Leonids and Leica

This lovely view from northern Spain at Cape Creus on the easternmost point of the Iberian peninsula, looks out across the Mediteranean and up into the stream of the 2002 Leonid meteor shower. The picture is a composite of thirty separate one minute exposures taken through a fisheye lens. Over 70 leonid meteors are visible, some seen nearly head on. Bright Jupiter is positioned just to the right of the shower's radiant in Leo. Perched on the moonlit rocks at the bottom right, Leica, the photographers' dog, seems to be watching the on going celestial display and adds a surreal visual element to the scene. The 2006 Leonid meteor shower will be much less intense than in 2002, but will be near its predicted peak this weekend. Sky watchers will have their best view under dark skies in early morning hours with Leo rising above the eastern horizon.

http://antwrp.gsfc.nasa.gov/apod/ap061118.html

Star EGGs in the Eagle Nebula

Where do stars form? One place, star forming regions known as "EGGs", are uncovered at the end of this giant pillar of gas and dust in the Eagle Nebula (M16). EGGs, short for evaporating gaseous globules, are dense regions of mostly molecular hydrogen gas that fragment and gravitationally collapse to form stars. Light from the hottest and brightest of these new stars heats the end of the pillar and causes further evaporation of gas - revealing yet more EGGs and more young stars. This picture was taken by the Wide Field and Planetary Camera on board the Hubble Space Telescope.

http://antwrp.gsfc.nasa.gov/apod/ap061022.html

Hidden Galaxy IC 342

Similar in size to other large, bright spiral galaxies IC 342 is a mere 7 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is almost hidden from view behind the veil of stars, gas and dust clouds in the plane of our Milky Way galaxy. Even though IC 342's light is dimmed by intervening cosmic clouds, this remarkably sharp telescopic image traces the galaxy's own obscuring dust, blue star clusters, and glowing pink star forming regions along spiral arms that wind far from the galaxy's core. IC 342 may have undergone a recent burst of star formation activity and is close enough to have gravitationally influenced the evolution of the local group of galaxies and the Milky Way.

http://antwrp.gsfc.nasa.gov/apod/ap061005.html

Orbiting a Red Dwarf Star

This artist's concept of a gas giant planet orbiting a red dwarf K star shows a planet has not been directly imaged, but its presence was detected in 2003 microlensing observations of a field star in our galaxy. Gravitational microlensing happens when a foreground star amplifies the light of a background star that momentarily aligns with it. Follow-up observations by Hubble Space Telescope in 2005 separated the light of the slightly offset foreground star from the background star. This allowed the host star to be identified as a red dwarf star located 19,000 light-years away. The Hubble observations allow for the planet's mass to be estimated at 2.6 Jupiter masses. The characteristics of the lensing event show that the planet is in a Jupiter-sized orbit around its parent red star. The rings and moon around the gas giant are hypothetical, but plausible, given the nature of the family of gas giant planets in our solar system.

http://www.nasa.gov/multimedia/imagegallery/image_feature_671.html

An Unwelcome Place for New Stars

This artist's concept depicts a supermassive black hole at the center of a galaxy. NASA's Galaxy Evolution Explorer found evidence that black holes -- once they grow to a critical size -- stifle the formation of new stars in elliptical galaxies. Black holes are thought to do this by heating up and blasting away the gas that fuels star formation.

The blue color here represents radiation pouring out from material very close to the black hole. The grayish structure surrounding the black hole, called a torus, is made up of gas and dust. Beyond the torus, only the old red-colored stars that make up the galaxy can be seen. There are no new stars in the galaxy.

http://www.nasa.gov/multimedia/imagegallery/image_feature_670.html

Comet SWAN Brightens

A newly discovered comet has brightened enough to be visible this week with binoculars. The picturesque comet is already becoming a favored target for northern sky imagers. Pictured above just last week, Comet SWAN showed a bright blue-green coma and an impressive tail. Comet C/2006 M4 (SWAN) was discovered in June in public images from the Solar Wind Anisotropies (SWAN) instrument of NASA and ESA's Sun-orbiting SOHO spacecraft. Comet SWAN, near magnitude six, will be visible with binoculars in the northeastern sky not far from the Big Dipper over the next few days before dawn. The comet is expected to reach its peak brightness this week. Passing its closest to the Sun two days ago, Comet SWAN and will be at its closest to the Earth toward the end of this month. Comet SWAN's unusual orbit appears to be hyperbolic, meaning that it will likely go off into interstellar space, never to return.

http://antwrp.gsfc.nasa.gov/apod/ap061004.html

Light from the Heart Nebula

What powers the Heart Nebula? The large emission nebula dubbed IC 1805 looks, in whole, like a human heart. The nebula glows brightly in red light emitted by its most prominent element: hydrogen. The red glow and the larger shape are all created by a small group of stars near the nebula's center. A close up spanning about 30 light years contains many of these stars is shown above . This open cluster of stars contains a few bright stars nearly 50 times the mass of our Sun, many dim stars only a fraction of the mass of our Sun, and an absent microquasar that was expelled millions of years ago. The Heart Nebula is located about 7,500 light years away toward the constellation of Cassiopeia.

