It looks like the Grand Canyon has some pretty stiff competition near both poles. In August, scientists announced they had found a Greenland canyon that dwarfs the famed one in Arizona. Now, researchers have repeated the feat—and then some—in the Antarctic. Phys.Org reports that a group of UK scientists used satellites and radar to study the Ellsworth Subglacial Highlands, an ancient mountain range buried under more than a mile of ice in West Antarctica. What they found: a mammoth valley almost 1.9 miles deep in places, now named the Ellsworth Trough. As Gizmodo points out, that's much deeper than the Grand Canyon, which is up to a mile deep.
The discovery of the canyon, which measures nearly 200 miles long and up to 15 miles wide, beneath so much ice was a find that lead author Dr. Neil Ross describes as "incredibly serendipitous." While the team had data from both ends of the trough from ice-penetrating radar, they didn't know what existed between, and had to rely on NASA satellite data to fill that hole—or, as it were, uncover one. Because, as Ross explains, even beneath all that ice, "the valley is so vast that it can be seen from space." He adds, "To me, this just goes to demonstrate how little we still know about the surface of our own planet." (Click for more on the canyon found in Greenland, which is grander than the Grand Canyon in one regard.)