Search the Community

The good people working with the Spitzer space telescope have made a huge discovery. Spitzer sees in a number of bands of the infrared spectra some of which have never been possible to explore before. Our atmosphere absorbs a large chunk of the infrared spectra- specifically microwaves. Spitzers position high above our atmosphere allows it to see and explore things that human eyes simply can not and have only now begun to have the ability to explore. Our understanding of our own home galaxy is tenuous at best. From inside the galaxy, it is difficult to tell the shape and for of the galaxy as it would appear from the outside. We've known for some time that our galaxy is a spiral. We can see the spiral arms with optical astronomy. For many years when astronomers have looked for a model of our galaxy, they would very likely cite M31 or the Andromeda galaxy. Andromeda is a big, well behaved spiral galaxy relatively close and easily observable from earth. The discovery that is probably going to boot Andromeda's place in the textbooks is the Milky Way's Bar. A galactic bar is a feature found in young spiral galaxies and is thought to be caused by instability caused by uneven mass distribution. As a barred spiral ages, this feature slowly disappears and the spiral begings to look more like our old friend the Andromeda galaxy. This is our new vision of the galaxy and our new found bar. So what is our new galactic model? Here's NGC 1300 which will probably replace Andromeda as the galaxy that most looks like the Milky Way as we now understand it.

Climate change is very real and it has been going on in cycles since the planet formed. Three Orbital cycles that affect climate: Orbital Eccentricity: 100,000 year Cycle Orbital Tilt: 42,000 year cycle Orbital Wobble: 25,800 year cycle Orbital Eccentricity: the earth's orbit around the sun forms an ellipse. Every 100,000 years or so the ellipse "flops" into a pattern that changes solar exposure. This trend is working is way to a peak this century. Orbital Tilt: The tilt of the equator varies between 21.6 to 24.5 degrees. This cycle is right in the middle. Orbital Wobble: The earths axis of rotation "wobbles" in a circular pattern over the period of the cycle which is approaching maximum. Catastrophic climate change Over the course of the planets geological record, it is apparent that there have been a number of catastrophic events that have caused either short or long term variations in the climate. These events are: Comet Impacts Asteroid Impacts Super-Volcanic Eruption/Out-gassing Comet Impacts: have taken place with regularity over geological time. One theory of the origin of our atmosphere is that water and gases locked up in comets seeded our atmosphere. Other theories are that comets delived the seeds of life to our planet in the very distant past. While they have had beneficial side effects in the past, comets are unbelievably destructive. Comets are gas and ice and have a nasty tendency to explode when heated by the atmosphere creating a huge fireball airburst of thousands of megatons of energy: enough energy to completely destroy a continent and wreak the climate for decades in a condition not unlike nuclear winter. Are you ready for the good part? This has happened several times in our planets history: most recently the Tunguska comet impact of 1908. Asteroid Impacts: the bad news of comet impacts is even worse for asteroids: they are solid and survive the atmosphere. They strike the surface and vaporize rock/soil and hurl molten material for hundreds of miles in all directions. The fireball itself is very much like a huge nuclear explosion which puts tremendous amounts of super-heated ash and dust into the upper atmosphere. This causes a decades long "nuclear winter" which changes the entire ecosystems. It is believed that this is what caused the mass extinctions that ended the Permian and Cretacous eras (AKA KT extinction). Super-Volcanic Eruption/Out-gassing: from time to time there have been extremely massive volcanic eruptions and periods of volcanic hyper-activity that have been so violent and have released so much CO2 and SO4 that they have simply poisioned massive land areas. I'm not describing the eruption of a Mount St. Helens or even a Krakatau, which both influenced the global climate, but entire regions erupting at once. One of the great extinction events of the past was thought to have been caused when hundreds of volcanoes, rifts and magma flows formed Siberia.

