This natural color composite photo of Saturn was taken by NASA’s Cassini spacecraft. (NASA)

A baby Adélie penguin nuzzles up to its mother inside one of three bird colonies on Ross Island near Antarctica. (Penguinscience.com)

This is Robonaut 2-R2, the first dexterous humanoid robot in space, in an image taken inside the International Space Station.  NASA astronaut Kevin Ford’s reflection can be seen on R2′s helmet visor. (NASA)

Lava from a lava pond, below the peak, flows on the north side of Hawaii’s Kilauea volcano. (USGS)

Photo illustration of the magnificent spiral galaxy M106, assembled using data from the Hubble Space Telescope. (NASA)

This photograph, taken through a microscope, is of a brown fat cell (brown adipocyte) taken from a muscle stem cell. (Alessandra Pasut, Ottawa Hospital Research Institute)

Technicians prepare NASA’s Landsat Data Continuity Mission (LDCM) satellite for its scheduled launch on Monday, Feb. 11 at 1800 UTC. (NASA)

Sockeye salmon migrate from salt water to fresh water in British Columbia’s Fraser River, changing from their silvery ocean colors to red in fresh water. (Tom Quinn, University of Washington)

The Orion nebula is showcased in this sweeping image from NASA’s Wide-field Infrared Survey Explorer (WISE). (NASA)

An Atlas V rocket carrying NASA’s Tracking and Data Relay Satellite-K (TDRS-K) streaks past a building at the Kennedy Space Center in Florida. (NASA)

Artist’s concept of a new view of the Milky Way. Scientists have discovered the Milky Way’s elegant spiral structure is dominated by two arms wrapping off the ends of a central bar of stars. Our galaxy was previously thought to possess four major arms. (NASA)

Native to Madagascar, this is an indri, one of the largest living lemurs in the world. (Meredith Barrett)

This is a Spallation Neutron Source cavity assembly in the clean room the Thomas Jefferson National Accelerator Facility in Virginia. It’s a piece of a particle accelerator scientists use to provide the most intense pulsed neutron beams in the world. (Jefferson Lab)

NASA will use this spacecraft, seen here with its solar panels deployed  in a clean room at Lockheed Martin in Sunnyvale, California, for its Interface Region Imaging Spectrograph (IRIS) mission scheduled for launch this April. (Lockheed Martin)

Immune system cells, called macrophages, normally engulf and kill intruding bacteria but sometimes the microbes, shown in red, find a way to escape into the interior of the cell where it can multiply and invade other cells. (Miao lab, UNC School of Medicine)

A large male purple marsh crab (Sesarma reticulatum) clips cordgrass with its claws. These crabs are nocturnal and typically live in burrows during the day to stay moist and avoid predators. (Tyler Coverdale)

This is a single five-minute exposure taken recently in Buenos Aires on an Argentinian summer night. It shows not only Earth clouds but starry clouds, the pinkish glow of the Carina Nebula and Small Magellanic Clouds. The line arcing from the center of the right side to the lower left is the orbiting International Space Station. (Photo & Copyright: Luis Argerich)

Before workers with NASA’s US Antarctic Program are sent into the field, they must first undergo training to endure the harsh Antarctic conditions. Here’s a look at their training camp site, set up on the Ross Ice Shelf ,the largest ice shelf of Antarctica. ( NASA)

Found in the waters surrounding the Philippines, a moray eel poses for a photo. (M. J. Costello)

After four months aboard the International Space Station, three Expedition 33 crewmembers returned to Earth in their Soyuz spacecraft, making a rare night landing in a remote area of Kazakhstan. (NASA)

Antarctica’s Sheldon Glacier with Mount Barre in the background. This photo was taken by scientists participating in a new NASA/British Antarctica Survey studying the effects of climate change on Antarctic sea ice cover. (British Antarctic Survey)

The Large Underground Xenon (LUX) detector is an important tool in scientists’ search for dark matter, one of nature’s most elusive particles.  This is a top-down view of the copper photomultiplier tube mounting structure, a key component of the detector. (Lawrence Livermore National Laboratory)

An adult female walrus sits on an ice floe just off the Eastern Chukchi Sea in Alaska. (S.A. Sonsthagen/USGS)

