Space lasers are not just the domain of -- they can help scientists map the Earth too.
On Saturday, will launch the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) into orbit, which carries a giant space laser known as the Advanced Topographic Laser Altimeter System (). That's a lot of acronyms.
ATLAS will enable NASA to create detailed pictures of the planet as the satellite zooms overhead. Every second, the six-beam laser will fire 10,000 pulses from space at the Earth and then record how long it takes until the laser pulse bounces off the land. Around 20 trillion photons leave ATLAS with every pulse and by measuring the travel time for a photon to leave the laser and return, scientists will get incredibly accurate measurements on the height of the planet's features.
The technology will enable scientists to describe the features of the Earth and take accurate measurements of glaciers, ice sheets and sea ice. As ICESat-2 circumnavigates the globe four times a year, researchers will be able to understand how these areas -- prone to climate change -- are tracking as seasons change across the year.
ICESat, which NASA sent to space between 2003 and 2010, collected similar data -- but the technology has come a long way since then. That iteration was only able to fire 40 pulses per second, rather than the 10,000 ICESat-2 can manage, meaning we will get a much more precise picture of Earth's topography.
It's not the first time that a space laser has been fired at the Earth, though. Europe's is currently in orbit above the Earth, undergoing tests to help improve weather forecasting services. A giant space laser (based on the Earth) is also currently helping us , like the Alpha Centauri star system.