The Milky Way is twice the size we thought it was University of Sydney 20 February 2008 Source Link We were tossing around ideas about the size of the Galaxy, and thought we had better check the standard numbers that everyone uses," Professor Gaensler said. Image credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA) It took just a couple of hours using data available on the internet for University of Sydney scientists to discover that the Milky Way is twice as wide as previously thought. Astrophysicist Professor Bryan Gaensler led a team that has found that our galaxy - a flattened spiral about 100,000 light years across - is 12,000 light years thick, not the 6,000 light years that had been previously thought. Proving not all science requires big, expensive apparatus, Professor Gaensler and colleagues, Dr Greg Madsen, Dr Shami Chatterjee and PhD student Ann Mao, downloaded data from the internet and analysed it in a spreadsheet. "We were tossing around ideas about the size of the Galaxy, and thought we had better check the standard numbers that everyone uses. It took us just a few hours to calculate this for ourselves. We thought we had to be wrong, so we checked and rechecked and couldn't find any mistakes." The University of Sydney team's analysis differs from previous calculations because they were more discerning with their data selection. "We used data from pulsars: stars that flash with a regular pulse," Professor Gaensler explains. "As light from these pulsars travels to us, it interacts with electrons scattered between the stars (the Warm Ionised Medium, or WIM), which slows the light down. "In particular, the longer (redder) wavelengths of the pulse slow down more than the shorter (bluer) wavelengths, so by seeing how far the red lags behind the blue we can calculate how much WIM the pulse has travelled through. "If you know the distance to the pulsar accurately, then you can work out how dense the WIM is and where it stops - in other words where the Galaxy's edge is. "Of the thousands of pulsars known in and around our Galaxy, only about 60 have really well known distances. But to measure the thickness of the Milky Way we need to focus only on those that are sitting above or below the main part of the Galaxy; it turns out that pulsars embedded in the main disk of the Milky Way don't give us useful information." Choosing only the pulsars well above or below us cuts the number of measurements by a factor of three, but it is precisely this rejection of data points that makes The University of Sydney's analysis different from previous work. "Some colleagues have come up to me and have said 'That wrecks everything!'" says Professor Gaensler. "And others have said 'Ah! Now everything fits together!'" The team's results were presented in January this year at the 211th meeting of the American Astronomical Society in Austin, Texas. About Professor Bryan Gaensler: Professor Gaensler is a graduate of the University of Sydney and a former Young Australian of the Year. After working at the Department of Astronomy at Harvard University he was lured back to Australia on prestigious Federation Fellowship. One of the world's leading astronomers, his research interests include studying the essential role that magnetic fields play in the generation of turbulence and large-scale structures, the production of high-energy cosmic ray particles, and the formation of the first stars and galaxies.

Here is Messenger's first look at Mercury: the first pictures since Mariner 10 made three fly bys in 1974 and 1975. It is believed that Mercury's surface has been largely undisturbed since the Solar Systems late bombardment phase ~4-5 billion years ago. Over the next few months Messenger will settle in to an orbit of Mercury and will stay there for extended studies of the planet.

NASA's Messenger (MErcury Surface, Space ENvironment, GEochemistry and Ranging) probe made its first fly-by of Mercury today and over the next few months will settle into orbit for an extended study of the planet. Messenger is the first probe to visit Mercury since Mariner 10 back in 1975. Because of its position in the solar system, Mercury is very unique planet. Constantly seared by heat and radiation from the sun, the chemistry of Mercury has been skewed. All of the volitile elements like oxygen, hydrogen have been cooked away. The ordinary compounds like silicates and oxides can't form causing a very different high energy chemistry. All that is left of Mercury over the eons is a cinder of heavy elements and minerals formed at very high temperatures. Of all the planets, Mercury is 2nd in density only to the earth. It has no atmosphere but alpha particles (helium nuclei) are easily detected. This is a marker of radioactive decay from heavy elements like uranium or thorium or radioactive isotopes of less exotic elements. If we could ever figure out how to mine Mercury, it would probably be a mineralogical treasure house. Mercury is heavily cratered and sports a giant crater that covers almost 1/3 of the planet and nearly blew the planet apart. In the days to come we should see some cool photos of the roasted planet.

