Space Photos This Week: Aurora "Rain," Moon Pit, More

Spitfire Sun

Image courtesy SDO/NASA

On September 8 NASA's Solar Dynamics Observatory witnessed the sun spitting a bright burst of charged gas into space.

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.

Published September 15, 2010

Lunar Hues

Image courtesy NASA/GSFC/Arizona State University

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.

Published September 15, 2010

Shining Star

Image courtesy ESA/NASA

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.

Published September 15, 2010

Burning in the Furnace

Image courtesy ESO

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.

Published September 15, 2010

Moon Pit

Image courtesy NASA/GSFC/Arizona State University

Boulders dot the otherwise smooth floor of the Mare Tranquillitatis pit—one of three lunar "skylights" announced last year—in a new picture from NASA's Lunar Reconnaissance Orbiter released September 14.

The Japanese lunar probe Kaguya had found the pit craters have an average width of about 330 feet (100 meters). The openings were likely created by ancient volcanic activity.

In the new NASA shot, the length of the stark shadow created by the angle of sunlight allowed astronomers to calculate the pit's depth: a bit more than 328 feet (100 meters).

Published September 15, 2010

Seeing Green

Photograph by Yuichi Takasaka, TWAN

An aurora borealis—aka northern lights—is reflected in British Columbian waters on September 6.

The sun's activity has been ramping up over the past several months, and strong bursts of particles called coronal mass ejections have been sending even more aurora-sparking material toward Earth.

Published September 15, 2010