The Sun recently experienced two prominent eruptions, which occurred one after the other over a four-hour period. Fortunately, the expanding particle clouds shooting into space weren’t directed at Earth. (NASA)

A view of the countryside in Binghamton, NY as seen from inside a US National Weather Service radar radome (which protects radar components from the elements). The weather radar was recently taken offline so that repairs could be made. (NOAA/NWS)

Titan, the world’s most powerful and fastest supercomputer, is located at the Oakridge National Laboratory in Tennessee. Titan’s computational capability is on par with each of the world’s 7 billion people being able to carry out 3 million calculations per second. (Oakridge National Laboratory)

A group of galaxies glows like fireflies on a dark night in this image snapped recently by the Hubble Space Telescope. (NASA)

A cluster of lightning over a US National Severe Storms Lab Probe minivan which measures weather statistics as it travels through storms. (NOAA)

Scientists at the U.S. Department of Energy’s (DOE) Ames Laboratory are working to more effectively remove a rare earth element (group of closely related metallic elements) called neodymium from the mix of other materials in a magnet. Here rare-earth magnet scraps are melted in a furnace with magnesium. (DOE/Ames Laboratory)

Astronauts on the International Space Station recently used a digital camera to capture several hundred photographs of the Aurora Australis, or the “southern lights.”  (Photo: NASA)

A research team from the University at Buffalo in New York, studying glaciers at Ayr Lake on Baffin Island, Canada, found the island’s glaciers reacted rapidly to past climate change, providing what they say is a rare glimpse into glacier sensitivity to climate events. (Photo: Jason Briner via NSF)

The lava lake in the Halemaʻumaʻu crater of Hawaii’s Kīlauea volcano spits and sputters with occasional bursts of volcanic material. (Photo: USGS)

Two galaxies becoming one. This is a Hubble telescope photo of NGC 2623, two galaxies in the final stages of a titanic galaxy merger, located some 300 million light-years away. (Photo: NASA)

NASA’s Small Multi-Purpose Research Facility ( SMiRF ) evaluates the performance of thermal protection systems required to provide long-term storage and transfer of cryogenic propellants in space. Recent testing was done over a range of temperatures as low as -253°C and tank pressures from 20-80 psia (pounds per square inch absolute). (Photo: NASA & Bridget R. Caswell (Wyle Information Systems, LLC))

The Soyuz rocket carrying ISS Expedition 33 crew members launches to the International Space Station from the Baikonur Cosmodrome in Kazakhstan, on Tuesday, Oct. 23, 2012. (Photo: NASA)

Paragorga arborea, also known as bubblegum coral, is an abundant coral species that can grow massive colonies, and has been found at polar, subpolar, and subtropical regions of all of the world’s oceans. It can reach up to eight meters in height and live up to 100 years.  (Photo: NOAA/MBARI)

A look at the center of our galaxy. Using a massive nine-gigapixel image, (from the VISTA infrared survey telescope at ESO’s Paranal Observatory in Chile) an international team of astronomers has created a catalog of more than 84 million stars located in the central parts of the Milky Way. The image is so large that, if printed with the resolution of a typical book, it would be 9 meters long and 7 meters tall. (Photo: ESO/VVV Consortium/Ignacio Toledo)

This is a robot at the US Department of Energy’s Lawrence Berkeley National Laboratory that has been coded with PaR-PaR, which stands for Programming a Robot; a simple, high-level, biology-friendly, robot-programming language that allows researchers to make better use of liquid-handling robots and thereby make possible experiments that otherwise might not have been considered. (Photo: Roy Kaltschmidt, Berkeley Lab)

A bright particle of material found in a hole dug by the Curiosity Martian rover caused a bit of concern at NASA’s Jet Propulsion Laboratory because another similar object, found nearby, was identified as a piece of debris from the spacecraft. However, the mission’s science team assessed the bright particles in this scooped pit to be native Martian material rather than spacecraft debris. (Photo: NASA)

NASA/Goddard physicist Babak Saif checks an oscilloscope as he works on a project that would be capable of detecting, with atomic-level precision, gravitational waves that were predicted in Einstein’s general theory of relativity. (Photo: NASA)

