How big a discovery? How about another Grand Canyon...in Greenland. Seriously.
The newly discovered "mega canyon" is approximately 460 miles (750 kilometers) long, making it longer than the Grand Canyon. In some places, it is 2,600 ft (800 meters) deep, similar to segments of the Grand Canyon.
[By comparison, the Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile (6,000 ft or 1,800 m).]
This huge Greenland feature is thought to have existed before the current ice sheet covered it (i.e., millions of years).
By using thousands of miles of airborne radar information, collected by NASA and researchers from the United Kingdom and Germany over decades, scientists were able to determine the terrain beneath the ice sheet.
They used data collected by NASA's Operation IceBridge, an airborne science program that looks at polar ice. One of IceBridge's scientific instruments, the Multichannel Coherent Radar Depth Sounder, can image and measure the thickness and shape of bedrock beneath huge masses of ice.
Announced yesterday, I'm sure we will be hearing lots more about the new find. Stay tuned.