Looking like a pair of eyeglasses only a rock star would wear, this nebula brings into focus a murky region of star formation. NASA's Spitzer Space Telescope exposes the depths of this dusty nebula with its infrared vision, showing stellar infants that are lost behind dark clouds when viewed in visible light. Best known as Messier 78, the two round greenish nebulae are actually cavities carved out of the surrounding dark dust clouds. The extended dust is mostly dark, even to Spitzer's view, but the edges show up in mid-wavelength infrared light as glowing, red frames surrounding the bright interiors. Messier 78 is easily seen in small telescopes in the constellation of Orion, just to the northeast of Orion's belt, but looks strikingly different, with dominant, dark swaths of dust. Spitzer's infrared eyes penetrate this dust, revealing the glowing interior of the nebulae. A string of baby stars that have yet to burn their way through their natal shells can be seen as red pinpoints on the outside of the nebula. Eventually these will blossom into their own glowing balls, turning this two-eyed eyeglass into a many-eyed monster of a nebula. This is a three-color composite that shows infrared observations from two Spitzer instruments. Blue represents 3.6- and 4.5-micron light, and green shows light of 5.8 and 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer. Image Credit: NASA/JPL-Caltech

High-mass stars are important because they are responsible for much of the energy pumped into our galaxy over its lifetime.
Credit: X-ray: NASA/CXC/CfA/S.Wolk; IR: NASA/JPL/CfA/S.Wolk

Richardson Crater is well-known among Mars scientists for its spectacular dunes. These dunes are located around -72 degrees in latitude; if they were on Earth they'd be well south of the Antarctic Circle! Because of their extreme southern positioning, they endure dramatic temperature changes over the course of the Martian year. The HiRISE team attempts to monitor this area as these dunes get covered by seasonal frost in the fall and defrost in the spring, taking multiple images over the same locations in order to better understand the structure and evolution of these beautiful landforms. This image was taken close to the Southern hemisphere autumnal equinox, the end of Southern hemisphere Summer and beginning of autumn. Unlike that observed on Earth, the frost seen on the Richardson Crater dunes is composed of carbon dioxide, and sublimates (goes directly from a solid to a gas) rather than melts. At the time of this image, the frost has likely disappeared to its greatest extent and will begin to re-acummulate soon. Wide, dark streaks are visible extending from the crests of the dunes, likely due to movement of material as the dunes defrosted or to wind transportation of surface particles. Numerous dust devil tracks are still visible as thin, dark, criss-crossing marks, although these will gradually be covered by carbon dioxide frost as Southern hemisphere winter sets in. The subimage is approximately 1 kilometer (about 0.62 miles) across. To see the previous image taken at this same location, taken in early Southern Hemisphere Spring as the dunes were thawing, see ESP_011785_1075. To take a look at other impressive dunes from various locations within Richardson Crater, see ESP_012774_1080, PSP_004230_1080, and ESP_012985_1075. Written by: Kristin Block   (5 October 2011)
Credits: NASA/JPL/University of Arizona

Acquired September 15, 2000, this natural-color image shows Aniakchak National Monument in Alaska, home to an old caldera, and even older fossils.
Credit: NASA Earth Observatory

Credit: NOAA Space Weather Prediction Center