Researchers have found evidence of a massive explosion in the center of our galaxy that happened about 3.5 million years ago. On a cosmic timescale, that is very recently. The blast was so massive that its impact was felt 200,000 light-years away.
According to scientists, a massive expanding beam of energy originated close to the supermassive black home in the center of the Milky Way and sent a cone-shaped burst of radiation through both poles of the galaxy, out into deep space. The phenomenon is known as the Seyfert Flare and created a pair of enormous ionization cones that cut through the galaxy. The cones started with a relatively small diameter close to the black hole and expanded massively as it exited the galaxy.
Scientists say that the flare was so powerful that it impacted the Magellanic Stream. The Magellanic Stream is a long trail of gas extending from nearby dwarf galaxies called the Large and Small Magellanic Clouds. The Magellanic Stream is an average of 200,000 light-years from the Milky Way.
One scientist on the study, Professor Bland-Hawthorn, noted that the flare would have been like darkness and then someone switching on a lighthouse beacon for a brief period. While 3.5 million years is a distant time for humans, on Earth, when the flare occurred, the extinction of the dinosaurs was already 63 million years in the past.
The blast lasted for about 300,000 years, which is a very short period in galactic terms. The team says that before this study, scientists thought of our galaxy as an inactive galaxy with a not so bright center. This recent flare opens the possibility of a complete reinterpretation of its evolution and nature.