The satellite has 6 beams; the left-most beam in the image is Beam 4, the more powerful beam next to it is Beam 3. The 2 shorter and fainter green streaks in the image are the beams spreading off greater clouds, and the dot that appears next to those faint streaks is the ICESat-2 satellite.
The green light streaking across the cloudy sky was something that Daichi Fujii had actually never seen before. The museum curators motion-detecting video cameras were set up near Japans Mount Fuji to catch meteors, enabling him to calculate their brightness, orbit, and position. But the intense green lines that appeared on a video taken September 16, 2022, were a secret.
Fujii looked better. The beams were integrated with a tiny green dot that was quickly noticeable between the clouds. He thought it was a satellite, so he examined orbital data and got a match. NASAs Ice, Cloud and Land Elevation Satellite 2, or ICESat-2, had actually flown overhead that night. Fujii posted his findings on social media, which ultimately got the attention of the NASA team.
Its the first time the ICESat-2 group has seen video footage of the satellites green laser beams streaming from orbit to Earth, said Tony Martino, ICESat-2 instrument scientist at NASAs Goddard Space Flight Center in Greenbelt, Maryland.
On September 16, 2022, motion-sensing electronic cameras set up by museum curator Daichi Fujii to record meteors instead caught the laser beams of NASAs ICESat-2 satellite as it passed over Japan. Its the very first time the ICESat-2 team has seen video footage of the lasers at work in orbit. Credit: Video Courtesy of Daichi Fujii, Hiratsuka City Museum
” ICESat-2 seemed practically directly overhead of him, with the beam hitting the low clouds at an angle,” Martino said. “To see the laser, you need to remain in the exact right location, at the right time, and you need to have the right conditions.”
ICESat-2 was released in September 2018 with a mission to use laser light to determine the height of Earths water, land, and ice surface areas from space. The laser instrument, called a lidar, fires 10,000 times a second, sending six beams of light to Earth.
As its photo was being taken from the ground, ICESat-2 was at work collecting information on the height profile of the clouds, mountainous surface and ocean of Japan below. This ICESat-2 information plot shows what the satellite determined as it passed over Fuji City, Japan (marked with a vertical green line) on Sept. 16, 2022.
Fired from numerous miles up in space, the laser light is not damaging. Its difficult to spot. If somebody stood straight under the satellite and looked up, the laser would have the strength of a cam flash more than 100 lawns away, Martino stated.
People have actually attempted to photograph the satellite when it passed over, and in a number of circumstances they were able to catch pictures– as soon as from southern Chile and when from Oklahoma.
The beam is much more challenging to capture, he noted, given that eyes and cameras require the laser light to reflect off something to see the beam from the side. Thats where the climatic conditions come in.
On the night ICESat-2 passed over Fuji City, nevertheless, there were enough clouds to scatter the laser light– making it noticeable to the video cameras– however not many clouds that they obstructed the light completely. There were in fact two thin layers of clouds over Japan that night– details Martino found by examining the ICESat-2 data, which shows clouds in addition to the ground listed below.
With the exact area of the satellite in space, the location of where the beam hit, the collaborates of where Fujiis video cameras were set up, and the addition of cloudy conditions, Martino was able to validate, definitively, that the streaks of light originated from ICESat-2s laser.
The satellite has 6 beams; the left-most beam in the image is Beam 4, the more powerful beam next to it is Beam 3. The two much shorter and fainter green streaks in the image are the beams spreading off higher clouds, and the dot that appears next to those faint streaks is the ICESat-2 satellite. The beams were integrated with a tiny green dot that was quickly noticeable in between the clouds. On September 16, 2022, motion-sensing video cameras set up by museum manager Daichi Fujii to capture meteors rather caught the laser beams of NASAs ICESat-2 satellite as it passed over Japan. The laser instrument, called a lidar, fires 10,000 times a second, sending six beams of light to Earth.