Images taken by Europe's Mars Express spacecraft show a crater on the Red Planet that looks like a "happy face".
Crater Galle contains parallel gullies on its southern rim, a possible sign of liquid water running on Mars' surface.
Its interior has also been shaped by the action of wind and shows signs of "dust devil" tracks, which have removed the bright surface coating of dust.
A US space agency (Nasa) orbiter has also sent back its first colour image after arriving at Mars on 11 March.
The "face" in the European images was first pointed out in photos taken during Nasa's Viking Orbiter 1 mission.
The 230km- (143 mile-) wide impact crater contains a large stack of layered sediments which forms an outcrop in the southern part of the crater.
The US space agency's (Nasa) Mars Reconnaissance Orbiter (MRO) had already returned black and white images from its high-resolution cameras.
Mission scientists have now released a colour image of the eastern Bosporos Planum region.
This is not natural colour as seen by our eyes, but infrared colour (the infrared has longer wavelengths than visible light). The image has also been processed to enhance subtle colour variations.
The southern half of the scene is brighter and bluer than the northern half, perhaps due to early-morning fog in the atmosphere.
MRO's cameras will take the most detailed images ever of the Red Planet. Once the orbiter has descended to its lower mapping orbit, the cameras will be able to pick out objects just under 1m (3ft) across.