Five days before a Chinese spy balloon was spotted over Alaska, a Mauna Kea telescope captured video of a row of green lasers beaming down from space like a picket fence in the cloudy sky above Hawaii island.

Turns out the lasers — first identified as coming from a U.S. orbiting satellite — were likely emanating from a Chinese satellite.

While the incident has added fuel to the alarm surrounding Chinese aerial spying, some say the satellite was probably doing what it was made for: measuring pollutants and other things in the atmosphere.

“I don’t think there’s anything nefarious here,” said astronomer Roy Gal of the University of Hawaii’s Institute for Astronomy. “It’s a known satellite, with a known payload and a known orbit. It’s a scientific satellite. Not everything they launch is for the military.”

A National Astronomical Observatory of Japan video camera atop the Subaru Telescope on Mauna Kea recorded the footage Jan. 28. The ultra-sensitive Subaru-Asahi Star Camera captured the faint laser lights, which are invisible to the naked eye, for just a second.

The lasers were initially believed to be from a NASA altimeter satellite that uses laser pulses to measure the elevation of the Earth’s surface. But the NAOJ corrected itself on Feb. 6, saying NASA scientists “did a simulation of the trajectory of satellites that have a similar instrument and found a most likely candidate as the ACDL instrument by the Chinese Daqi-1/AEMS satellite.”

China’s Daqi-1 satellite was launched in April of last year to monitor global carbon levels and atmospheric pollution, according to the state-owned China Aerospace Science and Technology Corp., which developed the satellite.

Daqi-1 is known to contain five instruments, including ACDL, which stands for Aerosol and Carbon dioxide Detection Lidar.

Lidar is an acronym that stands for laser imaging, detection, and ranging, which uses laser beams to make its measurements. Information on the composition of the atmosphere and the ground below is obtained by the time it takes for the lasers to bounce back to the satellite.

“Daqi-1 can monitor fine particle pollution like PM2.5, pollutant gases including nitrogen dioxide, sulfur dioxide and ozone, as well as carbon dioxide concentration,” a March 2021 press release from the China corporation said.

“China will produce a series of Daqi satellites in the future, which will be used to monitor atmospheric pollution, provide remote sensing data support for environment authorities, and also support scientific research into global climate change,” the March 2021 press release explained.

“It combines both passive and active sensing, which can realize comprehensive monitoring of the atmospheric environment in a better way,” according to a chief designer with the Shanghai Academy of Spaceflight Technology.

The news release goes on to say that the Daqi-1 will work with other satellites, including Daqi-2, to accomplish “greenhouse gas monitoring and help China achieve reduction of carbon emissions.”

Professor Steven Businger of the UH Department of Atmospheric Sciences said the laser technology is a known way to collect data on aerosol concentration and other pollutants.

“We run a laser ceilometer to measure the depth of the mixed layer, the aerosol content, and the cloud base in Pahala, downwind from Kilauea,” Businger said of his research group that helps monitor and forecast vog dispersion across the islands.

Despite the evidence suggesting the laser beams are being used for environmental monitoring, social media and assorted web outlets have been rife with speculation about whether the laser beams are linked to the Chinese military and the spy balloon.

For example, one tweet, by @hodgetwins, which was posted Friday and viewed more than 13 million times, said “China is shining green lasers down to Earth from space from their satellites, this was near Hawaii. This doesn’t seem good.”

According to The New York Times, American officials increasingly believe the Chinese spy balloon that was shot down off the coast of South Carolina in early February was originally supposed to conduct surveillance over U.S. military bases in Guam and Hawaii, but wind carried it off course to Alaska, Canada and finally the continental United States.

The story went on to say at least two spy balloons passed Hawaii previously, one of which drifted over an island quickly and another that entered the airspace around the island chain but did not fly over it.

As for the lasers, similar green beams were captured over Fukushima, Japan, on Dec. 20., according to the Asahi Shimbun. The newspaper said NASA was able to confirm that they were from the same Daqi-1 satellite that likely produced the Hawaii laser beams in late January.

The U.S. Space Force did not respond to an attempt to get a statement about the lasers Wednesday in time for this report.