Mars without its makeup can look a little blue. Heres why.

On a summer morning on Mars , NASA 's Curiosity rover woke in its usual crater, opened its shutter, and snapped a sprawling view carpeted in blues and grays.

The panorama subverts the usual perception of the Red Planet, a reputation that dates to ancient civilizations.

Romans called it Mars, the god of war, because its color reminded them of blood.

Egyptians called it Her Desher — "the red one." Even people today associate Mars with rust: dry, desolate, and caked with iron minerals that oxidize red.

Curiosity captured this scene on Aug.

11, around 8:30 a.m. local time with its Mastcam instrument.

A pale custard sky hangs above slate-colored terrain.

What makes the image strange is what the U.S. space agency didn't do.

The team almost always adjusts the colors in Mars photos before releasing them.

This time, it skipped that step and kept the dim morning light as the camera recorded it.

In a news release, NASA called it " an artistic choice ." Which brings up a surprisingly complex question.

No human has ever stood on Mars, so what would the planet actually look like to someone who did? The answer depends on several factors: the weaker sunlight to its farther distance, the dust suspended in the air, the minerals on the ground, the camera's sensor, the editing software, and, not to be underestimated, the eye of the beholder.

SEE ALSO: Astronomers spot something positively enormous behind the Milky Way When mission teams tweak the photos, scientists say the goal is to make the rocks look as they would in sunlight on Earth.

Martian dust tints everything the sun touches, so removing its influence shows the rocks' intrinsic colors.