In CNN’s report on the discovery that Mars once had liquid water – and thus may have once been hospitable to life – it mentions that the Spirit and Opportunity missions cost about $820 million. The IMDB estimates the budget for Spider-Man 2 at $200 million.
In other words, each mission cost two big-budget summer movies.
Maybe we should get Hollywood to finance space exploration. It might help placate the “We’re wasting too much money in space!” crowd without abandoning the pursuit of knowledge.