The second satellite to reach Mercury is NASA's MESSENGER. It stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging. It was launched on August 3, 2004. It made a fly-by of Earth in August 2005. It made another fly-by of Venus in October 2006. It made its first fly-by of Mercury happened on January 14, 2008, a second on October 6, 2008, and a third on September 29, 2009. Most of the hemisphere not mapped by "Mariner 10" was mapped during these fly-bys. The satellite entered an elliptical orbit around the planet on March 18, 2011. The first image of Mercury orbiting the Sun was gotten on March 29, 2011.