x00 writes, According to a BBC News article, Russell T Davies has said that budget constraints keep Doctor Who on Earth. He also stated “The programmes that do show alien planets are not prime-time programmes”. Personally I happen to disagree with him. And the episodes “The Impossible Planet” and “Satan’s Pit” were possibly the best episodes of the series. Oh, and as they mentioned in Doctor Who Confidential, the Pit was actually filmed in a quarry.