V1280 Scorpii = Nova Scorpii 2007 (February 7, 2007) Source: American Association of Variable Star Observers IAUC 8803 announces a new nova in Scorpius, independently discovered by Y. Nakamura and Y. Sakurai. The position is 16:57:40.91 -32:20:36.4 J2000 and the unfiltered magnitude is about 8.3 (T. Krajci, 2007-02-06). Spectra indicate blue color, no emission blueward of 540nm, but Halpha emission with P-Cyg profile. Report observations to the AAVSO as: 9999+99 V1280 Sco. Please be sure to indicate what you used for comparison stars. Thank you for your astronomical efforts and contributions! This special notice was compiled by: Arne A. Henden _________________________________________________________________ No- this isn't a super-nova. They are bigger and more dramatic. This is an outburst of a recurrent nova- a white dwarf that has an extremely unstable outer layer. Here is a good explanation of how they tick: Nova at Wiki This Nova is special because it is the brightest one in several years and is fairly easy to see. If you go outside to look for it, it is the "new" star inside the curl in Scorpio's tail.

Ooops, wrong hobbits. New 'Hobbit' Galaxies Discovered Around Milky Way By Ker Than, Staff Writer for Space.com January 15, 2007 Source Link Researchers from the Sloan Digital Sky Survey (SDSS-II) announced the discovery of eight new dwarf galaxies, seven of them satellites orbiting the Milky Way. They resemble systems cannibalized by the Milky Way billions of years ago and help close the gap between the observed number of dwarf satellites and theoretical predictions. Credit: Vasily Belokurov, SDSS-II, Astronomy magazine, Kalmbach Publishing Co. A recent sky survey has turned up eight new members in our Local Group of galaxies, including a new class of ultra-faint "hobbit" galaxies and what might be the smallest galaxy ever discovered. The Local Group is a collection of about 40 galaxies, of which the Milky Way and Andromeda are the dominant members. The rest of the galaxies are mostly small satellites known as

