This is a composite image of the south pole of Mars. Kinda looks like candy. Probably doesn’t taste like candy.
Where you see white is a vast region of permanently frozen water ice, many kilometers thick, covered in winter by a few-meter-deep veneer of frozen carbon dioxide, commonly called dry ice. In the Martian summer, the temperature at the pole gets high enough to turn the dry ice into a gas, but the water ice stays frozen. Not all the dry ice disappears, but even in winter the underlying water ice cap is far thicker than the dry ice above it.