in the best interests of the American people,” Kirby said.

On Friday, the North American Aerospace Defense Command, the combined U.S.-Canada organization known as NORAD that provides shared defense of airspace over the two nations, detected and shot down an object near sparsely populated Deadhorse, Alaska.

Later that evening, NORAD detected a second object, flying at a high altitude over Alaska, U.S. officials said. It crossed into Canadian airspace on Saturday and was over the Yukon, a remote territory, when it was ordered shot down by Trudeau.

In both of those incidents, the objects were flying at roughly 40,000 feet. The object on Sunday was flying at about 20,000 feet.

None of the three most recent objects has been recovered, Defense Secretary Lloyd Austin told reporters in Brussels, where he was scheduled to attend a NATO defense ministers meeting this week.

Austin said weather has impeded recovery efforts in Alaska, while in Canada the object was shut down in a very remote area that was also impeding efforts. In Alaska, where the object landed on sea ice, windchill and safety concerns “are dictating recovery timelines,” he said.

The Associated Press contributed to this report.