Cold and Spellbinding: An Alignment of Planets in the Sunset Sky   
       
   Feb. 17, 2012:  Note to sky watchers: Put on your winter coats. What you're   
   about to read might make you feel an uncontrollable urge to dash outside.   
       
   The brightest planets in the solar system are lining up in the evening sky,   
   and you can see the formation-some of it at least-tonight.   
       
   Go out at sunset and look west.  Venus and Jupiter pop out of the twilight   
   even before the sky fades completely black.  The two brilliant planets   
   surrounded by evening blue is a beautiful sight.   
       
       
   Amateur astronomer G”ran Strand photographed Venus and Jupiter converging over   
   Fr”s”n, Sweden, on Feb.12, 2012. [video]   
   If you go out at the same time tomorrow, the view improves, because Venus and   
   Jupiter are converging.  In mid-February they are about 20 degrees apart.  By   
   the end of the month, the angle narrows to only 10 degrees-so close that you   
   can hide them together behind your outstretched palm.  Their combined beauty   
   grows each night as the distance between them shrinks.   
       
   A special night to look is Saturday, Feb. 25th, when the crescent Moon moves   
   in to form a slender heavenly triangle with Venus, Jupiter and the Moon as   
   vertices (sky map).  One night later, on Sunday, Feb. 26th, it happens again   
   (sky map). This arrangement will be visible all around the world, from city   
   and countryside alike.  The Moon, Venus and Jupiter are the brightest objects   
   in the night sky; together they can shine through urban lights, fog, and even   
   some clouds.   
       
   After hopping from Venus to Jupiter in late February, the Moon exits stage   
   left, but the show is far from over.   
       
   In March, Venus and Jupiter continue their relentless convergence until, on   
   March 12th and 13th, the duo lie only three degrees apart-a spectacular double   
   beacon in the sunset sky (sky map).  Now you'll be able to hide them together   
   behind a pair of outstretched fingertips.   
       
   There's something mesmerizing about stars and planets bunched together in this   
   way-and, no, you're not imagining things when it happens to you.  The   
   phenomenon is based on the anatomy of the human eye.   
       
       
   The fovea is responsible for our central, sharpest vision. [more] "Your eye is   
   a bit like a digital camera," explains optometrist Dr. Stuart Hiroyasu of   
   Bishop, California. "There's a lens in front to focus the light, and a   
   photo-array behind the lens to capture the image. The photo-array in your eye   
   is called the retina. It's made of rods and cones, the organic equivalent of   
   electronic pixels."   
       
   There's a tiny patch of tissue near the center of the retina where cones are   
   extra-densely packed. This is called "the fovea."   
       
   "Whatever you see with the fovea, you see in high-definition," Hiroyasu says.   
   The fovea is critical to reading, driving, watching television. The fovea has   
   the brain's attention.   
       
   The field of view of the fovea is only about five degrees wide. Most nights in   
   March, Venus and Jupiter will fit within that narrow cone.  And when they   
   do-presto!  It's spellbinding astronomy.   
       
   Standing outdoors, mesmerized by planets aligned in a late winter sunset, you   
   might just forget how cold you feel.  Bring a coat anyway..   
       
       
   Author:Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
   More Information   
   Sky maps:  Feb. 25, Feb. 26, March 12, March 13, 2012.   
   ScienceCast Video:An Alignment of Planets   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.75   
    * Origin: NCS BBS (1:3828/7)