NASA's Swift satellite has acquired the highest-resolution view of the neighbouring spiral galaxy M31. Also known as the Andromeda Galaxy, M31 is the largest and closest such galaxy to our own. It's more than 220,000 light-years across and lies 2.5 million light-years away in the constellation Andromeda. Dense clusters of hot, young, blue stars sparkle in the disk beyond the galaxy's smooth, redder central bulge. Star clusters are especially plentiful along a ring about 150,000 light-years across.
Simulation of the interactions between two galaxies as they pass by each other. The simulation contains 5000 Stars, the galaxies are simulated as scaled down version. The initial conditions resemble the Whirlpool Galaxy although no physical data from this galaxy was used in the simulation.
A fortuitous orbit of the International Space Station allowed the astronauts this striking view of Sarychev Volcano (Kuril Islands, Russia northeast of Japan) in an early stage of eruption on June 12, 2009. Sarychev Peak is one of the most active volcanoes in the Kuril Island chain, and it is located on the northwestern end of Matua Island.