NASA has released a series of stunning images captured by the Hubble Space Telescope. The set of images show eerie green clouds that are tens of thousands of light years away. According to Space.com, these eerie green clouds have been caused by extinct quasars whose powerful radiation levels caused the clouds to glow green.

In total, eight images that show these eerie green clouds have been captured by the Hubble Space telescope — all of which were recently released by NASA.

A statement accompanying the images, officials from the European Space Agency (ESA), which partners with NASA on the Hubble project state;

“In each of these eight images, a quasar beam has caused once-invisible filaments in deep space to glow through a process called photoionization. Oxygen, helium, nitrogen, sulfur and neon in the filaments absorb light from the quasar and slowly re-emit it over many thousands of years. Their unmistakable emerald hue is caused by ionized oxygen, which glows green.”

According to NASA, quasars are the brightest objects in the universe. They are usually found near bright galactic cores. In somewhat of an irony, the brightest objects in the universe are powered by the darkest objects in the universe. How? Quasars are usually the result of the effects of supermassive black holes. As the extremely powerful black hole pulls material towards it from its surrounding accretion disk, they are subjected to extreme temperatures and in the process result in a quasar. The heat results the materials to emit high energy particles out into space. The eerie green clouds photographed by Hubble Space Telescope are in all likelihood, clouds of gas that have been lit up by the radiation emitted by quasars.

Strangely, the quasars that caused these eerie green clouds to glow have long died out. This is because by the time the radiation from the quasars reached these clouds — located thousands of light years away from the center of their respective galaxies, the quasars were eventually gobbled up by the massive black hole that caused them.

As for the origins of the eerie green clouds themselves, according to ESA, it is likely that they were the result of violent galactic mergers of the past.

“Galactic mergers do not just alter the forms of the previously serene galaxies involved; they also trigger extreme cosmic phenomena. Such a merger could also have caused the birth of a quasar, by pouring material into the galaxies’ supermassive black holes,” ESA officials wrote in the statement.

These eerie green clouds were first discovered in 2007 by Dutch schoolteacher Hanny van Arkel. For the same reason these phenomenon is now named Hanny’s Voorwerp, Dutch for Hanny’s object.

As for the eight eerie green clouds that have been shown the NASA images, they have been confirmed to be found in the following galaxies:

2MASX J14302986+1339117, NGC 5972, 2MASX J15100402+0740370, UGC 7342, 2MASX J22014163+1151237, UGC 11185, Mrk 1498 and NGC 5252.

[Images Via NASA, ESA, and W. Keel (University of Alabama, Tuscaloosa) ]