http://antwrp.gsfc.nasa.gov/apod/ap061003.html

NASA Observes the Antarctic Ozone Hole

When daylight returns to the South Pole after the total darkness of the polar winter, it sets off a series of chemical reactions that destroy ozone in the stratosphere. As spring progresses in the Southern Hemisphere, NASA satellites observe the resulting development of the Antarctic “ozone hole,” an area of exceptionally low concentrations of stratospheric ozone. The hole begins to develop in mid-August each year and peaks in late September or early October. As summer approaches, weather conditions become less favorable for the ozone-destroying reactions, and the ozone layer stabilizes until the next spring.

This image from September 29, 2006, shows the ozone concentration in the stratosphere above the South Pole observed by the Ozone Monitoring Instrument on NASA’s Aura satellite. Greens and yellows show areas with the highest ozone amounts, while blues and purples show where ozone amounts are lowest. A purple veil of extremely low levels of ozone stretches across most of Antarctica, which is roughly centered in the image.

Scientists generally use Dobson Units to describe ozone concentrations. Ozone in the atmosphere isn’t packed into a single layer at a certain altitude above the Earth’s surface; it’s dispersed. The Dobson Unit describes how much ozone there would be in a column of the atmosphere if all the molecules were squeezed into a single layer. One Dobson Unit is the number of molecules of ozone that would be required to create a layer of pure ozone 0.01 millimeters thick at a temperature of 0 degrees Celsius and a pressure of 1 atmosphere (the air pressure at the surface of the Earth).

The average amount of ozone in the atmosphere is roughly 300 Dobson Units, equivalent to a layer 3 millimeters (0.12 inches) thick—the height of 2 pennies stacked together. Any place where the concentration drops below 220 Dobson Units is considered part of the ozone hole. Average ozone concentrations in the ozone hole are around 100 Dobson Units—about the height of a dime. Stratospheric ozone absorbs ultraviolet (UV) light that can be dangerous to living things. A thinner ozone layer increases humans’ and other creatures’ exposure to harmful UV light.

NASA measurements made by aircraft- and ground-based sensors in the 1980s provided much of our initial understanding of the extent of the ozone hole and its link to the chemicals known as chlorofluorocarbons (CFCs), which human activities were releasing into the atmosphere. In 1987, the Montreal Protocol banned the worst of the ozone-destroying chemicals. Today, NASA scientists are using the latest tools—including satellite observations and computer models of atmospheric chemistry and weather—to determine what effect the ban on CFCs and related chemicals has had and how long we will have to wait for a full ozone layer recovery. NASA shares the latest information and satellite images of the ozone hole with the public on its Ozone Watch Website.

NASA image provided by the Ozone Hole Watch Website.

http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17416

What's Old is New in the Large Magellanic Cloud

This vibrant image from NASA's Spitzer Space Telescope shows the Large Magellanic Cloud, a satellite galaxy to our own Milky Way galaxy. The Large Magellanic Cloud, located 160,000 light-years from Earth, is one of a handful of dwarf galaxies that orbit the Milky Way.

The infrared image offers astronomers a unique chance to study the lifecycle of stars and dust in a single galaxy. Nearly one million objects are revealed for the first time in this Spitzer view, which represents about a 1,000-fold improvement in sensitivity over previous space-based missions. Most of the new objects are dusty stars of various ages populating the Large Magellanic Cloud; the rest are thought to be background galaxies.

The blue color in the picture, seen most prominently in the central bar, represents starlight from older stars. The chaotic, bright regions outside this bar are filled with hot, massive stars buried in thick blankets of dust. The red color around these bright regions is from dust heated by stars, while the red dots scattered throughout the picture are either dusty, old stars or more distant galaxies. The greenish clouds contain cooler interstellar gas and molecular-sized dust grains illuminated by ambient starlight.

Astronomers say this image allows them to quantify the process by which space dust -- the same stuff that makes up planets and even people -- is recycled in a galaxy. The picture shows dust at its three main cosmic hangouts: around the young stars, where it is being consumed (red-tinted, bright clouds); scattered about in the space between stars (greenish clouds); and in expelled shells of material from old stars (randomly-spaced red dots).

