Ten billion years ago, another galaxy collided in the Milky Way.
But so far, astronomers have had to find the massive “fossil galaxy” that is still among us, according to a report in The Independent.
Researchers from the Apache Point Observatory (APOGEE) Galactic Evolution Experiment Project announced the discovery on Friday, the Independent reported.
They called the fossil galaxy Hercules and said its stars were found in the “halo” of the Milky Way, the cloud of stars furthest from the brighter center of our galaxy.
“It’s really small in a cosmological context – only 100 million stars,” Dr. Ricardo Chiavon said of the remains of Hercules.
Dr. Chiavon and his team could distinguish the stars of the Milky Way and Hercules because of their different chemical composition and speed.
“APOGEE allows us to break through this dust and see deeper into the heart of the Milky Way than ever before,” said Dr. Chiavon.
Based on scientific data, researchers have concluded that the collision of the two galaxies “must have been a major event in the history of our galaxy,” Shiavon said.
The researchers also said the incident made the Milky Way unusual because other “spiral galaxies had a much calmer early life.”
As our space home, the Milky Way is already special to us, but this ancient galaxy buried inside makes it even more special, ”said Dr. Chiavon.