One day, we'll use images like this waterfall of galaxies to figure out where to refuel our ships with dark energy. That's because this computer simulation of millions of galaxies flowing towards the red zone, the area with the highest mass, gives some clues to the location and nature of dark energy and dark matter. The image shows a "snapshot" of galaxies in the process of forming large-scale structures, 10 billion years ago. Click through for details.

The whole picture occupies a space of 100 million light years and this computer simulation "paints" the densest areas red. The yellow lines show the intensity of the galaxies' velocities as they fall into the highest-density area. The speed of the galaxies' rush towards the center of the structure depends on the the balance between dark matter, dark energy and the overall expansion of the universe. Astronomers are learning how to measure this "infall pattern" by using a large survey of galaxies at different epochs. [European Southern Observatory]