See Mercury at Sunset   
       
   March 14, 2011: The timing couldn't be better. Just as NASA's MESSENGER probe   
   is about to enter orbit around Mercury, the innermost planet is popping out of   
   the twilight for its best apparition of 2011.   
       
   The show begins on March 14th. At the end of the day, go outside and look west   
   into the sunset. A bright star catches your eye-that's Jupiter. Just below it   
   lies Mercury, a little dimmer than the giant planet, but easy to find with   
   Jupiter's guidance.   
   [...]   
   Jupiter (left) and Mercury (right) photographed at sunset on March 13, 2011,   
   by Pete Lawrence of Selsey, UK. [larger image]   
       
   http://science.nasa.gov/media/medialibrary/2011/03/14/Pete-Lawrence1.jpg   
       
   Over the next few evenings, these two planets will "pass in the night,"   
   switching places so that Mercury is on top and Jupiter on the bottom. The   
   higher Mercury rises, the easier it is to see. By the evening of March 17th,   
   the innermost planet should be well above any distant trees or buildings-in   
   prime position for the big event.   
       
   March 17th is the night MESSENGER goes into orbit.   
       
   This has been a long time coming. MESSENGER was launched in Aug. 2004. Since   
   then it has looped around the sun 15 times, flown by three planets for   
   multiple gravity assists, and traveled some 5 billion miles. If getting there   
   sounds tricky, that's because it is. Mercury races around the sun faster than   
   100,000 mph, making it difficult to catch. Moreover, a spacecraft at Mercury   
   has to endure terrific heat and dangerous solar flares. In the whole history   
   of the space age, only two ships have dared fly by the planet-Mariner 10 in   
   1974-75 and MESSENGER itself in 2008-2009.   
   [...]   
   Mercury at sunset. Sky maps used with permission of Sky and Telescope.   
       
   Deep mysteries await MESSENGER when it arrives. There are hints that Mercury   
   has been shrinking-how is that possible? The poles of Mercury contain some   
   highly reflective material-could it be ice? What shapes Mercury's long   
   comet-like tail? What makes Mercury so dense? Are any of Mercury's volcanic   
   craters "fresh"? MESSENGER is bristling with instruments specifically designed   
   to answer these questions and many others.   
       
   A 15-minute engine burn on March 17th at 8:45 p.m. EDT will place MESSENGER   
   into orbit. At that historic moment, Mercury will be visible to the naked eye   
   across much of the USA. Go out and look. Only MESSENGER will have a better   
   view.   
       
       
   Author: Dr. Tony Phillips | Credit: Science@NASA   
       
   More Information   
   MESSENGER -- mission home page   
       
   Best Mercury of 2011 -- from Sky and Telescope   
       
   Mercury Orbit Insertion & Station Keeping   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.59   
    * Origin: NCS BBS (1:3828/7)