ICESat-2 will give scientists a clear picture of exactly how polar ice is changing.
Earth’s poles are changing, and as the planet gets warmer the ice will continue to melt. Tracking how that ice changes over the next few years will be crucial for understanding the consequences to the rest of the world. Next month, NASA will launch a new spacecraft to help do just that, equipped with one of the most advanced lasers in the world.
NASA has been sending satellites into orbit to study the poles for a long time. The agency has a number of imaging satellites that can take photos of how the ice changes over time, and the new GRACE satellites, launched just last month, record tiny gravitational fluctuations to spot the changing mass of ice beneath the surface.
NASA’s new Ice, Cloud and land Elevation Satellite-2 (ICESat-2) takes a different approach, by sending a powerful laser into space. Onboard the satellite is the Advanced Topographic Laser Altimeter System (ATLAS), which is designed to measure the exact height of Arctic ice.
ATLAS sends a laser beam from orbit straight down onto the polar ice. When that laser hits the ice, some of the light is reflected back into space, where it’s detected by the ICESat-2 satellite. The satellite measures the time it takes that light to travel down to the planet and come back again down to a billionth of a second.
The ATLAS laser is able to fire around 10,000 times per second as it flies overhead, which means it can make over 2,000 measurements per mile of ground covered. That’s over 50 times more measurements than the previous satellite NASA had in this position, ICESat-1. With that many measurements, ICESat-2 can give scientists a crystal-clear picture of what the polar ice caps look like as they go through one of the most drastic changes in their history.