New computer simulations show that winds generated by supernovas, which are the explosions of massive stars, can push stars out from the center of a dwarf galaxy. This simulation of supernova winds redistributes both ordinary matter and invisible dark matter in a way that almost perfectly matches observations of the way matter is distributed in actual dwarf galaxies.

Previous attempts to model galaxy formation based on the highly successful theory of cold dark matter — which states that invisible material must account for 85 percent of the mass of the universe — have done “an awesome job” of explaining such global properties as where, when and how many galaxies should form, notes Governato. But the models have failed to reproduce some of the key features of individual galaxies.

Successful simulations of supernova winds can help in understanding star formation because supernovas explode close to where massive stars are born. At the same time, Simon White, director of the institute, notes that it’s unclear exactly how the particular star-forming recipe used by Governato and his colleagues differs from those of other teams and why it’s achieved such a good match with observations.

The Martian "trees" are actually dark basaltic sand pushed to the surface of sand dunes by sun-heated solid carbon dioxide ice, or dry ice, sublimating directly into vapor. I assume you would probally see shadows if they were actually protruding.

This new image of Mars taken by NASA's Mars Reconnaissance Orbiter.

Credit: NASA/JPL/University of Arizona.