VLT Image of Starburst Galaxy NGC 1313 ESO Press Release November 23, 2006 Source Link The central parts of the starburst galaxy NGC 1313. The very active state of this galaxy is very evident from the image, showing many star formation regions. A great number of supershell nebulae, that is, cocoon of gas inflated and etched by successive bursts of star formation, are visible. The green nebulosities are region emitting in the ionised oxygen lines and may harbour clusters with very hot stars. This colour-composite is based on images obtained with the FORS1 instrument on one of the 8.2-m Unit Telescope of ESO's Very Large Telescope, located at Cerro Paranal. The data were obtained in the night of 16 December 2003, through different broad- (R, B, and z) and narrow-band filters (H-alpha, OI, and OIII). The data were extracted from the ESO Science Archive and fully processed by Henri Boffin (ESO). The captivating appearance of this image of the starburst galaxy NGC 1313, taken with the FORS instrument at ESO's Very Large Telescope, belies its inner turmoil. The dense clustering of bright stars and gas in its arms, a sign of an ongoing boom of star births, shows a mere glimpse of the rough times it has seen. Probing ever deeper into the heart of the galaxy, astronomers have revealed many enigmas that continue to defy our understanding. This FORS image of the central parts of NGC 1313 shows a stunning natural beauty. The galaxy bears some resemblance to some of the Milky Way's closest neighbours, the Magellanic Clouds. NGC 1313 has a barred spiral shape, with the arms emanating outwards in a loose twist from the ends of the bar. The galaxy lies just 15 million light-years away from the Milky Way - a mere skip on cosmological scales. The spiral arms are a hotbed of star-forming activity, with numerous young clusters of hot stars being born continuously at a staggering rate out of the dense clouds of gas and dust. Their light blasts through the surrounding gas, creating an intricately beautiful pattern of light and dark nebulosity. But NGC 1313 is not just a pretty picture. A mere scratch beneath the elegant surface reveals evidence of some of the most puzzling problems facing astronomers in the science of stars and galaxies. Starburst galaxies are fascinating objects to study in their own right; in neighbouring galaxies, around one quarter of all massive stars are born in these powerful engines, at rates up to a thousand times higher than in our own Milky Way Galaxy. In the majority of starbursts the upsurge in star's births is triggered when two galaxies merge, or come too close to each other. The mutual attraction between the galaxies causes immense turmoil in the gas and dust, causing the sudden 'burst' in star formation. Larger region of the sky around the starburst galaxy NGC 1313 showing the larger scale disturbance of the galaxy. The galaxy shows some large deformations in the lower right part of the image, while diffuse matter is also present at the top of the image. All this signals a very tormented past which could be at the origin of the burst of star formation. The image was made from data from the Digitized Sky Survey, obtained through blue, red and infrared filters. The "Second Epoch Survey" of the southern sky was made by the Anglo-Australian Observatory (AAO) with the UK Schmidt Telescope. Plates from this survey have been digitized and compressed by the ST ScI. The data were extracted and colour-composed by Henri Boffin (ESO). NGC 1313's appearance suggests it has seen troubled times: its spiral arms look lop-sided and gas globules are spread out widely around them. This is more easily seen in ESO 43b/06, showing a larger area of the sky around the galaxy. Moreover, observations with ESO's 3.6-m telescope at La Silla have revealed that its 'real' centre, around which it rotates, does not coincide with the central bar. Its rotation is therefore also off kilter. Strangely enough NGC 1313 seems to be an isolated galaxy. It is not part of a group and has no neighbour, and it is not clear whether it may have swallowed a small companion in its past. So what caused its asymmetry and stellar baby boom? An explanation based on the presence of the central bar also does not hold for NGC 1313: the majority of its star formation is actually taking place not in its bar but in dense gassy regions scattered around the arms. By what mechanism the gas is compressed for stars to form at this staggering rate, astronomers simply aren't sure. Probing further into NGC 1313's insides reveals yet more mysteries. In the midst of the cosmic violence of the starburst regions lie two objects that emit large amounts of highly energetic X-rays - so-called ultra-luminous X-ray sources (ULX). Astronomers suspect that they might be black holes with masses of perhaps a few hundred times the mass of our Sun each, that formed as part of a binary star system. How such objects are created out of ordinary stars cannot be conclusively explained by current models. NGC 1313 is an altogether very intriguing target for astronomy. This image, obtained with ESO's Very Large Telescope, demonstrates once again how the imager FORS is ideally suited to capturing the beauty and stunning complexity of galaxies by observing them in different wavelength filters, combined here to form a stunning colour image. >>A high resolution image (with zoom-in possibilities) and its caption is available on this page. Follow the source link back and you'll find wallpaper images. Technical Information: ESO PR Photo 43a/06 is a colour-composite based on images obtained with the FORS1 instrument on one of the 8.2-m Unit Telescope of ESO's Very Large Telescope, located at Cerro Paranal. The data were obtained in the night of 16 December 2003, through different broad- (R, B, and z) and narrow-band filters (H-alpha, OI, and OIII). The data were extracted from the ESO Science Archive and fully processed by Henri Boffin (ESO). ESO PR Photo 43b/06 is made from images from the Digital Sky Survey, obtained through blue, red and infrared filters. The data was extracted and colour-composed by Henri Boffin (ESO).

