Abell 520 is a gigantic merger of galaxy clusters located 2.4 billion light-years away. Dark matter is not visible, although its presence and distribution is found indirectly through its effects. Dark matter can act like a magnifying glass, bending and distorting light from galaxies and clusters behind it. Astronomers can use this effect, called gravitational lensing, to infer the presence of dark matter in massive galaxy clusters.
MORE: http://www.nasa.gov/home/hqnews/2012/mar/HQ_12-068_Hubble_Dark_Core.html
gaw
Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://friendsofthezeiss.org >
Electronic Mail - < gawalsh@planetarium.cc >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.
Twitter: < http://twitter.com/
Facebook: < http://www.facebook.com/pages/
Blog: < http://spacewatchtower.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
< http://www.planetarium.
* Adler Planetarium, Chicago:
< http://adlerplanetarium.
* Astronomer, Educator, Optician John A. Brashear:
< http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
< http://www.andrewcarnegie.
* Civil War Museum of Andrew Carnegie Free Library:
< http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
< http://inclinedplane.tripod.
* Public Transit:
< http://andrewcarnegie2.tripod.
No comments:
Post a Comment