http://www.nasa.gov/multimedia/imagegallery/image_feature_666.html

RCW 86: Historical Supernova Remnant

In 185 AD, Chinese astronomers recorded the appearance of a new star in the Nanmen asterism - a part of the sky identified with Alpha and Beta Centauri on modern star charts. The new star was visible for months and is thought to be the earliest recorded supernova. Data from two orbiting X-ray telescopes of the 21st century, XMM-Newton and Chandra, now offer evidence that supernova remnant RCW 86 is indeed the debris from that stellar explosion. Their composite, false-color view of RCW 86 shows the expanding shell of material glowing in x-rays with high, medium, and low energies shown in blue, green, and red hues. Shock velocities measured in the x-ray emitting shell and an estimated radius of about 50 light-years can be used to find the apparent age of the remnant. The results indicate that light from the initial explosion could well have first reached planet Earth in 185 AD. Near the plane of our Milky Way Galaxy, RCW 86 is about 8,200 light-years away.

http://antwrp.gsfc.nasa.gov/apod/ap060928.html

NGC 1499: The California Nebula

What's California doing in space? Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun also lies within the Milky Way's Orion Arm, only about 1,500 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. It glows with the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. In this case, the star most likely providing the energetic starlight is the bright, hot, bluish Xi Persei, just right of the nebula and above picture center. Fittingly, this composite picture was made with images from a telescope in California - the 48-inch (1.2-meter) Samuel Oschin Telescope - taken as a part of the second National Geographic Palomar Observatory Sky Survey.

http://antwrp.gsfc.nasa.gov/apod/ap060924.html

Eris: The Largest Known Dwarf Planet

Is Pluto the largest dwarf planet? No! Currently, the largest known dwarf planet is (136199) Eris, renamed last week from 2003 UB313. Eris is just slightly larger than Pluto, but orbits as far as twice Pluto's distance from the Sun. Eris is shown above in an image taken by a 10-meter Keck Telescope from Hawaii, USA. Like Pluto, Eris has a moon, which has been officially named by the International Astronomical Union as (136199) Eris I (Dysnomia). Dysnomia is visible above just to the right of Eris. Dwarf planets Pluto and Eris are trans-Neptunian objects that orbit in the Kuiper belt of objects past Neptune. Eris was discovered in 2003, and is likely composed of frozen water-ice and methane. Since Pluto's recent demotion by the IAU from planet to dwarf planet status, Pluto has recently also been given a new numeric designation: (134340) Pluto. Currently, the only other officially designated "dwarf planet" is (1) Ceres.

http://antwrp.gsfc.nasa.gov/apod/ap060918.html

11 Hour Star Trails

Fix your camera to a tripod, lock the shutter open, and you can make an image of star trails - graceful concentric arcs traced by the stars as planet Earth rotates on its axis. Of course, the length of the star trails will depend on the exposure time. While exposures lasting just five minutes produce a significant arc, in about 12 hours a given star would trace out half a circle. But in any long exposure, the background glow from light-polluted skies can build up to wash out the trails. Still, astronomer Josch Hambsch produced this stunning composite of star trails around the South Celestial Pole with an effective "all night" exposure time of almost 11 hours. To do it, he combined 128 consecutive five minute long digital exposures recorded in very dark night skies above Namibia. In his final image, the background glow on the right is due in part to the faint, arcing Milky Way.

http://antwrp.gsfc.nasa.gov/apod/ap060915.html

Object Larger than Pluto Named Eris

LOS ANGELES (AP)—A distant, icy rock whose discovery shook up the solar system and led to Pluto's planetary demise has been given a name: Eris.

The christening of Eris, named after the Greek goddess of chaos and strife, was announced by the International Astronomical Union on Wednesday. Weeks earlier, the professional astronomers' group stripped Pluto of its planethood under new controversial guidelines.

Since its discovery last year, Eris, which had been known as 2003 UB313, ignited a debate about what constitutes a planet.

Astronomers were split over how to classify the object because there was no universal definition. Some argued it should be welcomed as the 10th planet since it was larger than Pluto, but others felt Pluto was not a full-fledged planet.

After much bickering, astronomers last month voted to shrink the solar system to eight planets, downgrading Pluto to a "dwarf planet,'' a category that also includes Eris and the asteroid Ceres. The new definition states that dwarf planets are not really planets.

Meanwhile this week, Pluto received a numerical designation to reflect its demotion to dwarf planet status.

Eris' discoverer, Michael Brown of the California Institute of Technology, said the name was an obvious choice, calling it "too perfect to resist.''

In mythology, Eris caused a quarrel among goddesses that sparked the Trojan War. In real life, Eris forced scientists to define a planet that eventually led to Pluto getting the boot. Soon after Pluto's dismissal from the planet club, hundreds of scientists circulated a petition protesting the decision.

Eris' moon also received a formal name: Dysnomia, the daughter of Eris known as the spirit of lawlessness.

Eris, which measures about 70 miles wider than Pluto, is the farthest known object in the solar system at 9 billion miles away from sun. It is also the third brightest object located in the Kuiper belt, a disc of icy debris beyond the orbit of Neptune.

Eris had been without a formal name while astronomers grappled over its status. Brown nicknamed it "Xena'' after the fictional warrior princess pending an official designation. He admits the new name will take some getting used to.

