14 DAY TRIAL // Hubble Space Telescope has just discovered a gigantic, ghostly ring of dark matter at a distance of 5 billion light-years from Earth. So far, it's the most compelling evidence of the existence of the elusive dark matter.
Scientists have theorized on the existence of dark matter for some time, and they think it's a cosmic phenomenon that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter.
Far more dark matter is supposed to exist in the Universe, around 23 percent on its entire mass, acting like a gravitational "glue" that keeps galaxies like our Milky Way from falling apart.
The latest contribution to science from the aging Hubble telescope, about to be decommissioned in a few years, is the discovery of the mysterious ring of dark matter in a cluster of galaxies known as cluster ZwCl0024+1652.
At a first glance, the then-unknown ring looked like a ripple in a pond over the twinkling galactic cluster, and was even supposed to be a glitch in the telescope's systems, until astronomers announced at a NASA press conference today that the pictures were real.
"I was annoyed when I saw the ring because I thought it was an artifact," said Myungkook James Jee of Johns Hopkins University. "It took more than a year to convince myself that the ring was real. I've looked at a number of clusters and I haven't seen anything like this," Jee said.
Due to the fact that there's so much dark matter in the ring, it bends the light around it to create the ripple effect--dark matter's calling card.
The dark matter ring is 2.3-million light-years wide and has formed after two huge clusters of galaxies slammed together in a head-on collision roughly 1 to 2 billion years ago, puffing the mysterious matter outward. "The background galaxies behind the ring show coherent changes in their shapes due to the presence of the dense ring. It's like looking at the pebbles on the bottom of a pond with ripples on the surface."
This is the first serious evidence of the existence of dark matter ever recorded, being the first collection of dark matter that differs greatly from the distribution of ordinary matter.