For the first time ever, astronomers have detected a galaxy located millions of light-years from Earth with almost no dark matter at all. Dark matter is called so as it can’t be seen and does not emit light or energy.

This is the reason that dark matter can never be detected directly. Notably, most of the galaxies are believed to be comprised of more dark matter than regular matter.

It is believed that halos of dark matter help galaxies from spinning apart as they rotate. Scientists have still not been able to decode the mystery surrounding dark matter. They only know dark matter does exist everywhere and has its own gravitational pull. In fact, dark matter is thought to make up 27 percent of all the mass and energy of the Universe. This is a certainly a big discovery for them.

The galaxy NGC 1052-DF2, or DF2 for short, reportedly has 400 times less dark matter than expected for an object of its size. It is located about 65 million light-years away in the constellation of Cetus. The newly discovered galaxy is about the volume and size of the Milky Way but has 200 times fewer stars.

“We didn’t expect that this could happen,” said Yale University astronomer Pieter van Dokkum who is also the lead author of the study.

He added that discovery of such a galaxy without dark matter was completely unexpected as the mysterious, invisible substance is the most dominant aspect of any galaxy. In fact, it is believed that galaxies start their lives as blobs of dark matter. Dokkum said that the discovery challenges the standard ideas of galaxy formation.

Scientists spotted NGC1052-DF2 using the Dragonfly Telephoto Array in New Mexico. The Dragonfly Telephoto Array was custom-built to spot these types of galaxies.

The research was published online in the journal Nature.