Two supernovae (circled) on either side of galaxy NGC 1316's bright core resemble eyes and a nose in this visible-light image from NASA's Swift satellite. Another bright spot at far left is a star in our own galaxy (Image: NASA/Swift/S Immler) Supernovae explode in rare double-whammy November 20, 2006 NewScientist.com news service A portrait of two supernovae that exploded just five months apart in the same galaxy has been made by NASA's Swift telescope. The galaxy, called NGC 1316, has now produced four supernovae in 26 years, the highest rate ever measured. All four supernovae were of type Ia, which are thought to occur when a stellar ember called a white dwarf collects too much matter from a companion star, igniting a runaway nuclear reaction that tears the white dwarf apart. The supernovae were both initially detected from the ground by an amateur astronomer in South Africa named Berto Monard. Swift was then called upon to make observations at ultraviolet and X-ray wavelengths. The first event was detected on 19 June 2006 and appears as a yellowish spot on the right. The second event was detected on 5 November, and appears as another spot at mid-left. Delayed reaction The white patch between the two supernovae is the galaxy's bright core. The spot at far left is a star in our own galaxy that happens to lie in the same direction as NGC 1316. The two supernovae add to two previous ones in the same galaxy, also of type Ia, that appeared in 1980 and 1981. This is the highest rate of supernovae of any kind ever recorded for a single galaxy. A typical large galaxy has around three supernovae per century. The host for these supernovae is a massive elliptical galaxy about 80 million light years away that appears to have merged with a spiral galaxy within the past 2 billion years. It is possible that the high rate of supernovae is a sort of delayed reaction to the merger, says Peter Brown of Pennsylvania State University in State College, US, a member of the team that made the Swift observations. Stellar baby boom Mergers tend to trigger high rates of star formation, and after a couple of billion years of stellar evolution, this could lead to higher rates of type Ia supernovae, he says. "If you have more stars being born, then you will have more that will die," he told New Scientist. But he says that it could also be a statistical fluke. A large number of galaxies are being monitored for supernovae, and every once in a while one would expect to observe a series like this in a single galaxy just by chance, he says. In addition to monitoring the sky for gamma-ray bursts

Moon

World-class radio telescopes face closure November 4, 2006 Jeff Hecht for NewScientist.com news service Source Link Two of the world's best-known radio observatories

Hubble mission will be devilishly complex Kelly Young for NewScientist.com news service 01 November 2006 Source Link The space shuttle's final flight to upgrade the Hubble Space Telescope will be one of its most complex yet, featuring five spacewalks and some quick bolt changes usually reserved for the pit stops of car races. On Tuesday, NASA announced to great fanfare that it would send a shuttle to service Hubble as early as May 2008. If the mission were successful, Hubble would have six working instruments for the first time since 1993 and would be able to do science until at least 2013, adding about five years to its professional lifetime. "Looking back on the last four years, without reservation, today is my happiest day to be at the office," said Preston Burch, Hubble's mission manager at NASA's Goddard Space Flight Center in Greenbelt, Maryland, US. The mission had been cancelled in 2004 because of safety risks to the shuttle crew

Discovery of Gamma Rays from the Edge of a Black Hole Press Release of the Max Planck Society Oct 26, 2006 Source Link H.E.S.S. discovers drastic variations of very-high-energy gamma rays from the central engine of the giant elliptical galaxy M 87 The astrophysicists of the international H.E.S.S. collaboration report the discovery of fast variability in very-high-energy (VHE) gamma rays from the giant elliptical galaxy M 87. The detection of these gamma-ray photons - with energies more than a million million times the energy of visible light - from one of the most famous extragalactic objects on the sky is remarkable, though long-expected given the many potential sites of particle acceleration (and thus gamma-ray production) within M 87. Much more surprising was the discovery of drastic gamma-ray flux variations on time-scales of days. These results, for the first time, exclude all possible options for sites of gamma-ray production, except for the most exciting and extraordinary one: the immediate vicinity of the super-massive black hole which is located in the centre of M 87 (Science Express, October 26, 2006). Fig. 1: Image of radio galaxy M 87 seen in visible light. The central region, from which the VHE gamma rays are seen, is located in the upper left part of the image and the relativistic plasma jet extends to the bottom right.(HST) An international team of astrophysicists from the H.E.S.S. collaboration has announced the discovery of short-term variability in the flux of very-high-energy (VHE) gamma rays from the radio galaxy M 87. In Namibia, the collaboration has built and operates a detection system, known as Cherenkov telescopes, which permits these gamma rays to be detected from ground level (see notes). Pointing this system at a nearby galaxy, M 87, the team has detected VHE gamma rays over the past four years. The real surprise is, however, that the intensity of the emission can be seen to change drastically within a few days on occasion. The giant radio galaxy M 87 [editor's note: this is a reference image of M87 from my own files.] This galaxy, located 50 million light-years away in the constellation Virgo, harbours a super-massive black hole of 3 thousand million solar masses from which a jet of particles and magnetic fields emanates. However, unlike for previously-observed extragalactic sources of VHE gamma rays - known as Blazars - the jet in M 87 is not pointing towards the Earth but is seen at an angle of about 30

