Our Galaxy is huge with a radius of about 52,850 light years. It contains more than 25,000 crores stars. At the centre of our Milky Way galaxy there’s a big black hole with a radius of about 22 million kilometre. We call it Sagittarius A. Recently when astronomers were studying it, they found some weird bubble structures. Which was located very close to the black hole. Those bubbles are so big that they stretch for about 1,400 light years. And they are still expanding even more. But that’s not gonna last forever. Perhaps in hundreds of thousands of years they’ll run out of gas and will simply disappear. So what are those and how they formed? Well, researchers are still unsure about what caused those bubbles to form in the first place. But according to some scientists, the most probable possibility is, a few millions years ago, large stars got trapped into the black hole’s gravity and fell into the stomach of Sagittarius A and due to which large scale outbursts occurred. Which later converted into these large bubbles. There’s also another possibility, which is a cluster of stars formed at around the same time in that region. Which generated intense amount of energy. Those energies were blasted out to create those big bubbles. The researchers are still monitoring those bubbles and measuring how fast they’re expanding. Further study will help scientists understand if this is a one time event or it happens periodically as our galaxy evolve.