"It's a little sad to see Xena go away,'' he said.

http://www.space.com/scienceastronomy/060914_eris_named.html

M33: Spiral Galaxy in Triangulum

The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy and astronomers in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this detailed, wide field image nicely shows off M33's blue star clusters and pinkish star forming regions which trace the galaxy's loosely wound spiral arms. In fact, the cavernous NGC 604 is the brightest star forming region, seen here at about the 1 o'clock position from the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick for establishing the distance scale of the Universe.

http://antwrp.gsfc.nasa.gov/apod/ap060914.html

Water Worlds: Astronomer Predicts Many Earth-Like Planets

To most common terrestrial dwellers, there's no place like Earth. But new simulations show that many Earth-like planets might exist outside of our solar system.

Through computer simulations scientists examined the formation and evolution of giant planet systems recently detected outside the Earth's solar system. Their results revealed that more than a third of them might contain planets that could potentially support life and could even be covered with deep oceans.

The study focuses on a type of planetary system unlike our solar system that contains gas giants known as "hot Jupiters" orbiting extremely close to their parent stars—even closer than Mercury to our sun, said lead author Sean Raymond, a researcher at the University of Colorado at Boulder.

Migrating giants

Hot Jupiters are giant gas planets, with masses close to or greater than that of Jupiter's, orbiting around stars other than our sun.

These giants are believed to have migrated inward toward their parent stars as the planetary systems were forming, disrupting the space environment and triggering the formation of ocean-covered, Earth-like planets in a "habitable zone" conducive to the formation of life, the scientists reported in the Sept. 8 issue of the journal Science.

Hot Jupiters shift around the rotating disks of dense gas surrounding a newly formed star and fling rocky debris outward where they could merge to form planets like Earth, Raymond said.

At the same time, small icy bodies in the outer reaches of the disk are slowed down and pulled in towards the planets by the violent forces from the surrounding gas. These icy formations deliver water to the planets, which can then host huge oceans, the thinking goes.

New thinking

Scientists had previously thought that as hot Jupiters plowed through the dense gaseous material on their inward migrations toward parent stars, all the surrounding material would be either "vacuumed up" or ejected from the system, Raymondsaid. "The new models indicate these early ideas were probably wrong."

After running simulations, based on theories of how the planets form in our solar system, that lasted more than eight months, Raymond and his team concluded that about one of every three known planetary systems could have evolved as Earth-like planets.

"I think there are definitely habitable planets out there," Raymond said. "But any life on these planets could be very different from ours. There are a lot of evolutionary steps in between the formation of such planets in other systems and the presence of life forms looking back at us."

http://www.space.com/scienceastronomy/060912_earthling_planets.html

Pluto is Now Just a Number: 134340

Pluto has been given a new name to reflect its new status as a dwarf planet.

On Sept. 7, the former 9th planet was assigned the asteroid number 134340 by the Minor Planet Center (MPC), the official organization responsible for collecting data about asteroids and comets in our solar system.

The move reinforces the International Astronomical Union's (IAU) recent decision to strip Pluto of its planethood and places it in the same category as other small solar-system bodies with accurately known orbits.

Pluto's companion satellites, Charon, Nix and Hydra are considered part of the same system and will not be assigned separate asteroid numbers, said MPC director emeritus Brian Marsden. Instead, they will be called 134340 I, II and III, respectively.

There are currently 136,563 asteroid objects recognized by the MPC; 2,224 new objects were added last week, of which Pluto was the first.

Other notable objects to receive asteroid numbers included 2003 UB313, also known as "Xena," and the recently discovered Kuiper Belt objects 2003 EL61 and 2005 FY9. Their asteroid numbers are 136199, 136108 and 136472, respectively.

The MPC also issued a separate announcement stating that the assignment of permanent asteroid numbers to Pluto and other large objects located beyond the orbit of Neptune "does not preclude their having dual designations in possible separate catalogues of such bodies."

Marsden explained that the cryptic wording refers to the future possibility of creating a separate astronomical catalogue specific to dwarf planets. There might even be more than one catalogue created, he said.

The recent IAU decision implies "that there would be two catalogues of dwarf planets—one for just the trans-Neptunian Pluto type and the other for objects like Ceres, which has also been deemed a dwarf planet," Marsden told SPACE.com. "That's why that statement was put there, to reassure people who think there would be other catalogues that this numbering of Pluto doesn't preclude that."