Wow! Striking Green Comet Suddenly Visible in Evening Sky Robert Roy Britt Senior Science Writer for Space.com October 26, 2006 Source Link Tony Wilder of Chippewa Falls, Wisconsin photographed comet Swan amid city glow this week. A faint meteor was captured streaking across the right side of the image, too. Credit: Tony Wilder What had been a modest comet seen only with binoculars or telescopes flared up this week to become visible to the naked eye. Comet Swan, as it is called, is in the western sky after sunset from the Northern Hemisphere. It remains faint, likely not easy to find under bright city lights but pretty simple to spot from the countryside. It is a "fairly easy naked-eye comet," said Pete Lawrence, who photographed the comet from the UK. "The tail is now showing some interesting features too." Find it The comet, also catalogued as C/2006 M4, is about halfway up in the sky in the direction of the constellation Corona Borealis. As with most comets, this one looks like a fuzzy star. It has an interesting green tint, however, indicating it has a lot of the poisonous gas cyanogen and diatomic carbon, astronomers say. Sam Storch, a long-time sky watcher from Long Island, NY, said the comet appears "quite a bit deeper than any other green I have seen in any sky object, even planetary nebulae." "Comet Swan is very easy to find," said Joe Rao, SPACE.com's Skywatching Columnist. "In good binoculars it appears as a bright, symmetrical and surprisingly green blob." Legendary objects Comets, the stuff of legend and myth, are frozen leftovers of the solar system's formation. Most orbit the Sun out beyond Neptune, but a few wander through the inner solar system now and then. As a comet gets closer to the Sun, solar radiation boils the frozen gases, along with dust, off the comet's surface. Sunlight reflects off this material, creating a head, or coma. Some comets never get very bright. Others brighten dramatically. Some even come unglued as they round the Sun. Some comets, like Swan, also sport a tail or two. Such detail is best seen with binoculars or a small telescope. Comet Swan was discovered last year. It makes its closest approach to Earth today. Eventually it will return to the distant reaches of the solar system.

This is a deep field image of the Orion nebulea (M42). It's the little glowy patch that you see along Orion's belt on winter nights. If you look closely at the left hand side, you can see the tiny Horse-head nebulea which is a region of dark gas back lite by the bright reflection nebulea. Orion is an area of intense study. This is a stellar nursery that is home to many infant stars- t-tauri variables and ZAMS (Zero-Aged Main Sequence stars). The luminosity of young O and B embedded within the nebulea powers this magnificant light show. This and other spectacular images can be had from Astronomy Picture of the Day. There is a plugin for APOD on goole desktop or google homepage. I think there is one for Firefox as well. If that's not the cool wallpaper, I don't know what would be.

