The Mars rover Opportunity appears to have landed in a small crater, the US space agency says after looking at the pictures the vehicle has returned.
The images suggest the shallow crater is about 20 metres (66 feet) across.
Nasa researchers believe the location is ideal to study the local rocks and soil and allows them to see what is beneath the surface without digging.
"We have scored a 300-million-mile interplanetary hole in one," enthused lead scientist Dr Steve Squyres.
Opportunity touched down on the Martian surface at 0505 GMT on Sunday, at Meridiani Planum, which is near the Martian equator and is thought to be rich in a mineral called grey haematite.
The mineral is usually formed on Earth in the presence of water.
The rover is a twin of the Spirit vehicle which landed on the planet on 4 January. It has already sent back stunning images of the Red Planet - although it is now experiencing software problems and is currently returning no science data.
The first pictures of Opportunity's landing site show an environment dominated by smooth, dark soil - but there is also a rocky outcrop nearby.
The landscape is quite unlike the boulder-strewn site of Spirit's Gusev Crater location 10,600 kilometres (6,600 miles) away on the other side of Mars.
Scientists had hoped for a specific landing site where they could examine both the surface layer that is rich in haematite and an underlying geological feature of light-coloured layered rock.
The outcrop is a native of Meridiani Planum
The small crater appears to have exposures of both, with soil that could be the haematite unit and an exposed outcropping of the lighter rock layer.
"If it got any better, I couldn't stand it," said Dr Doug Ming, a rover science team member.
With the instruments on the rover and just the rocks and soil within the small crater, Opportunity should allow scientists to determine which of several theories about the region's past environment was correct, he said.
Those theories include that the haematite may have formed in a long-lasting lake or in a volcanic environment.
Images taken on the descent indicate there is another crater about 150 metres (about 500 feet) across within about a kilometre of the landing site.
"Opportunity has touched down in a bizarre, alien landscape," Dr Squyres said. The rock outcrop was scientifically invaluable because, he explained, unlike stones that can come from elsewhere, the large slabs had to be linked to their location.
"It's their neighbourhood," he said.
Dr Squyre's science team is intrigued by the soil texture that looks pebbly, but, where touched by the lander's airbags, seems to have the consistency of talcum powder.
The Cornell University researcher said the fine soil could be the haematite-bearing material they went for.
"We drive off the lander, we look at the soil and we investigate this haematite mystery," he said as he outlined the planned investigation of the area.
"We go to the outcrop and we explore it in some detail, because it's right there in front of us, ready and ripe for the picking.
"We look at that carefully and we understand its geologic unit then we climb out of the crater, take a look around, and then we head for the big one... and it's going to be a wonderful adventure."
But Nasa must spend the next week or so unpacking and testing its six-wheeled vehicle.
Agency engineers also have to work to correct the problems which have halted the science mission of the Spirit rover.
The buggy is standing in front of a boulder in Gusev Crater unable to load its flight software properly.
Descent images have helped determine the local landscape
But engineers think they are getting on top of the problems.
"I think we have a patient that is well on its way to recovery," said Mars Exploration Rover project manager Pete Theisinger.
"You can't take anything for granted here, so once again don't expect us to be driving for a couple of weeks, maybe three."