Robby
21st February 2008, 04:42 AM
http://antwrp.gsfc.nasa.gov/apod/image/0802/horsehead_bertol.jpg (http://antwrp.gsfc.nasa.gov/apod/image/0802/horsehead_bertol_big.jpg)
Orion's Horsehead Nebula
Credit & Copyright: Victor Bertol ( victorbertol at yahoo dot es)
Explanation: The Horsehead Nebula (http://en.wikipedia.org/wiki/Horsehead_nebula) is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula (http://antwrp.gsfc.nasa.gov/apod/emission_nebulae.html) seen just below and left of center in the this photograph (http://www.pbase.com/yakete73/image/92789100). The brightest star on the left is located in the belt of the familiar constellation Orion (http://www.astro.wisc.edu/~dolan/constellations/ constellations/Orion.html). The horse-head (http://antwrp.gsfc.nasa.gov/apod/ap070527.html) feature is dark because it is really an opaque dust (http://antwrp.gsfc.nasa.gov/apod/ap030706.html) cloud that lies in front of the bright red emission nebula (http://fusedweb.pppl.gov/CPEP/Chart_Pages/5.Plasmas/ Nebula/Emission.html). Like clouds in Earth's atmosphere, this cosmic cloud has assumed a recognizable shape (http://www.brucevanpatter.com/cloudshapes.html) by chance. After many thousands of years, the internal motions of the cloud will alter its appearance. The emission nebula (http://antwrp.gsfc.nasa.gov/apod/ap061015.html)'s red color is caused by electrons (http://www.aip.org/history/electron/) recombining with protons (http://www.neutron.anl.gov/hyper-physics/proton.html) to form hydrogen (http://periodic.lanl.gov/elements/1.html) atoms. Also visible in the picture are blue reflection nebulae (http://antwrp.gsfc.nasa.gov/apod/reflection_nebulae.html) that preferentially reflect the blue light (http://antwrp.gsfc.nasa.gov/apod/ap030121.html) from nearby stars.
(Via NASA (http://antwrp.gsfc.nasa.gov/apod/ap080221.html))
Orion's Horsehead Nebula
Credit & Copyright: Victor Bertol ( victorbertol at yahoo dot es)
Explanation: The Horsehead Nebula (http://en.wikipedia.org/wiki/Horsehead_nebula) is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula (http://antwrp.gsfc.nasa.gov/apod/emission_nebulae.html) seen just below and left of center in the this photograph (http://www.pbase.com/yakete73/image/92789100). The brightest star on the left is located in the belt of the familiar constellation Orion (http://www.astro.wisc.edu/~dolan/constellations/ constellations/Orion.html). The horse-head (http://antwrp.gsfc.nasa.gov/apod/ap070527.html) feature is dark because it is really an opaque dust (http://antwrp.gsfc.nasa.gov/apod/ap030706.html) cloud that lies in front of the bright red emission nebula (http://fusedweb.pppl.gov/CPEP/Chart_Pages/5.Plasmas/ Nebula/Emission.html). Like clouds in Earth's atmosphere, this cosmic cloud has assumed a recognizable shape (http://www.brucevanpatter.com/cloudshapes.html) by chance. After many thousands of years, the internal motions of the cloud will alter its appearance. The emission nebula (http://antwrp.gsfc.nasa.gov/apod/ap061015.html)'s red color is caused by electrons (http://www.aip.org/history/electron/) recombining with protons (http://www.neutron.anl.gov/hyper-physics/proton.html) to form hydrogen (http://periodic.lanl.gov/elements/1.html) atoms. Also visible in the picture are blue reflection nebulae (http://antwrp.gsfc.nasa.gov/apod/reflection_nebulae.html) that preferentially reflect the blue light (http://antwrp.gsfc.nasa.gov/apod/ap030121.html) from nearby stars.
(Via NASA (http://antwrp.gsfc.nasa.gov/apod/ap080221.html))