NASA’s Swift satellite recently detected a growing flow of high-energy X-rays from somewhere near the center of our galaxy. The outburst, pictured in this illustration, was produced by a rare X-ray nova and announced the presence of a previously unknown stellar-mass black hole. (Image: NASA)

A school of Kokanee Salmon returns to the streams from which they were hatched. There, they select a mate, spawn and die. As the salmon make their annual fall migration, both sexes turn from their usual silver/blue color to a brilliant red. (Photo: United States Forest Service)

This image from the right Mast Camera (Mastcam) of NASA’s Mars rover Curiosity shows sand and dust lifted by the rover’s first use of the scoop on its robotic arm. (Photo: NASA)

A 700kg crocodile called Rex calmly waits just beneath the water’s surface for some food after coming out of a three-month hibernation at the Wild Life Sydney Zoo in Sydney, Australia. (Photo: AP)

No, these aren’t miniature UFOs. The tiny cube-shaped satellites were released into space from the International Space Station’s Kibo laboratory. One of these little CubeSats was developed by student interns at San Jose State University and will be used for a communications experiment (Photo: NASA)

The interior of the neutrino detector at Daya Bay in the People’s Republic of China, where a multi-national team of researchers from China, the United States, Taiwan, and the Czech Republic are studying neutrino oscillations. Neutrinos are electrically neutral elementary subatomic particles that can travel through great distances of matter without being affected by it. (Photo: Lawrence Berkeley National Laboratory)

This combined image from NASA is of the Helix Nebula, which has also been called the “Eye of God.” At the nebula’s heart is a dying star. In its death throes, the star’s outer layers unravel into space and are set aglow by powerful ultraviolet radiation pumped out by its hot stellar core. (Photo: NASA)

A monarch butterfly stops for a rest during its fall migration. The butterfly can journey up to nearly 5,000 km to its winter home in Mexico or Southern California. In the spring, they make another epic trip as they return to areas up north. (Photo: USDA)

This time-exposure photo shows the Falcon 9 SpaceX rocket lifting off from the Cape Canaveral Air Force Station in Cape Canaveral, Florida. The rocket, with its Dragon space capsule payload, just made its first commercial delivery of supplies to the International Space Station. (Photo: AP)

The Z machine, the largest X-ray generator in the world, is located in Albuquerque, New Mexico. It concentrates electrical energy, turning it into short pulses of enormous power, which can then be used to generate X-rays and gamma rays. (Photo: Image: Randy Montoya/Sandia National Laboratories)

The farthest-ever view of the universe. Hubble’s Extreme Deep Field (XDF) is a composite made from 2,000 images taken by the Hubble Space Telescope over a 10-year period. (Credit: NASA)

This orange elephant ear sponge, or Agelas clathrodes, was found in NOAA’s Flower Garden Banks National Marine Sanctuary in the Gulf of Mexico. (Photo: NOAA)

The Curiosity rover may found evidence of an ancient stream bed. This picture of a Martian rock outcrop called Link has characteristics consistent with a rock formed by water deposits and transport. (Photo: NASA)

African penguins gather to keep warm as some are fed sardines at the South African Foundation for the Conservation of Coastal Birds.  The penguins were recently found covered in oil on Robben Island, Cape Town, South Africa. (Photo: AP)

Space shuttle Endeavour, atop the Shuttle Carrier Aircraft, comes in for a landing at the Los Angeles International Airport. It was the final scheduled ferry flight of the US Space Shuttle Program. Endeavour will be placed on public display at the California Science Center in Los Angeles.  (Photo: NASA)

A high-powered laser – based at the University of California, Santa Barbara – is used to study the world at the atomic level. (Photo: UCSB/Susumu Takahashi)

A cardiac balloon catheter embeded with a mesh of sensors and electronics is being developed by researchers at the University of Illinois. When placed inside a cardiac patient’s heart, a device such as this may allow for a better and more efficient diagnosis and treatment of arrhythmias. (Photo: J. Rogers, University of Illinois)

Technicians and scientists in the clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, check out one of the first two flight mirrors that will be used on the new Webb Space Telescope. (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, 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 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, 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 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)

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 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)

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) 

A close look at active lava flows produced by Hawaii’s Kīlauea Volcano (Photo: USGS Hawaiian Volcano Observatory)