At the center of our galaxy is a black hole with the mass of 4 million suns called Sagittarius A*. Around it is a complicated structure of dust and gas, and after 12 years of peering into it, astronomers have discovered several objects they weren’t expecting to find. Objects that have some unusual characteristics.
They’re called G objects. They orbit around Sagittarius A* and have a dusty appearance. The first one, imaginatively named G1, was found in 2004. G2 was spotted in 2012, and G3, G4, and G5 were just announced in the summer of 2018. There’s no G6 yet, but I expect when they find it it’ll move with a Far East Movement. Nobody under 20 gets that reference.
They look like dust clouds, and astronomers thought they might just be dust clouds too. Back when only G1 and G2 had been spotted they had a very similar orbit, so one hypothesis was they were once part of the same dust cloud that had been stretched out until it formed smaller clumps like beads on a string, a process that has been observed elsewhere in the universe. But when these fast moving objects passed close to Sagittarius A*, they didn’t behave how dust clouds should.