Scientists are divided about the use of the Moon as a base to develop ways to travel to Mars, according to reports given to the US government. Some have said the possibility of water-ice existing at the lunar poles would allow a moonbase to use the ice as rocket fuel for a Mars mission. Others contend that it would be too difficult to extract. And there is disagreement about whether the moon is a good alternative to space as a base for advanced telescopes. In January, President Bush redirected the US space effort sending astronauts back to the Moon and...