Pluto's asteroid number was first reported today on the website of Sky and Telescope magazine.

http://feeds.feedburner.com/~r/spaceheadlines/~3/21240702/060911_pluto_asteroidnumber.html

Star Clusters Young and Old

Many stars form in clusters. Galactic or open star clusters are relatively young swarms of bright stars born together near the plane of our Milky Way Galaxy. Separated by about a degree on the sky, two nice examples are M46 (upper left) 5,400 light-years in the distance and M47 (lower right) only 1,600 light-years away toward the nautical constellation Puppis. Around 300 million years young M46 contains a few hundred stars in a region about 30 light-years across. Aged 80 million years, M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. But this portrait of stellar youth also contains an ancient interloper. The small, colorful patch of glowing gas in M46 is actually the planetary nebula NGC 2438 - the final phase in the life of a sun-like star billions of years old. NGC 2438 is estimated to be only 3,000 light-years distant and likely represents a foreground object, only by chance appearing along our line of sight to youthful M46.

http://antwrp.gsfc.nasa.gov/apod/ap060910.html

Milky Way: A Crowded Neighborhood

The center of the Milky Way is a crowded neighborhood and not always a calm one, as seen in this image from NASA's Chandra X-ray Observatory. In addition to the supermassive black hole at the center, the area is filled with all sorts of different inhabitants that affect and influence one another.

The image shows three massive star clusters: the Arches (upper right), Quintuplet (upper center), and the GC star cluster (bottom center), which is near the enormous black hole known as Sagittarius A. The massive stars in these clusters can themselves be very bright, point-like X-ray sources, when winds blowing off their surfaces collide with winds from an orbiting companion star. The stars in these clusters also release vast amounts of energy when they reach the ends of their lives and explode as supernovas, which, in turn, heat the material between the stars. The stars near the Galactic Center also can emit X-rays as stellar corpses -- either in the form of neutron stars or black holes in binary systems -- and are also seen as point-like sources in the Chandra image.

http://www.nasa.gov/multimedia/imagegallery/image_feature_649.html

Colorful Moon Mosaic

No single exposure can easily capture faint stars along with the subtle colors of the Moon. But this dramatic composite view highlights both. The mosaic digitally stitches together fifteen carefully exposed high resolution images of a bright, gibbous Moon and a representative background star field. The fascinating color differences along the lunar surface are real, though highly exaggerated, corresponding to regions with different chemical compositions. And while these color differences are not visible to the eye even with a telescope, moon watchers can still see a dramatic lunar presentation tonight. A partial eclipse of the Moon will be visible from Europe, Africa, Asia, and Australia.

http://antwrp.gsfc.nasa.gov/apod/ap060907.html

Drought on the Great Plains

Across the Great Plains of the United States and Canada, devastating drought spread across grasslands and croplands in summer 2006. Poor winter snowfall and a blisteringly hot summer following several years of dry conditions have created a dire situation for many farmers and ranchers across the region. According to a recent article on the New York Times Website, many people are comparing the conditions to the Dust Bowl of the 1930s.

The widespread drought conditions are obvious in this vegetation anomaly image based on data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Places where vegetation is healthier or more abundant than average are green, places where vegetation is about the same as average are pale yellow, and places where vegetation is not as healthy or abundant as average are brown. Gray patches show where no data were available, probably because of persistent clouds. One of the most common satellite-based vegetation maps is a scale, or index, of vegetation greenness called the “NDVI,” short for Normalized Difference Vegetation Index. This image compares NDVI values from July 28-August 12, 2006, to the average values from 2001-2005.

Vegetation was faring worst along the Missouri River through North and South Dakota, but below-average vegetation conditions stretch across parts of Montana, Wyoming, Colorado, northwestern Nebraska, and Minnesota as well. The plains of Canada’s Saskatchewan and Manitoba provinces were suffering drought, too. A few small pockets of green in the image reveal where vegetation greenness values observed by MODIS were higher than average: the mountains of north-central Colorado, southeastern Nebraska, and the Red River Valley. The Red River Valley experienced widespread snowfall and heavy rains in the spring of 2006, leading to significant flooding. The early-season moisture may have helped the vegetation in the area withstand the hot summer. According to the August 29, 2006, update from the U.S. Drought Monitor, most of the Northern Great Plains, as well as much of Oklahoma and Texas, was still in the midst of drought, with many areas falling into the highest category: exceptional drought.

http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17390

Pluto in True Color

Pluto is mostly brown. The above picture captures the true colors of Pluto as well as the highest surface resolution so far recovered. Although no spacecraft has yet visited this distant world, the New Horizons spacecraft launched early this year is expected to reach Pluto in 2015. Pluto recent reclassification, by the International Astronomical Union, from planet to dwarf planet remains a topic of much debate. The above map was created by tracking brightness changes from Earth of Pluto during times when it was being partially eclipsed by its moon Charon. The map therefore shows the hemisphere of Pluto that faces Charon. Pluto's brown color is thought dominated by frozen methane deposits metamorphosed by faint but energetic sunlight. The dark band below Pluto's equator is seen to have rather complex coloring, however, indicating that some unknown mechanisms may have affected Pluto's surface.

http://antwrp.gsfc.nasa.gov/apod/ap060903.html

Barred Spiral Galaxy NGC 1300

Big, beautiful, barred spiral galaxy NGC 1300 lies some 70 million light-years away on the banks of the constellation Eridanus. This Hubble Space Telescope composite view of the gorgeous island universe is one of the largest Hubble images ever made of a complete galaxy. NGC 1300 spans over 100,000 light-years and the Hubble image reveals striking details of the galaxy's dominant central bar and majestic spiral arms. In fact, on close inspection the nucleus of this classic barred spiral itself shows a remarkable region of spiral structure about 3,000 light-years across. Unlike other spiral galaxies, including our own Milky Way, NGC 1300 is not presently known to have a massive central black hole.

http://antwrp.gsfc.nasa.gov/apod/ap060827.html

Ceres: Asteroid or Planet?

