China: A lunar orbiter is being prepared for launch in 2007 or 2008, followed by lunar-landing probes and, after 2017, landings by astronauts.

Europe: A probe, Smart-1, is circling the moon. The European Space Agency hopes to send landing probes to our sister orb in later years.

India: Chandrayaan-1, a robotic spaceship, is scheduled for launch in September 2007. Its goals include orbiting the moon to map its minerals and seek frozen-water deposits that might be consumed by future astronauts.

Japan: A robotic probe, SELENE (Selenological and Engineering Explorer) is slated to visit the moon later this decade. However, its timing is uncertain because of repeated launch delays and the Japanese space program's well-publicized technical problems of the past decade.

United States: NASA plans to launch its Lunar Reconnaissance Orbiter in late 2008 as a prelude to President Bush's goal to send American astronauts back to the moon, perhaps as soon as the second half of the next decade.

Among many reasons, Foing said, is that the moon might contain relics of the origins of Earthly life. Billions of years ago, asteroid impacts on Earth could have splattered terrestrial crust onto the moon. That means that primeval fossils of Earth's earliest creatures might be scattered across the lunar terrain. For this reason, Foing jokingly calls the moon "Earth's attic."

Pieters of Brown University doesn't know what kinds of benefits — say, new types of energy sources or valuable elements that might be extracted more easily and cost-effectively than on Earth — might come from the moon. But she's confident benefits are there, only 240,000 miles from Earth.