Museum curator and Japanese astronomer Daiichi Fujii spotted something irregular last September in several motion-sensing cameras he had installed: three bright green lights across the sky.
Astronomers could soon get warnings when SpaceX satellites threaten their view
After studying the footage and comparing it to orbital data, Fuji found the responsible party: the Ice, Cloud and Earth Satellite 2, or ICESat-2, which flew over Japan that night.
According to Tony Martino, the satellite’s instrument scientist, this is the first time the team has seen footage of the instrument’s laser pulsing in the sky.
“ICESat-2 appears to be almost entirely straightforward [Fujii]Martino at NASA said: launch. “To see a laser, you have to be in exactly the right place, at the right time, and you have to have the right conditions.”
ICESat-2 It was launched in 2018 and is used to measure the height of Earth’s surfaces. It basically depends on space lidar scannersimilar to those used by archaeologists for Discover ancient sites lost to natural features such as forest growth.
The video was captured on September 16, 2022. It shows three streaks of light streaking across the sky against a background of scattering clouds. Upon further scrutiny, Fuji realized that the green lines pulsated in time with a light that appeared briefly among the clouds (just above the center of the video frame, if you want to identify it yourself).
Guessing it was a satellite, Fuji checked the spacecraft that had been flying over the cameras that night. And lo and behold, ICESat-2 appears to be the likely culprit.
To show the other side of the encounter, NASA has released the ICESat-2 perspective of Japan. The data chart shows satellite measurement of cloud layers over Japan as well as the country’s topography.
According to NASA, the ICESat-2 rocket is launched at a rate of 10,000 times per second. The satellite has been imaged from Earth before, but not its laser pulses, which require unique atmospheric conditions to be observed.
The clouds over the Hiratsuka City Museum that night scattered the laser light enough to make it visible to the Fuji cameras, but there weren’t many clouds to block the light.
So the next time you see a bright light in the sky, it may not be a meteor or aliens. They may just be human tools, keeping track of what is going on on earth.
More: Astronomers gather to stop Starlink and other satellite constellations from destroying the sky
“Infuriatingly humble alcohol fanatic. Unapologetic beer practitioner. Analyst.”