Is Ceres an asteroid or a planet? Although a trivial designation to some, the recent suggestion by the Planet Definition Committee of the International Astronomical Union would have Ceres reclassified from asteroid to planet. A change in taxonomy might lead to more notoriety for the frequently overlooked world. Ceres, at about 1000 kilometers across, is the largest object in the main asteroid belt between Mars and Jupiter. Under the newly proposed criteria, Ceres would qualify as a planet because it is nearly spherical and sufficiently distant from other planets. Pictured above is the best picture yet of Ceres, taken by the Hubble Space Telescope as part of a series of exposures ending in 2004 January. Currently, NASA's Dawn mission is scheduled to launch in 2007 June to explore Ceres and Vesta, regardless of their future designations.

http://antwrp.gsfc.nasa.gov/apod/ap060821.html

Eight Planets and New Solar System Designations

How many planets are in the Solar System? This popular question now has a new formal answer according the International Astronomical Union (IAU): eight. Last week, the IAU voted on a new definition for planet and Pluto did not make the cut. Rather, Pluto was re-classified as a dwarf planet and is considered as a prototype for a new category of trans-Neptunian objects. The eight planets now recognized by the IAU are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Solar System objects now classified as dwarf planets are: Ceres, Pluto, and the currently unnamed 2003 UB313. Planets, by the new IAU definition, must be in orbit around the sun, be nearly spherical, and must have cleared the neighborhood around their orbits. The demotion of Pluto to dwarf planet status is a source of continuing dissent and controversy in the astronomical community.

http://antwrp.gsfc.nasa.gov/apod/ap060828.html

Gemini South Star Trails

Stars seem to arc through southern skies in this surrealistic time exposure -- recorded before moonrise from the Gemini South Observatory, Cerro Pachon, Chile, Planet Earth. During the one hour 40 minute exposure camera and tripod were fixed, so the concentric star trails are a reflection of Earth's daily rotation about its axis. The view looks to the south and includes the Gemini telescope enclosure in the foreground. At the apparent center of the curving trails, the South Celestial Pole lies just off the upper left edge. Two faint, wide streaks track the Magellanic Clouds, satellites of the Milky Way Galaxy, while a meteor flashes throught the scene just left of the observatory.

http://antwrp.gsfc.nasa.gov/apod/ap060901.html

Pluto-bound Probe Snaps First Photo

NASA's Pluto-bound New Horizons spacecraft has snapped its first high-resolution photo, an image of distant stars that shows the probe's high-resolution camera works.

This week the Long Range Reconnaissance Imager (LORRI) opened its protective cover and took its first image in space, of Messier 7, a star cluster in our Milky Way galaxy.

The craft's six other primary science instruments have already checked out.

New Horizons launched in January and is due to arrive at Pluto in 2015.

Developed by the Johns Hopkins University Applied Physics Laboratory (APL), which also built and operates the New Horizons spacecraft, LORRI is the long focal length, reflecting telescope on New Horizons, designed to acquire the highest-resolution images of Pluto and its moons during a flyby.

"LORRI is our 'eagle eyes' on New Horizons, providing the most detailed images we have," said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI), Boulder, Colo. "This week's virtuoso first-light performance by LORRI is the best news any Pluto fan could hope for."

"Our hope was that LORRI's first image would prove not only that the cover had opened completely, but that LORRI was capable of providing the required high-resolution imaging of Pluto and Charon," says Andy Cheng, LORRI principal investigator, from APL. "Our hopes were not only met, but exceeded."

Pluto: Down But Maybe Not Out

If you did not like Pluto's demotion, don't give up hope.

Arguments over the newly approved definition for "planet" are likely to continue at least until 2009, and astronomers say there is much that remains to be clarified and refined.

While it is entirely unclear if the definition could ever be altered enough to reinstate Pluto as a planet, astronomers clearly expect some changes.

In a statement today, the largest group of planetary scientists in the world offered lukewarm support for the definition, which was adopted last week by a vote of just a few hundred astronomers at the International Astronomical Union (IAU) General Assembly meeting in Prague.

http://www.space.com/scienceastronomy/060831_planet_definition.html

Oil Spill Near Guimaras Island

Strong winds and high waves capsized a tanker off Guimaras Island in the Philippines on August 11, 2006, spilling more than 200,000 liters of bunker oil into the Panay Gulf, said the Philippines National Disaster Coordinating Council. Long strings and patches of oil still drifted over the water on August 29, 2006, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite captured this image. The oil is grey-white against the mirror-like surface of the water. The bulk of the oil has drifted northeast of the crash site, along the edge of ASTER’s field of view, but long streamer-like tendrils also extend north and west of the ship. Dark patches on the water are cloud shadows or areas of still, smooth water. Land is dark red.

