Science Images of the Week

A mosaic of images of Saturn and its moon, Titan, taken by NASA's Cassini spacecraft. Seasons have changed on Saturn, the azure blue in the planet’s northern hemisphere is now fading while the southern hemisphere is now taking on a bluish hue. Scientists say these changes are likely due to the reduced intensity of ultraviolet light and the haze it produces in the southern hemisphere as winter approaches, and the increasing intensity of ultraviolet light and haze production in the northern hemisphere as summer approaches. (Photo: NASA)

A composite of a mosaic of images of Saturn and its moon, Titan, taken by NASA’s Cassini spacecraft. Seasons have changed on Saturn, the azure blue in the planet’s northern hemisphere is now fading while the southern hemisphere is now taking on a bluish hue. Scientists say these changes are likely due to the reduced intensity of ultraviolet light and the haze it produces in the southern hemisphere as winter approaches, and the increasing intensity of ultraviolet light and haze production in the northern hemisphere as summer approaches. (Photo: NASA)

The Soyuz TMA-04M spacecraft with ISS Expedition 32 Commander Gennady Padalka of Russia, NASA Flight Engineer Joe Acaba and Russian Flight Engineer Sergei Revin lands in a remote area near the town of Arkalyk, Kazakhstan, on Sept. 17, 2012 (Kazakhstan time). (Photo: NASA/Carla Cioffi)

The Soyuz TMA-04M spacecraft, carrying two cosmonauts and a NASA flight engineer, lands in a remote area near the town of Arkalyk, Kazakhstan, on Sept. 17, 2012. (Photo: NASA)

NASA Flight Engineer Joe Acaba signs the side of his Soyuz TMA-04M spacecraft that brought him and his crew mates back to Earth on September 17, 2012. Acaba, along with Gennady Padalka and Sergei Revin of Russia returned from four months on board the International Space Station where they served as members of the Expedition 31 and 32 crews. (Photo: NASA/Carla Cioffi)

NASA Flight Engineer Joe Acaba signs the side of the Soyuz TMA-04M spacecraft which brought him and his crew mates back to Earth on Sept. 17, 2012. Acaba, along with Gennady Padalka and Sergei Revin of Russia, returned from four months on board the International Space Station where they served as members of the Expedition 31 and 32 crews. (Photo: NASA)

A giraffe calf was recently born at the Dickerson Park Zoo in Springfield, MO. Here, the baby giraffe sits while mother licks its head (Photo: Dickerson Park Zoo)

A giraffe calf, which was recently born at the Dickerson Park Zoo in Springfield, Missouri, with its mother. (Photo: Dickerson Park Zoo)

With the Martian landscape in the background this is the Mars Hand Lens Imager (MAHLI), one of seventeen cameras on NASA’s Curiosity rover. The photo was recently taken by the rover’s Mast Camera – MastCam (Photo: NASA/JPL-Caltech/MSSS)

With the Martian landscape in the background, this is the Mars Hand Lens Imager (MAHLI), one of 17 cameras on NASA’s Curiosity rover. The photo was taken by the rover’s Mast Camera – MastCam (Photo: NASA)

The Heat Island Group at Lawrence Berkeley National Laboratory works to cool buildings, cities, and the planet by making roofs, pavements, and cars cooler in the sun. Here, Jordan Woods takes measurements of new cooler pavement coating. Other sample pavement coatings can be seen behind him. (Photo: Lawrence Berkeley National Laboratory)

While the Mars rover Curiosity is the center of attention right now, Opportunity, a rover that has been on the Red Planet since January 2004 recently sent images of a collection of little spheres that scientists nicknamed ‘blueberries’. These puzzling little objects were found on an outcrop of rock called "Kirkwood" and each is about 3 millimeters in diameter. (NASA/JPL-Caltech/Cornell Univ. / USGS/Modesto Junior College)

Opportunity, a rover which has been on Mars since January 2004, captured this image of little spheres that scientists nicknamed ‘blueberries.’ These puzzling little objects were found on an outcrop of rock called “Kirkwood” and each is about 3 millimeters in diameter. (Photo: NASA)

An extreme close up of a wild tomato’s trichomes, hair-like protrusions, that produce a mixture of special chemicals that shape the interactions between the plant and its environment some of which act as the first line of defense against pests. (Photo: Michigan State University)

An extreme close up of a wild tomato’s trichomes, hair-like protrusions that produce a mixture of special chemicals which shape the interactions between the plant and its environment, some of which act as the first line of defense against pests. (Photo: Michigan State University)

Astronomers recently discovered two gas giant planets orbiting stars in the Beehive cluster, a collection of about 1,000 tightly packed stars. The planets are the first ever found around sun-like stars in a cluster of stars. This is an artist’s conception of one of the gas giants to the right of its sun-like star, and all around, the stars of the Beehive cluster shine brightly in the dark. (Image: NASA/JPL-Caltech)

Shown above are the spiral galaxies NGC 3788 (top) and NGC 3786 (bottom) in the constellation Ursa Major (home of the Big Dipper). These two galaxies, like many found throughout the Sloan Digital Sky Survey, are gravitationally interacting. (Photo: Sloan Digital Sky Survey)