By George Musser
(Click here for original article.)
This video shows the spiral shape of our galaxy and two of its small satellite galaxies, the Large and Small Magellanic Clouds (to the left). The satellites orbit the main galaxy and, in the process, trigger slow-motion waves in it. On a human time scale, those waves look like a static warp in the galactic outskirts. The strange thing is that the satellites are too lightweight to have such a dramatic effect. Astronomers recently demonstrated that their gravity is greatly amplified by dark matter (which this video does not show -- it is, after all, dark).