By August 29, the government of the Philippines reported that the oil covered 245 kilometers of coastline, 16 square kilometers of coral reef area, 1,128 hectares of mangrove area, and 1,143 hectares of a marine reserve. At least 17,435 people had been affected by the spill, and many coastal residents were evacuated because of toxic substances on the shore. Even as the Petron Corporation—the ship’s owner—and the Philippine Coast Guard led efforts to clean up the spill, fresh oil was seeping from the sunken tanker on August 29, said the UN Office for the Coordination of Humanitarian Affairs. The tanker had been carrying more than two million liters of oil when it went down.

http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17385

Spirit Beholds Bumpy Boulder

As the Mars Exploration Rover Spirit began collecting images for a 360-degree panorama of new terrain, the rover captured this view of a dark boulder with an interesting surface texture. The boulder is about 40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet) away from Spirit. It is one of many dark, volcanic rock fragments -- many pocked with rounded holes called vesicles -- littering the slope of "Low Ridge." The rock surface facing the rover is similar in appearance to the surface texture on the outside of lava flows on Earth.

Spirit took this false-color image with the panoramic camera on its 810th sol, or Martian day, of exploring Mars (April 13, 2006).

http://www.nasa.gov/multimedia/imagegallery/image_feature_645.html

Stellar Nursery

NASA's Spitzer Space Telescope captured a glowing stellar nursery within a dark globule that reveals the birth of new protostars, or embryonic stars, and young stars never before seen.

The Elephant's Trunk Nebula is an elongated dark globule within the emission nebula IC 1396 in the constellation of Cepheus. Within the globule, a half dozen newly discovered protostars are easily discernible as the bright red-tinted objects, mostly along the southern rim of the globule. These were previously undetected at visible wavelengths due to obscuration by the thick cloud ('globule body') and by dust surrounding the newly forming stars. The newborn stars form in the dense gas because of compression by the wind and radiation from a nearby massive star (located outside the field of view to the left). The winds from this unseen star are also responsible for producing the spectacular filamentary appearance of the globule itself, which resembles that of a flying dragon.

http://www.nasa.gov/multimedia/imagegallery/image_feature_643.html

Storm Clouds Brewing

This mass of storm clouds was observed by Expedition 1 from the International Space Station. The picture was the first Earth observation still image downlinked by the three-man crew, which consisted of flight engineer Sergei Krikalev, Soyuz commander Yuri Gidzenko and mission commander William Shepherd.

Currently, additional imagery taken by Expedition 13 crew members Jeffrey Williams, Pavel Vinogradov and Thomas Reiter has brought the total number of images of Earth taken from station to more than 248,000.

http://www.nasa.gov/multimedia/imagegallery/image_feature_640.html

The Face of Phoebe

Phoebe's true nature is revealed in startling clarity in this mosaic of two images taken during Cassini's flyby on June 11, 2004. This image of Saturn’s moon shows evidence for the emerging view that Phoebe may be an ice-rich body coated with a thin layer of dark material. Small bright craters in the image are probably fairly young features. This phenomenon has been observed on other icy satellites, such as Jupiter’s Ganymede.

When impactors slammed into the surface of Phoebe, the collisions excavated fresh, bright material -- probably ice -- underlying the surface layer. Further evidence for this can be seen on some crater walls where the darker material appears to have slid downwards, exposing more light-colored material. Some areas of the image that are particularly bright -- especially near lower right -- are over-exposed.

http://www.nasa.gov/multimedia/imagegallery/image_feature_639.html

Moon Framed

Earth and its Moon are nicely framed in this image taken from the aft windows of the Space Shuttle Discovery in 1998. Discovery - on mission STS-95 - was flying over the Atlantic Ocean at the time this image was taken. The STS-95 mission also marked the return of pioneering Mercury astronaut and U.S. Senator John Glenn to space.

http://www.nasa.gov/multimedia/imagegallery/image_feature_638.html

Missing Gas Found in Milky Way

The true abundance in the Milky Way of a heavy, primordial form of hydrogen has eluded scientists for decades, but it turns out that huge quantities of it have been hidden in the dust that is scattered between stars.

The new finding relied on satellite measurements of a type of hydrogen called deuterium and found that its distribution in our galaxy is patchy rather than uniform. It will force big changes in theories about star and galaxy formation, astronomers say.

"Since the 1970s we have been unable to explain why deuterium levels vary all over the place," said Jeffrey Linsky, an astrophysicist at the University of Colorado at Boulder. "The answer we found is as unsettling as it is exciting."

