Moons are great space destinations because they contain material resources and generally have fairly small
gravity wells. However, moons orbit massive planets that require significant expenditure of fuel
to attain and leave orbit. However, moons remain attractive destinations because many of them have water
and other important resources.
Source: Wikipedia. Fair use for educational purposes.
Enceladus
Enceladus orbits Saturn.
“A computer graphic created with Cassini data of Saturn’s moon Enceladus illustrates the immense scale
of its south polar water plumes where data also indicate that relatively warm subsurface temperatures and
chemistry could support life."
Credit: NASA/JPL.” From Aviation Week & Space Technology, April 14, 2008.
Fair use for educational purposes.
Phobos
Phobos orbits Mars.
“The Martian moon Phobos, imaged in color for the first time by Mars Reconnaissance Orbiter (MRO), reveals
distinctive red material like that on the Martian surface. This could mean that Mars material, blasted into
space by meteorites, has collected on Phobos. It would be much easier for a sample return spacecraft to obtain
specimens there, rather than descending through, and back out of, the Martian atmosphere. A Russian spacecraft is
set for launch to Phobos in 2009 on a collection expedition. The HiRISE High-Resolution Imaging Science Camera on
MRO captured the image with 65-ft. resolution from a 4,200-mi. range. The illuminated face of the moon is just
13 mi. across. The large crater at right, named Stickney, is 5.6-mi. wide. The white material streaming from the
rim could be younger soil exposed by the meteorite impact that formed the crater.”
From Aviation Week & Space Technology, April 14, 2008. Fair use for educational purposes.
Titan
Titan orbits Saturn.
From “The Planetary Society Weblog,” by Emily Lakdawalla, http://www.planetary.org/blog/article/00000568/