A composite picture shows what the sun's atmosphere looked like on Wednesday, as seen in three different wavelengths of light. The picture—assembled from shots taken by the Atmospheric Imaging Assembly instrument aboard NASA's Solar Dynamics Observatory—includes a model of what the sun's magnetic field lines looked like at the time.
One of three main instruments on the orbiting observatory, the AIA takes pictures of the sun in ten wavelengths every ten seconds. Overlaying several such images can show how magnetic events, such as prominence eruptions and coronal mass ejections, generate motion across the solar orb.
Tropical storm Frank rages off the coast of Baja California, Mexico, on August 28 in a picture from NASA's unmanned Global Hawk hurricane-monitoring airplane. (Also see video of Hurricane Earl captured by astronauts.)
Global Hawk, which completed its first science flight earlier this year, can fly by itself for up to 30 hours, reaching altitudes of 60,000 feet (18,000 meters) and traveling as far as 11,000 nautical miles (20,000 kilometers). The robotic plane's mission is to study the atmosphere over the Atlantic and Pacific Oceans with unprecedented range and endurance. (Explore a Global Hawk interactive.)
"We can go to regions we couldn't reach or go to previously explored regions and study them for extended periods that are impossible with conventional [piloted] planes," mission scientist David Fahey, of the National Oceanic and Atmospheric Administration, said in a statement.
In a new picture, hundreds of young, bright stars heat up the gases of the Triangulum galaxy, creating a distinctive red glow.
The image is being billed as the sharpest shot yet of the star-forming region known as NGC 604. Released August 30, the view combines data from a wide range of wavelengths, captured by the NASA/ESA Hubble Space Telescope.
The star "metropolis" is Triangulum's largest star nursery, stretching about 1,500 light-years across. Blistering radiation from the infant stars not only lights up the neighborhood but also carves out bubbles in the surrounding hydrogen gas, giving NGC 604 its complex structure.
The turquoise lagoon of French Polynesia's Mataiva atoll stands out against the dark blue of the surrounding Pacific Ocean in an image taken by an astronaut on August 13.
The atoll—a ring-shaped island enclosing a central lagoon—is part of the Tuamotu Archipelago, the largest chain of atolls on Earth. Mataiva is unique in that its central lagoon includes a network of ridges (white, center) and small basins formed by eroded coral reefs, according to NASA's Earth Observatory, which released the photo on August 30. (See more pictures of French Polynesia.)
Forest (greenish brown) covers much of the outside perimeter of the six-mile-long (ten-kilometer-long) atoll.
Fiery clouds billow during an August 31 test of Development Motor-2, the largest and most powerful solid rocket motor ever designed for flight, according to the NASA website.
Information collected during the successful experiment—conducted in Brigham City, Utah—will help scientists evaluate the motor, which was built to generate 3.6 million pounds of thrust.
The motor may be used to launch future heavy vehicles, according to NASA.