This mosaic image of Andromeda spiral galaxy -- showing explosive stars in its interior and cooler, dusty stars forming in its many rings -- combines observations from the Herschel Space Observatory taken in infrared light (the orange hues), and the XMM-Newton telescope captured in X-rays (the blues). Andromeda is our nearest large neighbor -- located about 2.5 million light-years away and holds nearly trillion stars. Our Milky Way galaxy contains about 200 - 400 billion stars.
NGC 4522 is a spectacular example of a spiral galaxy that is currently being stripped of its gas content. The galaxy is part of the Virgo galaxy cluster and its rapid motion within the cluster results in strong winds across the galaxy as the gas within is left behind. Scientists estimate that the galaxy is moving at more than 10 million kilometres per hour.
Mars south pole and beyond This sweeping view by ESA’s Mars Express extends from the planet’s south polar ice cap and across its cratered highlands to the Hellas Basin (top left) and beyond. - redits: ESA/DLR/FU Berlin
Active Galaxy Circinus lies 13 million light-years away in the southern constellation Circinus. This galaxy is designated a type 2 Seyfert, a class of mostly spiral galaxies that have compact centers and are believed to contain massive black holes. - Credit: NASA - National Aeronautics and Space Administration/ European Space Agency et al