Huge Hydrogen Cloud Will Hit Milky Way

diewlasing points us to a story about a hydrogen cloud, eleven thousand light-years long, which will collide with the Milky Way in a devastating crossfire of shock waves and star formation...in 20-40 million years. Mark your calendars. At least it will give us something to watch while we're waiting for Andromeda to hit us in a few billion years. Hopefully, it will look at least this cool. "The detailed GBT study dramatically changed the astronomers' understanding of the cloud. Its velocity shows that it is falling into the Milky Way, not leaving it, and the new data show that it is plowing up Milky Way gas before it as it falls. 'Its shape, somewhat similar to that of a comet, indicates that it's already hitting gas in our Galaxy's outskirts,' Lockman said. 'It is also feeling a tidal force from the gravity of the Milky Way and may be in the process of being torn apart. Our Galaxy will get a rain of gas from this cloud, then in about 20 to 40 million years, the cloud's core will smash into the Milky Way's plane,' Lockman explained."

Comments

Shot in the Dark

[Amorymeltzer]

It seems to me that something with enough gas to create 1M stars akin to the Sun might have a noticeable impact on the revolutionary nature of the galaxy. Nothing astounding, probably akin to the added wobble of the Earth after the giant 2004 earthquake (the one that caused the tsunami) but it's probably something that, on the off chance we or some other life form is around, would be really awesome to observe. Also, assuming we don't have all the answers yet, seeing how the galaxy responds to such a sudden, massive change compared to our models could really tell us exactly how much mass there is, how it's distributed, etc.