Hubble Provides New Evidence For Dark Matter Around Small Galaxies

[NOW tense]

ScienceDaily (Mar. 13, 2009) — NASA’s Hubble Space Telescope has uncovered a strong new line of evidence that galaxies are embedded in halos of dark matter.
Peering into the tumultuous heart of the nearby Perseus galaxy cluster, Hubble discovered a large population of small galaxies that have remained intact while larger galaxies around them are being ripped apart by the gravitational pull of neighbouring galaxies. The results appear in the March 1st edition of the journal Monthly Notices of the Royal Astronomical Society.

Dark matter is an invisible form of matter that accounts for most of the Universe’s mass. Astronomers have deduced the existence of dark matter by observing its gravitational influence on normal matter which consists of stars, gas, and dust.

The Hubble images provide further evidence that the undisturbed galaxies are enshrouded by a “cushion” of dark matter, which protects them from their rough-and-tumble neighbourhood.

http://www.sciencedaily.com/releases/2009/03/090312093947.htm