This infrared composite image of the two hemispheres of Uranus was obtained with Keck adaptive optics. The images were obtained on July 11 and 12, 2004. The representative balance of these infrared images which were selected to display the vertical structure of atmospheric features gives a reddish tint to the rings, an artifact of the process. The North pole is at 4 o'clock. Lawrence Sromovsky, University of Wisconsin-Madison/ W. M. Keck Observatory/NASA
This high-resolution picture from the HiRISE camera on board the Mars Reconnaissance Orbiter shows twisting dark trails criss-crossing light-colored terrain on the Martian surface. Newly formed trails like these had presented researchers with a tantalizing mystery but are now known to be the work of miniature wind vortices known to occur on the red planet, in other words Martian dust devils. NASA/HiRISE/MRO/LPL/U. Arizona
The Sputnik 1 satellite is shown here on a rigging truck in the assembly shop in the fall of 1957 as a technician puts finishing touches on it. When the development of the first advanced scientific satellite, Object D, proved to be more difficult than expected, the Soviets decided to launch a simpler, smaller satellite. PS-1, or Sputnik 1, began development in November 1956. On October 4, 1957, Sputnik 1 successfully launched and entered Earth's orbit. NASA
Discovery spacewalker Danny Olivaz works during the STS-128 mission's first spacewalk. During the six-hour, 35-minute spacewalk, Olivas and astronaut Nicole Stott, removed an empty ammonia tank from the station's truss and temporarily stowed it on the station's robotic arm. Olivas and Stott also retrieved the European Technology Exposure Facility and Materials International Space Station Experiment from the Columbus laboratory module and installed them on Discovery's payload bay for return. NASA
The crescent moon rises in the early morning hours shortly before the Soyuz rocket is rolled out to the launch pad on March 24, 2009, at the Baikonur Cosmodrome in Kazakhstan. NASA/Bill Ingalls
A large, bright and complex convective storm that appeared in Saturn's southern hemisphere in mid-September 2004 was the key in solving a long-standing mystery about the ringed planet. The Dragon Storm was a powerful source of radio emissions during July and September of 2004. The radio waves from the storm resemble the short bursts of static generated by lightning on Earth. Cassini detected the bursts only when the storm was rising over the horizon on the night side of the planet as seen from the spacecraft; the bursts stopped when the storm moved into sunlight. Scientists have concluded that the Dragon Storm is a giant thunderstorm whose precipitation generates electricity as it does on Earth. NASA
Over 120 million years ago, a single mass of granite punched through the Earth's crust and intruded into the heart of the Namib Desert in what is now northern Namibia. Known as Daures or the burning mountain by Namibians, the mountain of rock also is called the Brandberg Massif and towers over the arid desert below. A ring of dark, steep-sided rocks forced upward during the mountain's arrival encircles the granite intruder. NASA/USGS
NASA's Hubble Space Telescope captures a rare view of the entire ring system of the planet Uranus, tilted edge-on to Earth. The rings were photographed with Hubble's Wide Field Planetary Camera 2 on August 14, 2007. The edge-on rings appear as spikes above and below the planet. NASA/M. Showalter/SETI Institute
Astronauts Steve Swanson and Joseph Acaba (not shown) prepared a worksite on March 23, 2009 so the STS-127 spacewalkers could more easily change out the Port 6 truss batteries. On the Japanese Kibo laboratory they installed a second Global Positioning Satellite antenna that will be used for the planned rendezvous of the Japanese HTV cargo ship in September. NASA
This artist's concept shows the smallest star known to host a planet. The planet, called VB 10b, was discovered using astrometry, a method in which small changes in the position of a star may indicate the gravitational presence of an orbiting planet. NASA
Islamic State militants are besieging the Syrian town of Kobane, leading tens of thousands of Kurds to flee into Turkey. Kurdish leaders accuse Turkey of supporting IS in order to curb Kurdish self-rule in Syria.
ByAlexander Christie-Miller, Correspondent
An 18-month-old ceasefire between Kurdish rebels and Turkey is increasingly imperiled by the crisis in the besieged town of Kobane in Syria, as well as by the Turkish government’s growing authoritarian streak.