Astronomy Picture of the Day 1-09-03

NASA ^ | 1-09-03 | Robert Nemiroff and Jerry Bonnell

[petuniasevan]

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2003 January 8

Abell 1689 Warps Space
Credit: N. Benitez (JHU), T. Broadhurst (Hebrew Univ.), H. Ford (JHU), M. Clampin(STScI),
G. Hartig (STScI), G. Illingworth (UCO/Lick), ACS Science Team, ESA, NASA

Explanation: Two billion light-years away, galaxy cluster Abell 1689 is one of the most massive objects in the Universe. In this view from the Hubble Space Telescope's Advanced Camera for Surveys, Abell 1689 is seen to warp space as predicted by Einstein's theory of gravity -- bending light from individual galaxies which lie behind the cluster to produce multiple, curved images. The power of this enormous gravitational lens depends on its mass, but the visible matter, in the form of the cluster's yellowish galaxies, only accounts for about one percent of the mass needed to make the observed bluish arcing images of background galaxies. In fact, most of the gravitational mass required to warp space enough explain this cosmic scale lensing is in the form of still mysterious dark matter. As the dominant source of the cluster's gravity, the dark matter's unseen presence is mapped out by the lensed arcs and distorted background galaxy images.

[petuniasevan]

Amazing - only 1% of the matter causing the lensing distortion is even VISIBLE. Dark matter is not merely "stuff we can't see", but seems to be comprised of particles we don't yet recognize or detect. Yet it comprises most of the structure of the Universe.

Lensing at Abell 2218

Spiral galaxy lensing a quasar into 4 images. The galaxy is NOT near the quasar.

Cosmic mirages!

[petuniasevan]

[GodBlessRonaldReagan]

Mind-boggling to think each of those small images is a galaxy...great pic!

[firewalk]

thanks for the ping (-:

[new cruelty]

Overwhelming. Thanks for including me in the list.

[xJones]

Dark matter is not merely "stuff we can't see", but seems to be comprised of particles we don't yet recognize or detect. Yet it comprises most of the structure of the Universe.

How Einstein would have loved seeing this.

[MeekOneGOP]

Cosmic bump...

[RightWhale]

seen to warp space

Gravitational lenses are interesting and their existence a fairly recent addition to our knowledge; but, over on the other thread the National Radio observatory has used the phenomenon to measure the speed of gravity. Catch that?

[Soaring Feather]

Fantastic

[Anti-Bubba182]

DONATE TODAY!!!. SUPPORT FREE REPUBLIC

Donate Here By Secure Server

Or mail checks to
FreeRepublic , LLC
PO BOX 9771
FRESNO, CA 93794

or you can use

PayPal at Jimrob@psnw.com
STOP BY AND BUMP THE FUNDRAISER THREAD