Previous theories of the Large Magellanic Cloud and Small Magellanic Cloud (LMC and SMC, respectively) proposed that the two dwarf galaxies were doomed to spiral around the Milky Way until finally merging with their parent galaxy. Then evidence from the Hubble Space Telescope suggested the opposite, that they were merely passers-by. Now, the tables have turned one more time. Recent observations from the Australia Telescope National Facility have shown that the Magellanic clouds are leaking hydrogen into the Milky Way, in a sweeping arc of gas called HVC306-2+230.
This sweeping arc of gas, if it were visible to the naked eye, would pierce the Milky Way in the Southern Cross. Of course, this changes our perception of the Magellanic clouds. This new-found evidence points more to the fact that the clouds have been long partners with the Milky Way, in their spiraling path into the Milky Way. Astronomers aren't abandoning old theories, however, as more data are needed to really put this mystery to bed.
Original press release ->