ISS "Firestation" to Explore the Tops of Thunderstorms   
       
   Sept. 10, 2013:  We all know what comes out of the bottom of thunderstorms:   
   bolts of lightning. Jagged columns of light plunge Earthward, heating the air   
   to 50,000 degrees F, about five times hotter than the surface of the sun.   
   Claps of thunder announce this process somewhere on Earth as often as 50 times   
   a second.   
       
   Have you ever wondered, though, what comes out of the top?   
       
   http://www.youtube.com/watch?v=vNmUfcc_zBk   
       
   A new ScienceCast video explores the strange things coming from the tops of   
   thunderstorms. Play it   
       
   In recent decades researchers have discovered some strange things happening in   
   the cloud tops.  High above ordinary lightning, exotic forms known as red   
   sprites and blue elves shoot toward the heavens, cold cousins to the fiery   
   bolts below. In some places jets of antimatter fly upwards, triggering the   
   detectors on NASA's orbiting high-energy observatories.  And as often as 500   
   times a day, Earth briefly mimics a supernova, producing a powerful blast of   
   gamma-rays known as a Terrestrial Gamma-ray Flash or TGF.   
       
   No know knows exactly how these phenomena are related either to each other or   
   to the lightning down below.   
       
   Auroras Underfoot (signup)A new experiment called "Firestation" onboard the   
   ISS aims to find out.  Firestation is a package of sensors designed to explore   
   the links between TGFs, ordinary lightning, and sprites.   
       
   "The space station's orbit will carry Firestation directly above thousands of   
   active thunderstorms during the one-year lifetime of the experiment," says   
   principal investigator Doug Rowland at NASA's Goddard Space Flight Center.    
   "The ISS is perfect for this kind of research."   
       
   Unlike previous experiments in upper atmospheric lightning, Firestation has   
   the unique ability to observe thunderstorms at multiple wavelengths   
   simultaneously.  It can record the radio static from lightning, measure its   
   optical glow (including the red and blue light of sprites and elves), and   
   detect the gamma-rays and electrons associated with TGFs and antimatter events.   
       
   Firestation has radio, optical, and gamma-ray sensors. MoreRowland expects   
   Firestation to observe up to 50 lightning strokes per day, at least one TGF   
   every few hours, and a large TGF every couple of days. Such a firehose of   
   multi-wavelength data will allow researchers to sort out cause-and-effect   
   connections impossible to see in previous studies.   
       
   "There are several different types of lightning," Rowland says.  "At the   
   moment, we don't even know which type produces a gamma-ray flash." Firestation   
   could solve that decades-old mystery in its first few weeks of operation.   
       
   The thing that intrigues Rowland most about TGFs is their surprising   
   energetics.   
       
   "Gamma-rays are thought to come from the most violent events in the cosmos   
   like stars colliding or exploding," he points out. "What a surprise to find   
   them shooting out of the cold upper atmosphere of our own planet."   
       
   Something up there is accelerating low-energy particles of air to nearly the   
   speed of light, producing gamma-radiation and, sometimes, a cascade of   
   antimatter.  Rowland wants to find out what that strange, unknown "something"   
   is.  Firestation is poised to crack the mystery.   
       
   The experiment was delivered to the ISS on August 3, 2013, by the Japanese   
   robotic cargo vessel "Kounotori-4." It has since been installed on the   
   station's exterior by the station's robotic arm.  All of the sensors were   
   checked out at the end of August and full-time science operations are slated   
   to begin in early September 2013.   
       
   Credits:   
       
   Author: Dr. Tony Phillips |Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
   Related Links:   
       
   Dark Lightning  -- ScienceCast video   
       
   Are TGFs Hazardous to Air Travelers? -- Science@NASA   
       
   Firefly Mission to Study Terrestrial Gammaray Flashes -- Science@NASA   
       
   Thunderstorms Make Antimatter -- Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.94   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)