The European Space Agency (ESA) has an x-ray observatory called XMM-Newton and a team of international astronomers to find part of the “missing” matter in the universe.

A number of years ago scientists predicted that half of the missing “normal” matter was simply made of atoms existing in low density gas between galaxies. No they mean really low density gas, density so low it is hard to detect. What they did was detect the warmest part of this interstitial space.

That’s “normal matter” and amazingly that is only about 5 percent of what makes up the universe. Pretty hard to imagine isn’t it? 95 percent of the universe is made up of stuff we can’t see, touch, or detect. It’s a combination of “dark matter (23%) and dark energy (72%). Strange stuff! Astroprof has done a few great posts on dark matter, here’s a like to the first one.

To read more about the discovery, which is a pretty significant find go here.

About the image (Credit: ESA/ XMM-Newton/ EPIC/ ESO (J. Dietrich)/ SRON (N. Werner)/ MPE (A. Finoguenov)):
Composite optical and X-ray image of galaxy clusters Abell 222 and Abell 223. The cluster pair is connected by a filament permeated by hot X-ray emitting gas.

The optical image was obtained by SuprimeCam at the Subaru telescope, the X-ray image showing the distribution of the diffuse hot gas (yellow to red) was obtained by XMM-Newton.

Incidentally the bright vertical lines on some of the stars is due to the pixel on the CCD chip becoming saturated, very common even if you don’t see it a lot in published images — it’s called blooming.