For More Info: http://www.space.com/scienceastronomy/060821_mystery_monday.html

The Plane of the Ecliptic

The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left) the Moon lit by Earthshine, the sun's corona rising over the Moon's dark limb and the planets Saturn, Mars and Mercury.

The ecliptic plane is defined as the imaginary plane containing the Earth's orbit around the sun. In the course of a year, the sun's apparent path through the sky lies in this plane. The planetary bodies of our solar system all tend to lie near this plane, since they were formed from the sun's spinning, flattened, proto-planetary disk.

This image captures a momentary line-up looking out along this fundamental plane of our solar system.

http://www.nasa.gov/multimedia/imagegallery/image_feature_635.html

Flaming Star

This is a false-color image of the star AE Aurigae (bright source of light near the center of image) embedded in a region of space containing smoke-like filaments of carbon-rich dust grains. Such dust might be hiding deuterium, an isotope of hydrogen, and stymieing astronomers' efforts to study star and galaxy formation. NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite has surveyed the local deuterium concentration in the galaxy and found far more than expected. Because deuterium is a tracer of star and galaxy evolution, this discovery has the potential to radically alter theories about how stars and galaxies form.

http://www.nasa.gov/multimedia/imagegallery/image_feature_634.html

Nukuoro Atoll

Located just north of the equator (3.85° North, 154.9° East), this classically shaped atoll is part of the Caroline Islands, which stretch northeast of Papua New Guinea in the western Pacific. (The islands are roughly north of Guadalcanal, and southeast of the Guam and Truk Islands.) Nukuoro Atoll is one of 607 islands that make up the Federated States of Micronesia, a United Nations Trust Territory under U.S. administration.

An atoll is a type of low, coral island found in tropical oceans and consisting of a coral-algal reef surrounding a central depression. The depression may be part of the emergent island, but more typically is a part of the sea (that is, a lagoon).

About 900 people live on Nukuoro, whose lagoon is 6 kilometers (about 3.7 miles) in diameter. Fishing, animal husbandry and agriculture (taro and copra) are the main occupations. Nukuoro is remote and has no airstrip; a passenger boat calls irregularly only once a month. The tiny population speaks its own unique language.

This image was taken by the Expedition 13 crew aboard the International Space Station on May 31, 2006.

http://www.nasa.gov/multimedia/imagegallery/image_feature_632.html

Interstellar Envelope

This gold aluminum cover was designed to protect the Voyager 1 and 2 "Sounds of Earth" gold-plated records from micrometeorite bombardment, but also serves a double purpose in providing the finder a key to playing the record. The explanatory diagram appears on both the inner and outer surfaces of the cover, as the outer diagram will be eroded in time.

Flying aboard Voyagers 1 and 2 are identical records, carrying the story of Earth far into deep space. The 12-inch gold-plated copper discs contain greetings in 60 languages, samples of music from different cultures and eras and natural and man-made sounds from Earth. They also contain electronic information that an advanced technological civilization could convert into diagrams and images.

http://www.nasa.gov/multimedia/imagegallery/image_feature_631.html

Death Valley National Park

At 86 meters (282 feet) below sea level, Death Valley, California, is one of the hottest, driest places on the planet. On average, the area sees only about 5 centimeters (1.96 inches) of rain a year, and summer temperatures routinely soar above 38 degrees Celsius (100 degrees Fahrenheit). At night, temperatures drop considerably, and many animals in Death Valley are nocturnal as a result. Plants and animals living in this punishing environment have had to adapt to extremes of temperature and aridity.

This image is compiled from observations by the Enhanced Thematic Mapper Plus sensor on the Landsat 7 satellite on June 11 and July 20, 2000. In this image, green indicates vegetation, which increases with altitude. The peaks of Death Valley National Park sport forests of juniper and pine. The dots of brilliant green near the right edge of the image fall outside park boundaries, and probably result from irrigation. On the floor of the valley, vegetation is sparse, yet more than 1,000 different species eke out an existence in the park, some of them sending roots many feet below ground. The varying shades of brown, beige and rust indicate bare ground; the different colors result from varying mineral compositions in the rocks and dirt. Although they appear to be pools of water, the bright blue-green patches in the scene are actually salt pans that hold only a little moisture.

http://www.nasa.gov/multimedia/imagegallery/image_feature_630.html

Stellar Quakes

In December 2004, a neutron star flared up so brightly, it temporarily blinded all the x-ray satellites in space, and lit up the Earth's upper atmosphere. This tremendous blast of energy was from a giant flare created by the neutron star's twisting magnetic field. Objects like this are called magnetars, and they produce magnetic fields trillions of time more powerful than those here on Earth. These fields are so strong they can actually buckle the surface of the neutron star causing these powerful star quakes.

http://www.nasa.gov/multimedia/imagegallery/image_feature_626.html