By Dean Murray
A NASA image of the snow-dusted Grand Canyon has created a striking optical illusion, making the vast chasm—more than a mile deep—resemble a mountain range.
Captured on January 26 by an astronaut on the International Space Station, the photograph shows winter snow lingering on the higher South and North rims after recent flurries.
The deceptive effect stems from a phenomenon known as relief inversion, where viewers unconsciously expect light from the top of an image, but here the Sun shone from the south, at the bottom.
NASA Earth Observatory said: “If these photos make the iconic feature of the American West look more like a mountain range than a vast chasm, the effect is likely due to a visual illusion called relief inversion.
“Though the shadows on the canyon walls may be visually deceiving, the presence of snow helps to signal that the flat areas sit at higher elevations.”
