Kathryn Johnston (Wesleyan University)

In 1994, astronomers discovered the Sagittarius Dwarf, a small dwarf galaxy that looked like it had been stretched into spaghetti-like strands thousands of light-years long. It turns out that the Sagittarius Dwarf has literally been torn into shredded loops by our Milky Way Galaxy's gravity field. This remarkable object is a classic example of the power of tides, whether it moves Earth's oceans or pulls apart entire galaxies. Using a galaxy similar to the Sagittarius Dwarf, the video shows how tidal interactions work to change the forms of whatever they touch.

Stealing stars

In this simulation, the Milky Way is represented as blue in the center with the small satellite galaxy orbiting around it. We follow the evolution of these two galaxies over several billion years. The dwarf galaxy is shown much larger than it would normally be so that we can see detail during the interaction. In fact, the Milky Way appears to be unaffected by the interaction, which is accurate since the Milky Way is so much more massive than the small dwarf galaxy. The colors in the dwarf show the density of stars being stripped from the satellite galaxy.

Charles Liu