Sunlight casts a crescent shadow on the floor of an underground cavern in a recently released picture of a Martian "skylight." This round opening likely leads to a lava tube, which is created when lava solidifies on the surface but keeps flowing underground. Eventually the lava drains away, leaving an empty cave.
Snapped by NASA's Mars Reconnaissance Orbiter, the picture revealed that the skylight is 115 feet (35 meters) across. The shadow helped scientists calculate that the cave floor is about 65 feet (20 meters) below the surface.
Image courtesy U-Arizona/NASA
Galaxy Gets Bent
A galaxy slightly smaller than our own Milky Way is getting its arm twisted, and a cosmic bully may be to blame.
As seen in a recently released NASA/ESA Hubble Space Telescope picture, the galaxy NGC 2146 has one of its spiral arms bent at a 45-degree angle, so that the dense limb has looped in front of the galaxy's core, as seen from Earth.
The most likely explanation is that the gravity of an unidentified nearby galaxy is disturbing NGC 2146's arm, causing the galaxy to warp.
Image courtesy ESA/NASA
Dawn light casts a rosy hue on two freshwater lagoons near Kaliningrad, Russia, in a picture taken by an astronaut aboard the International Space Station and released August 22. The lagoons are shielded from the open waters of the Baltic Sea (left) by skinny spits of land that curve on either side of the peninsula.
The lagoon at top is Kurshsky Bay—also called the Curonian Lagoon—in nearby Lithuania. The body of water at the bottom is Vistula Lagoon.
Photograph courtesy NASA
Dark shadows help define craters on the face of the large asteroid Vesta, named for the Roman virgin goddess of hearth and home, in a picture released August 22.
NASA's Dawn spacecraft snapped the shot from the satellite's orbit around Vesta. The space rock is part of our solar system's main asteroid belt, between the orbits of Mars and Jupiter. The massive asteroid is considered a protoplanet, a would-be planet whose growth was interrupted in infancy by the formation of Jupiter.
Image courtesy NASA/Caltech/UCLA/MPS/DLR/IDA
Scientist Edson Ramirez was in for a surprise August 16 as he was studying glaciers in the Bolivian Andes: A large object fell from the sky, leaving a trail of smoke over the mountain peaks known as Huayna Potosí and Tuni Condoriri.
Based on Ramirez's picture, planetary scientist Rubber Munoz Sanchez, of the Max Schreier Planetarium in La Paz, told Reuters that he thinks the object was a meteor up to 20 inches (50 centimeters) wide.
Photograph by Edson Ramirez, Reuters
A large rock nicknamed Ridout dominates the rim of Odyssey crater—itself on the rim of the much larger Endeavour crater—in an August 13 picture by the Mars rover Opportunity. The shot is among the first pictures taken by the rover since it arrived at Endeavour on August 9.
Ridout is thought to be a piece of material ejected from Odyssey during the impact that formed the comparatively small basin. The rock is 4.9 feet (1.5 meters) long—roughly the same size as Opportunity.
Image courtesy Caltech/Cornell/ASU/NASA
Stars Over Sugar Lake
Star trails swirl through candy-colored auroras in a sweet new view of Sugar Lake in British Columbia, Canada, released this week.
Taken in July, the long-exposure picture illustrates how stars seem to rotate around what's known as the celestial north pole, an imaginary point in the sky closest to the star Polaris—the dot of light at top left—that seems to intersect Earth's axis of rotation.