Alien Matter in the Solar System: A Galactic Mismatch   
       
   Feb. 10, 2012:  This just in:  The Solar System is different from the space   
   just outside it.   
       
   Researchers announced the finding at a press conference on Jan. 31, 2012. It's   
   based on data from NASA's IBEX spacecraft, which is able to sample material   
   flowing into the solar system from interstellar space.   
       
   "We've detected alien matter that came into our solar system from other parts   
   of the galaxy--and, chemically speaking, it's not exactly like what we find   
   here at home." says David McComas the principal investigator for IBEX at the   
   Southwest Research Institute in San Antonio, Texas.   
   [...]   
   Click to view a ScienceCast video about IBEX's measurements of "alien matter"   
   in the solar system   
       
   Our solar system is surrounded by the heliosphere, a magnetic bubble that   
   separates us from the rest of the Milky Way.  Outside the heliosphere lies the   
   realm of the stars or "interstellar space"; inside lies the sun and all the   
   planets.  The sun blows this vast magnetic bubble using the solar wind to   
   inflate the sun's own magnetic field.  It's a good thing: The heliosphere   
   helps protect us from cosmic rays that would otherwise penetrate the solar   
   system.   
       
   Launched in 2008, the IBEX spacecraft spins in Earth orbit scanning the entire   
   sky.  IBEX's special trick is detecting neutral atoms that slip through the   
   heliosphere's magnetic defenses.  Without actually exiting the solar system,   
   IBEX is able to sample the galaxy outside.   
       
   The first two years of counting these alien atoms have led to some interesting   
   conclusions:   
       
   "We've directly measured four separate types of atoms from interstellar space   
   and the composition just doesn't match up with what we see in the solar   
   system," says Eric Christian, mission scientist for IBEX at NASA's Goddard   
   Space Flight Center in Greenbelt, Md.   
       
   Among the four types of atoms detected-H, He, O and Ne-the last one, neon,   
   serves as a particularly useful reference. "Neon is a noble gas, so it doesn't   
   react with anything. And it's relatively abundant, so we can measure it with   
   good statistics," explains McComas.   
       
   Using data from IBEX, the researchers team compared the neon-to-oxygen ratio   
   inside vs. outside the heliosphere. In a series of six science papers   
   appearing in the Astrophysical Journal, they reported that for every 20 neon   
   atoms in the galactic wind, there are 74 oxygen atoms. In our own solar   
   system, however, for every 20 neon atoms there are 111 oxygen atoms.   
       
   That translates to more oxygen in any given slice of the solar system than in   
   local interstellar space.   
   [...]   
   An artist's concept of Voyager approaching the edge of the solar system.   
   [more] Where did the extra oxygen come from?   
       
   "There are at least two possibilities," says McComas. "Either the solar system   
   evolved in a separate, more oxygen-rich part of the galaxy than where we   
   currently reside or a great deal of critical, life-giving oxygen lies trapped   
   in interstellar dust grains or ices, unable to move freely throughout   
   space-and thus undetectable by IBEX."   
       
   Either way, this affects scientific models of how our solar system - and life   
   - formed.   
       
   "It's a real puzzle," he says.   
       
   While IBEX samples alien atoms from Earth orbit, NASA's Voyager spacecraft   
   have been traveling to the edge of the heliosphere for nearly 40 years-and   
   they could soon find themselves on the outside looking in.  Researchers expect   
   Voyager 1 to exit the solar system within the next few years. The new data   
   from IBEX suggest the Voyagers are heading for a new frontier, indeed.   
       
       
   Author:Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
   More Information   
   Giant Ribbon Discovered at the Edge of the Solar System -- Science@NASA   
       
   Mystery of the Giant Ribbon, Solved?  -- Science@NASA   
       
   A Big Surprise from tthe Edge of the Solar System -- Science@NASA   
       
   IBEX Home Page (NASA)   
       
   IBEX Mission Page (SWRI)   
       
   IBEX is the latest in NASA's series of low-cost, rapidly developed Small   
   Explorers space missions. Southwest Research Institute in San Antonio, Tx.,   
   leads and developed the mission with a team of national and international   
   partners. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the   
   Explorers Program for NASA's Science Mission Directorate in Washington.   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.75   
    * Origin: NCS BBS (1:3828/7)