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A Fire Rainbow Over New Jersey Credit & Copyright: Paul Gitto (Arcturus Observatory) Explanation: What is that inverted rainbow in the sky? Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc is created by ice, not fire. For a circumhorizon arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present. Furthermore, the numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight like a single gigantic prism. Therefore, circumhorizon arcs are quite unusual to see. Pictured above, however,...

Saturn's Rings from the Other Side Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: What do Saturn's rings look like from the other side? From Earth, we usually see Saturn's rings from the same side of the ring plane that the Sun illuminates them. Geometrically, in the above picture taken in April by the robot Cassini spacecraft now orbiting Saturn, the Sun is behind the camera but on the other side of the ring plane. This vantage point, specifically 17 degrees above the ring plane, gives a breathtaking views of the most splendid ring system in the Solar System....

Mars Soil Sample Ready to Analyze Credit: Phoenix Mission Team, NASA, JPL-Caltech, U. Arizona Explanation: What surprises are hidden in the soils of Mars? To help find out, the Phoenix Lander Phoenix Lander which arrived on Mars two weeks ago has attempted to place a scoop of soil in Phoenix's Thermal and Evolved-Gas Analyzer (TEGA). Pictured above, the dirt-filled scoop approaches one of TEGA's eight ovens. Once in the oven, a soil material will be baked and the emitted gasses categorized by a mass spectrometer. Quite possibly, some of the light colored material visible in the scoop has the same...

June's Young Crescent Moon Credit & Copyright: Miguel Claro Explanation: Serene skyviews were enjoyed across planet Earth earlier this week with a young crescent Moon low in the western sky just after sunset. Recorded on June 4, this colorful example includes a quiet beach in the foreground with the city lights of Lisbon, Portugal, and the Sintra Mountains along the horizon. Posing between cloud banks, the Moon's slender, sunlit arc represents only about 1 percent of the full lunar disc. The rest of the Moon's nearside is faintly visible though, illuminated by Earthshine. A waxing crescent Moon should also create...

Two-Armed Spiral Milky Way Illustration Credit: R. Hurt (SSC), JPL-Caltech, NASASurvey Credit: GLIMPSE Explanation: Gazing out from within the Milky Way, our own galaxy's true structure is difficult to discern. But an ambitious survey effort with the Spitzer Space Telescope now offers convincing evidence that we live in a large galaxy distinguished by two main spiral arms (the Scutum-Centaurus and Perseus arms) emerging from the ends of a large central bar. In fact, from a vantage point that viewed our galaxy face-on, astronomers in distant galaxies would likely see the Milky Way as a two-armed barred spiral similar to this...

Spitzer's Milky Way Credit: GLIMPSE, MIPSGAL, NASA, JPL-Caltech, Univ. Wisconsin Explanation: The Spitzer Space Telescope's encompasing infrared view of the plane of our Milky Way Galaxy is hard to appreciate in just one picture. In fact, more than 800,000 frames of data from Spitzer's cameras have now been pieced together in an enormous mosaic of the galactic plane - the most detailed infrared picture of our galaxy ever made. The small portion seen here spans nearly 8 degrees, roughly the apparent width of your fist held at arms length, across the galaxy's center. The full mosaic is 120 degrees...

Chasing the ISS Credit & Copyright: Jürgen Michelberger Explanation: Bathed in sunlight, the International Space Station (ISS) arced through the evening sky above the town of Lauffen in southern Germany on May 31st. The timing of the bright passage was about 10 minutes after the launch of the Space Shuttle Discovery on the STS-124 mission from Kennedy Space Center, Florida, in the southeastern US. Of course, Discovery was headed toward an orbital rendezvous with the ISS. In chasing after the space station, the shuttle also made a pass over Lauffen just 21 minutes after launch. With a camera fixed...

Unusual Light Patch Under Phoenix Lander on Mars Credit: Phoenix Mission Team, NASA, JPL-Caltech, U. Arizona Explanation: Is that ice under the Phoenix spacecraft on Mars? Quite possibly. Phoenix, which landed a week ago, was expected to dig under the Martian soil to search for ice, but the lander's braking rockets may already have uncovered some during descent. Pictured above is an image taken last week by the Robotic Arm Camera showing the unusual light-colored substance just in front of Phoenix's landing pad. Over the next few weeks, Phoenix will continue to photograph its surroundings, analyze the composition of this...

A Twisted Solar Eruptive Prominence Credit: SOHO Consortium, EIT, ESA, NASA Explanation: Ten Earths could easily fit in the "claw" of this seemingly solar monster. The monster, though, visible on the lower left, is a huge eruptive prominence seen moving out from our Sun. The above dramatic image taken early in the year 2000 by the Sun-orbiting SOHO satellite. This large prominence, though, is significant not only for its size, but its shape. The twisted figure eight shape indicates that a complex magnetic field threads through the emerging solar particles. Differential rotation inside the Sun might help account for the...

Descent of the Phoenix Credit: MRO-HiRISE, NASA, JPL, Univ. Arizona Explanation: In this sweeping view, the 10 kilometer-wide crater Heimdall lies on the north polar plains of Mars. But the bright spot highlighted in the inset is the Phoenix lander parachuting toward the surface. The amazing picture was captured on May 25th by the HiRISE camera onboard the Mars Reconnaissance Orbiter. Though the lander looks like it might be dropping straight into Heimdall, it is really descending about 20 kilometers in front of the crater, in the foreground of the scene. The orbiter was 760 kilometers away from Phoenix...

