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2008 May 21 A Dangerous Sunrise on Gliese 876d Illustration Credit & Copyright: Inga Nielsen (Hamburg Obs., Gate to Nowhere)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 Mercuryand a mass several times that of Earth, Gliese 876d might rotate so slowly that dramatic differences exist between night and day. Gliese 876dis imagined above showing significant volcanism, possibly caused by gravitational tides flexing and internally heating the planet, and possibly more volatile during the day. The rising red dwarfstar shows expected stellar magnetic activity which includes dramatic and violent prominences. In the sky above, a hypothetical moon has its thin atmosphere blown away by the red dwarf’s stellar wind.Gliese 876d excites the imagination partly because it is one of the few extrasolar planetsknown to be close to the habitable zone of its parent star. mass loss

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spanning over 15 degrees and containing over 1,000 galaxies.At the distance of NGC 1275, this view covers about 7.5 million

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Doug Ellison,Mars Reconnaissance Orbiterspacecraft with information about the robotic

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2008 May 19 Flying Over the Columbia Hills of Mars Animated Illustration Credit: Randolph Kirk(USGS), MSSS,MER,What it would be like to fly over Mars?Combining terrain data from the orbiting Mars Global Surveyorspacecraft (now dormant) with information about the robotic Spirit rover currently rolling across Marshas resulted in a digital movie that showswhat a flight over the Columbia Hills might look like. Dark rippled sand dunes are highlighted against the Columbia Hills in the above opening image. Clicking on the above image, though, will launch you across Mars, approaching the Columbia Hills.On the far side of the hills, the dark sand dunes come into view. Soon you pass an unusual white-rimmed structure, slightly raised, known as Home Plate, the origin of which is currently unknown and being researched. Turning, you re-approach the hills from a different angle, this time zooming in on Spirit, a curious alien rover sent from planet Earth. A final zoom pans out over the region. This coming Sunday, NASA‘s Phoenix Landerwill attempt to set down near the icy North Pole of Marsand search for signs of ancient life.galaxy city

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2008 May 20 The Perseus Cluster of Galaxies Credit & Copyright: Jean-Charles Cuillandre(CFHT) &Giovanni Anselmi(Coelum Astronomia),Hawaiian StarlightHere is one of thelargest objects that anyone will ever see on the sky. Each of these fuzzy blobs is a galaxy, together making up thePerseus Cluster, one of the closest clustersof 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-yearsaway, is the cluster’s dominant galaxy NGC 1275,seen above as the large galaxy on the image left.A prodigious source ofx-rays and radio emission,NGC 1275 accretesmatter as gas and galaxies fall into it.The Perseus Cluster of Galaxiesis part of the Pisces-Perseus superclusterspanning over 15 degrees and containing over 1,000 galaxies.At the distance of NGC 1275, this view covers about 1.5 millionlight-years.dangerous planet

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2008 May 18 On the Origin of Gold Illustration Credit : Dana BerryWhere did the goldin 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 haverecently 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 neutron star collisions are also suggested as the origin of shortdurationgamma-ray bursts, it is possible that you already own a souvenir from one of the most powerful explosions in the universe.flying over mars

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collide. Since neutron star collisions

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2008 May 17

Explanation: Uncomfortably closeTyphoon Rammasun (right)and 25 million light-year distantgalaxy M101 don’t seem tohave much in common.For starters, Rammasun was only a thousand kilometers or soacross while M101 (aka the Pinwheel Galaxy)spans about 170,000 light-years, making them vastlydissimilar in scale, not to mention the differentphysical environments that control theirformation anddevelopment.But they do look amazingly alike: each with arms exhibiting theshape of a simple and beautiful mathematical curve known as alogarithmicspiral, a spiral whose separation grows in ageometricway with increasing distance from the center.Also known as theequiangular spiral, growth spiral, and Bernoulli’sspiral or spira mirabilis, this curve’srich properties have fascinatedmathematicianssince its discovery by 17th century philosopherDescartes.Intriguingly, this abstract shape is much more abundant in naturethan suggested by the striking visual comparison above.For example, logarithmic spirals can also describethe tracks of subatomic particlesin a bubble chamber,the arrangement ofsunflowerseeds and, of course,cauliflower.

ancient souvenir

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2008 May 16

Circles in the Sky Credit & Copyright: Jean-Marc Lecleire Explanation: Gazing skyward on a sunny day in May,photographer Jean-Marc Lecleire captured thisengaging displayof ice halosforming complete circles in the sky.Recorded with a fish-eye lens from a spot nearthe grandChâteau de Chambord in France,the picture looksstraight up, spanning almost 180 degrees fromhorizon to horizon.Surrounding the Sun is a haloformed by sunlight refracting throughhexagonal-shaped ice crystals inhigh, thin clouds.The halo is circular and exactly 22 degrees in radius,but it looks squashed because of thedistortionof the extremely wide-angle lens.Surrounding the zenith (the point directly above the observer)and always at the same altitude as theSun is a lovelyparhelic circle,caused by sunlightreflecting from ice crystals with nearly vertical faces.On average more common than rainbows,beautiful ice halos can often be seen in planet Earth’s skyby those who knowhow to lookfor them.

spira mirabilis

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2008 May 14 A Supply Ship Docks with the International Space Station ISS Expedition 16 Crew, NASALooking out a window of the International Space Station brings breathtaking views. Visible vistas include a vast and colorful Earth, a deep dark sky, and an occasional spaceship sent to visit the station. Visible early last month was a SoyuzTMA-12 spacecraft carrying not only supplies but also three newcomers. The three new astronauts were Expedition 17 commander Sergei Volkov, flight engineer Oleg Kononenko, and spaceflight participant So-yeon Yi. Yi returned to Eartha few days later, while Volkov and Konenenko are scheduled to return in a few months. The docking module pictured above involved the Pirs Docking Compartment. The Expedition 17 crew, including NASA flight engineer Gregory Chamitoff, will carry out repairs on the ISS, explore new methods of living in space, and conduct research in space including the effects of space radiation on vitamin molecules.sideways

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