The decision on where to land Curiosity, the super-sized roving science laboratory bound for Mars later this year, isn’t expected for at least another two weeks, NASA officials said on Monday.

On Friday, John Grotzinger, project scientist for the $2.5 billion Curiosity, presented an assessment of four potential landing sites to NASA Associate Administrator Ed Weiler and a council of top NASA officials in the science mission directorate. Last week, Nature reported that a secret vote held by Grotzinger and his science team last month had put Gale Crater at the top of the list, followed closely behind by Eberswalde Crater. The Gale site is expected to contain ancient lakebeds, while Eberswalde may hold a relic river delta.

NASA headquarters was prepared to roll out an official announcement as early as today, had the council and Weiler come to an easy decision. But Weiler, who will make the final call, has instructed the council to study the information that was presented to them for the next two weeks.