In what has become a regular yearly occurrence, the Spirit rover is looking for a comfortable warm spot to spend the Martian winter. Spirit is heading toward a north-facing slope, where it is hoped the rover can eke out enough sunlight to keep its systems ticking over until Summer. A number of such slopes were considered and rejected, and Spirit is now heading toward a particular promising one at the northern end of Home Plate, an intriguing geologic feature that had taken up several months research time for the rover. The 60-meter drive is worth the risk, as the slope provides a 25-degree incline that will maximise the available sunlight. Spirit can't afford to be cavalier about where it hunkers down for winter. After a long dust storm, the solar panels are covered in dust, so every extra bit of power will be crucial to survival this year. Unlike the rover’s sister Opportunity, they cannot count on a lucky gust of wind to clean the cells. Opportunity is in a windy locale; the area that Spirit is traversing now is almost windless. It is hoped that Spirit can be bedded down by the 1st January 2008, but it may then have to stay under cover for eight months.