The MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging)
mission is a scientific investigation of the planet Mercury.
Understanding Mercury and the forces that have shaped it is
fundamental to understanding the evolution of the terrestrial planets. MESSENGER will orbit Mercury for one Earth year following two
flybys of that planet. The orbital phase will use the flyby data as a guide to perform a focused scientific investigation
designed to answer key questions about Mercury's characteristics and environment.
MISSION OBJECTIVES
MESSENGER launched on August 3, 2004, aboard a Boeing Delta II rocket from Cape Canaveral Air Force Station, FL. It returned to fly past Earth for a gravity assist a year after liftoff. The spacecraft has now completed two flybys of Venus and is on its way to Mercury. It will fly by Mercury three times before starting a yearlong orbit of the innermost planet in March 2011.
MESSENGER's science goals are to provide the first images of the entire planet and collect detailed information on the composition and structure of Mercury's crust, its geologic history, the nature of its thin atmosphere and active magnetosphere, and the makeup of its core and polar materials.
(Click image for full size view)
Visited previously by only one spacecraft, Mariner 10, Mercury's density is the highest of any planet. Its exotic atmosphere is the thinnest among all the terrestrial planets. It is the only terrestrial planet besides Earth to possess a global magnetic field. Temperatures on this planet of fire and ice vary from nearly the highest in the solar system, at the equator, to among the coldest, in the permanently shadowed poles where ice deposits seem to lurk.
The MESSENGER mission's science objectives will be pursued using an optimized set of seven miniaturized instruments plus the spacecraft communication system: What is the origin of Mercury's high density? What are the composition and structure of its crust? What is Mercury's tectonic history, and is its surface shaped by volcanism? What is the nature and origin of Mercury's magnetic field? What are the characteristics of the thin atmosphere and miniature magnetosphere? What is the nature of the mysterious polar caps? MISSION MANAGEMENT The MESSENGER mission is managed for NASA by the Johns Hopkins University Applied Physics Laboratory in Laurel, MD. The Principal Investigator is Dr.
Sean C. Solomon of the Carnegie Institution of Washington.
For more complete information on the mission, visit the MESSENGER home page.
What is the origin of Mercury's high density?
