Purple and green light seems to rain from the starry sky during an aurora, seen last Thursday from Ramsund, Norway.
Aurorae are created when charged particles from the sun flow along Earth's magnetic field lines. The particles hit Earth's atmosphere at the Poles and excite air molecules, which release the extra energy as light.
The solar probe had been tracking a region of magnetic activity on the sun's surface—a sunspot—when the region erupted to create what's called a solar prominence, seen above. Anchored to the sun's surface, the prominence stretched into the star's outer atmosphere, or corona, and eventually hurled material outward in a coronal mass ejection.
Image courtesy SDO/NASA
Dark brown and blue lunar lava plains, or maria, seem to stain the lunar landscape in color-enhanced pictures of the moon released September 10. Taken by NASA's Lunar Reconnaissance Orbiter, the new pictures combine data from seven distinct ultraviolet and visible wavelengths to show how different minerals affect the moon's reflective properties.
In general, mare regions of the moon are darker, because their rocks contain more iron oxide. But because one of the pictured regions—Mare Tranquillitatis (dark blue)—has rocks with higher concentrations of titanium oxide, the new color-enhanced image reveals where Tranquillitatis ends and Mare Serenitatis (dark brown) begins.
Image courtesy NASA/GSFC/Arizona State University
Maybe it's a star with an inferiority complex: From Earth, viewers need binoculars or a small telescope to spot the relatively faint object, even though it's part of our home galaxy, the Milky Way.
But for astronomers studying the dwarf galaxy PGC 39058, 14 million light-years away, the unnamed star is right in the line of sight, and it's so bright that its glare tends to partially obscure the background object.
In a new picture released September 13, the Hubble Space Telescope's piercing eye has managed to overcome the stellar scene-stealer, revealing almost all of the dwarf galaxy's individual stars, as well as several more distant galaxies in the background.
Image courtesy ESA/NASA
Burning in the Furnace
The galaxy known as NGC 1365 seems to hang in the sky 61 million light-years from Earth in the constellation Fornax, the Furnace, in a picture released by the European Southern Observatory on September 13.
NGC 1365 is also known as the Great Barred Spiral Galaxy due to its distinct central bar, believed to be a region where superhot gases are being ejected from a ring of material circling the galaxy's supermassive black hole. Astronomers think our Milky Way, seen from a distance, would look a lot like this 200,000-light-year-wide galaxy—just half the size.