And they reveal what a strange place it must be.

The pole itself is covered in a layer of ice of unknown thickness.

Around it is a frozen desert with ridges of ice and dust laid down in layers over millions of years.

Channels, clearly seen in the image, have been eroded in the dust and morning frost clings to the slopes in shadow. Much of the ground seen in the image is frosty.

Some bluish-white wispy clouds are visible casting long dark shadows.

Sink without trace

When the surveyor takes more pictures of Mars's north pole in about six months, summer will have arrived. The frost will have gone and the region will look much darker.

But for now the surveyor has stopped taking pictures of Mars so that it can continue adjusting its orbit.

It is using the thin upper atmosphere of the red planet to "aerobrake" and change its orbit to a circular one that passes over both poles. This will enable all of Mars to be examined.

In the next few months two more Mars missions are to be launched.

In December the Mars Climate Orbiter will blast off followed in January 1999 by the Mars Polar Lander, which will land on the planet.