A Fog Bow Over Ocean Beach Credit & Copyright: Keith C. Langill (missionblvd.com) Explanation: What is that white arch over the water? What is being seen is a fogbow, a reflection of sunlight by water drops similar to a rainbow but without the colors. The fog itself is not confined to an arch -- the fog is mostly transparent but relatively uniform. The fogbow shape is created by those drops with the best angle to divert sunlight to the observer. The fogbow's relative lack of colors are caused by the relatively smaller water drops. The drops active above are so...

Dark Clouds of the Carina Nebula Credit: NASA, ESA, N. Smith (U. California, Berkeley) et al., and The Hubble Heritage Team (STScI/AURA) Explanation: What dark forms lurk in the mists of the Carina Nebula? These ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere. Pictured above is part of the most detailed image of the Carina Nebula ever taken, a part where dark molecular clouds are particularly prominent. The entire Carina Nebula spans over 300 light years and...

A New Horizon for Phoenix Credit: Phoenix Mission Team, NASA, JPL-Caltech, Univ. Arizona Explanation: This flat horizon stretches across the red planet as seen by the Phoenix spacecraft after yesterday's landing on Mars. Touching down shortly after 7:30pm Eastern Time, Phoenix made the first successful soft landing on Mars, using rockets to control its final speed, since the Viking landers in 1976. Launched in August of 2007, Phoenix has now made the northernmost landing and is intended to explore the Martian arctic's potentially ice-rich soil. The lander has returned images and data initially indicating that it is in excellent shape...

For about 300 years Jupiter's banded atmosphere has shown a remarkable feature to telescopic viewers, a large swirling storm system known as The Great Red Spot. In 2006, another red storm system appeared, actually seen to form as smaller whitish oval-shaped storms merged and then developed the curious reddish hue. Now, Jupiter has a third red spot ...

Jupiter's Three Red Spots Credit: NASA, ESA, M. Wong, I. de Pater (UC Berkeley), et al. Explanation: For about 300 years Jupiter's banded atmosphere has shown a remarkable feature to telescopic viewers, a large swirling storm system known as The Great Red Spot. In 2006, another red storm system appeared, actually seen to form as smaller whitish oval-shaped storms merged and then developed the curious reddish hue. Now, Jupiter has a third red spot, again produced from a smaller whitish storm. All three are seen in this image made from data recorded on May 9 and 10 with the Hubble...

Windblown NGC 3199 Credit & Copyright: Ken Crawford (Rancho Del Sol Observatory), Macedon Ranges Observatory Explanation: NGC 3199 lies about 12,000 light-years away, a glowing cosmic cloud in the southern constellation of Carina. The nebula is about 75 light-years across in this haunting, false-color view. Though the deep image reveals a more or less complete ring shape, it does look very lopsided with a much brighter edge at the lower right. Near the center of the ring is a Wolf-Rayet star, a massive, hot, short-lived star that generates an intense stellar wind. In fact, Wolf-Rayet stars are known to create...

Dangerous Sunrise on Gliese 876d Illustration Credit & Copyright: Inga Nielsen (Hamburg Obs., Gate to Nowhere) Explanation: On planet Gliese 876d, sunrises might be dangerous. Although nobody really knows what conditions are like on this close-in planet orbiting variable red dwarf star Gliese 876, the above artistic illustration gives one impression. With an orbit well inside Mercury and a mass several times that of Earth, Gliese 876d might rotate so slowly that dramatic differences exist between night and day. Gliese 876d is imagined above showing significant volcanism, possibly caused by gravitational tides flexing and internally heating the planet, and...

The Perseus Cluster of Galaxies Credit & Copyright: Jean-Charles Cuillandre (CFHT) & Giovanni Anselmi (Coelum Astronomia), Hawaiian Starlight Explanation: Here is one of the largest objects that anyone will ever see on the sky. Each of these fuzzy blobs is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies. The cluster is seen through a foreground of faint stars in our own Milky Way Galaxy. Near the cluster center, roughly 250 million light-years away, is the cluster's dominant galaxy NGC 1275, seen above as the large galaxy on the image left. A prodigious source...

On the Origin of Gold Illustration Credit : Dana Berry, NASA Explanation: Where did the gold in your jewelry originate? No one is completely sure. The relative average abundance in our Solar System appears higher than can be made in the early universe, in stars, and even in typical supernova explosions. Some astronomers have recently suggested that neutron-rich heavy elements such as gold might be most easily made in rare neutron-rich explosions such as the collision of neutron stars. Pictured above is an artist's illustration depicting two neutron stars spiraling in toward each other, just before they collide. Since neutron...

Logarithmic Spirals Image Credit: M101 - NASA, ESA, CFHT, NOAO; Typhoon Rammasun - MODIS, NASA Comparison: Lawrence Anderson-Huang (Ritter Astrophysical Obs., Univ. Toledo) Explanation: Uncomfortably close Typhoon Rammasun (right) and 25 million light-year distant galaxy M101 don't seem to have much in common. For starters, Rammasun was only a thousand kilometers or so across while M101 (aka the Pinwheel Galaxy) spans about 170,000 light-years, making them vastly dissimilar in scale, not to mention the different physical environments that control their formation and development. But they do look amazingly alike: each with arms exhibiting the shape of a simple and beautiful...