Q. The Messenger Satellite launched by NASA is to study:
Answer: Mercury
Notes: MESSENGER (an acronym of Mercury Surface, Space Environment, Geochemistry and Ranging) is a robotic NASA spacecraft orbiting the planet Mercury, the first spacecraft ever to do so. The 485-kilogram spacecraft was launched aboard a Delta II rocket in August 2004 to study Mercury’s chemical composition, geology, and magnetic field. It became the second mission after 1975’s Mariner 10 to reach Mercury successfully when it made a flyby in January 2008, followed by a second flyby in October 2008, and a third flyby in September 2009.