Its geology is laid out bare for all to see in this new image

Apr 14, 2014 09:54 GMT  ·  By

NASA astronauts with the Expedition 29 crew aboard the International Space Station (ISS) have recently captured this new image of the Grand Canyon, a geological feature in the United States that began forming some 17 million years ago. The formation is now the largest of its type on Earth and one of the largest on all planets in the solar system.

The canyon is around 446 kilometers (277 miles) long, some 29 kilometers (18 miles) across at its widest point, and reaches a depth of up to 1,800 meters (6,000 feet) at some points. The Colorado River – the main natural force that carved it – has thus exposed more than two billion years of Earth's geological history, by digging deep into the Colorado Plateau.

This high-obliquity image reveals the depth and spread of the Grand Canyon, which is even today one of the most important tourist attractions on the North American continent. Its characteristic steep walls are clearly visible in this image, which was collected from an altitude of around 420 kilometers (260 miles) above Earth's surface.

The Colorado River can be seen here as a dark and narrow strip at the bottom of the canyon. Geologists say that the river lies around 715 meters (2,345 feet) below the rims of this geological feature for most of its course. An active erosion process is still going on today, meaning that the canyon is getting deeper and deeper with each passing day.