It’s a little like that Facebook dress controversy that wouldn’t go away, but on a much more significant level.

New photos from NASA’s Curiosity rover are posing a new question: What color is Mars -- really?

You probably know it as the Red Planet. But the new pictures also show it’s a little blue — or is it a little grey?

As Anaridis Rodriguez of explains in the , the planet’s true color depends on the eye of the camera.

Mars looks red because it’s covered with iron oxide, which is rust dust.

But Curiosity’s new photos show it’s a bit different just under the surface. The rover drilled into the soil and found Mars is actually more blue-ish grey.

NASA says that’s because the deeper soil is less oxidized, or less rusty, than the surface layer.

MORE ON WEATHER.COM: Hubble's Best Images

April 24 marks the 25th anniversary of the Hubble Telescope. To celebrate, NASA and the European Space Agency, which jointly run the telecope, released this image of the star cluster Westerlund 2. (NASA/ESA/Hubble Heritage Team/A. Nota/Westerlund 2 Science Team)