Then Fujii looked closer. The beams were synchronized with a tiny green dot that was briefly visible between the clouds. He guessed it was a satellite, so he investigated orbital data and got a match. NASA's Ice, Cloud and Land Elevation Satellite 2, or ICESat-2, had flown overhead that night. Fujii posted his findings on social media, which eventually got the attention of the NASA team.
It's the first time the ICESat-2 team has seen footage of the satellite's green laser beams streaming from orbit to Earth, said Tony Martino, ICESat-2 instrument scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
"ICESat-2 appeared to be almost directly overhead of him, with the beam hitting the low clouds at an angle," Martino said. "To see the laser, you have to be in the exact right place, at the right time, and you have to have the right conditions."
ICESat-2 was launched in September 2018 with a mission to use laser light to measure the height of Earth's ice, water, and land surfaces from space. The laser instrument, called a lidar, fires 10,000 times a second, sending six beams of light to Earth. It precisely times how long it takes individual photons to bounce off the surface and return to the satellite. Computer programs use these measurements to calculate ice losses from Greenland and Antarctica, observe how much of the polar oceans are frozen, determine the heights of freshwater reservoirs, map shallow coastal regions, and more.
Fired from hundreds of miles up in space, the laser light is not harmful. In fact, it's tricky to spot. If someone stood directly under the satellite and looked up, the laser would have the strength of a camera flash more than 100 yards away, Martino said.
People have tried to photograph the satellite when it passed over, and in a couple instances they were able to capture photos - once from southern Chile and once from Oklahoma.
The beam is even more difficult to capture, he noted, since cameras and eyes need the laser light to reflect off something to see the beam from the side. That's where the atmospheric conditions come in.
On the night ICESat-2 passed over Fuji City, however, there were enough clouds to scatter the laser light - making it visible to the cameras - but not so many clouds that they blocked the light altogether. There were actually two thin layers of clouds over Japan that night - information Martino found by analyzing the ICESat-2 data, which shows clouds as well as the ground below.
With the precise location of the satellite in space, the location of where the beam hit, the coordinates of where Fujii's cameras were set up, and the addition of cloudy conditions, Martino was able to confirm, definitively, that the streaks of light came from ICESat-2's laser.
|Subscribe Free To Our Daily Newsletters|
Russian cosmonauts take spacewalk outside of ISS
Space seeds take root in Inner Mongolia
Calnetix Technologies' high-speed blower system installed on ISS
Rocket Lab launches new constellation-class star tracker
Rocket Lab introduces suborbital testbed rocket, selected for hypersonic test flights
Elon Musk forms X.AI artificial intelligence company
SpaceX reschedules Starship test flight for Thursday
Southern Launch to partner with Koonibba aboriginal community to develop spaceport
Clouds Above, Contact Science Below: Sols 3800-3802
Hey Percy, look at those boulders
Curiosity gets a major software upgrade
Ingenuity Mars Helicopter completes 50th flight
China, France join hands in space
Shenzhou XV mission crew members set China record
Spacewalks become 'routine' after 12th mission
Rocket that will carry Tianzhou ship to space arrives at launch center
Viasat confirms ViaSat-3 Americas set to launch|
Virgin Orbit bankruptcy: why the UK's spaceport industry may still have a bright future
Nova Space to offer Space Professional Development Program for AWS Employees
HawkEye 360's latest Cluster 7 satellites successfully launched
NASA satellite's elusive green lasers spotted at work
General Atomics completes commissioning of space environmental testing chambers
SwRI joins new NASA institute to qualify, certify additive manufacturing methods
Viasat real-time Earth antennas integrated on Microsoft Azure Orbital
International team discover new exoplanet partly using direct imaging
Webb peeks into the birthplaces of exoplanets
HD 169142 b, the third protoplanet confirmed to date
Do Earth-like exoplanets have magnetic fields
Icy Moonquakes: Surface Shaking Could Trigger Landslides
Europe's Jupiter probe launched
Europe's JUICE mission blasts off towards Jupiter's icy moons
Spotlight on Ganymede, Juice's primary target
|Subscribe Free To Our Daily Newsletters|