Jupiter's Little Red Spot Growing Stronger Press Release: 10.10.06 Nasa- Goddard Space Flight Center Source Link These are two views of Jupiter's Little Red Spot taken with the Hubble Space Telescope in April 2006. The left image is a close-up view. In the right image, a box has been added to show the Little Red Spot's location on Jupiter. The larger Great Red Spot, which has been observed for the past 400 years, can be seen to the right. Image Credit: NASA / ESA / Amy Simon-Miller ______________________________________________________ The highest wind speeds in Jupiter's Little Red Spot have increased and are now equal to those in its older and larger sibling, the Great Red Spot, according to observations with NASA's Hubble Space Telescope. The Little Red Spot's winds, now raging up to approximately 400 miles per hour, signal that the storm is growing stronger, according to the NASA-led team that made the Hubble observations. The increased intensity of the storm probably caused it to change color from its original white in late 2005, according to the team. "No one has ever seen a storm on Jupiter grow stronger and turn red before," said Amy Simon-Miller of NASA's Goddard Space Flight Center, Greenbelt, Md., lead author of a paper describing the new observations appearing in the journal Icarus. "We hope continued observations of the Little Red Spot will shed light on the many mysteries of the Great Red Spot, including the composition of its clouds and the chemistry that gives it its red color." Although it seems small when viewed against Jupiter's vast scale, the Little Red Spot is actually about the size of Earth, and the Great Red Spot is around three Earth diameters across. Both are giant storms in Jupiter's southern hemisphere powered by warm air rising in their centers. The Little Red Spot is the only survivor among three white-colored storms that merged together. In the 1940s, the three storms were seen forming in a band slightly below the Great Red Spot. In 1998, two of the storms merged into one, which then merged with the third storm in 2000. In 2005, amateur astronomers noticed that this remaining, larger storm was changing color, and it became known as the Little Red Spot after becoming noticeably red in early 2006. The new Hubble observations by the team reveal that winds in the Little Red Spot have grown stronger compared to previous observations. In 1979, Voyager 1 and 2 flew by Jupiter and recorded that top winds were only about 268 miles per hour in one of the "parent" storms that merged to become the Little Red Spot. Nearly 20 years later, the Galileo orbiter revealed that top wind speeds were still the same in the parent storm, but winds in the Great Red Spot blew at up to 400 miles per hour. The team used Hubble's new Advanced Camera for Surveys instrument to discover that top wind speeds in both storms are now the same, because this instrument has enough resolution to track small features in these storms, revealing their wind speeds. Scientists are not sure why the Little Red Spot is growing stronger. One possibility is a change in size. These storms naturally fluctuate in size, and their winds spin around their central core of rising air. If the storm were to become smaller, its spiraling winds would increase the same way spinning ice skaters turn faster by pulling their arms closer to their bodies. Another possibility is that it's the only survivor. "The lack of other large storms in the same latitude on Jupiter leaves more energy to feed the Little Red Spot," said Simon-Miller. According to the team, the increased intensity of the Little Red Spot probably explains why it changed color. It is likely to be behaving like the Great Red Spot for two reasons: it has the same wind speed and the team's color analysis showed that it really is the same color as the Great Red Spot. It's probably pulling up gaseous material from far below that changes color when exposed to ultraviolet radiation in sunlight. The question remains whether the storm is pulling up something that it wasn't before, because its increased intensity allows it to reach deeper, or whether it is pulling up the same material but the higher winds allow the storm to hold it aloft longer, increasing the time it is exposed to solar ultraviolet light and turning it red. The team could confirm exactly what the red material is if they are able to use a technique called spectroscopy in future observations of the Little Red Spot. Spectroscopy is an analysis of the light given off by an object. Each element and chemical gives a unique signal - brightness at specific colors or wavelengths. Identifying these signals reveals an object's composition. However, spectroscopy of Jupiter's atmosphere is complicated because it has many chemicals that could turn red if exposed to ultraviolet light. "We need to simulate different possible Jupiter atmospheres in a lab so we can discover what spectrometric signals they give. We will then have something to compare with the actual spectrometric signal," said Simon-Miller. The team includes Simon-Miller, Dr. Nancy J. Chanover and Michael Sussman of New Mexico State University, Las Cruces, N.M.; Dr. Glenn S. Orton of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Irene G. Tsavaris of the University of Maryland, College Park; and Dr. Erich Karkoschka of the University of Arizona, Tucson ------------------------------------------------------------------------------------ The red spots of Jupiter have been described as a shere between fronts with differential temperatures, a hurricane and a magnetic storm. Truthfully, it has never really been adaquately explained or modeled. The great red spot has been around for at least 400 years. "Red jr" as it is nicknamed has formed in recent years. One of the biggest mysteries of star formation is how and when do proto-stars pass through the barrier and become stars. For large stars, the ignition of the Hydrogen burning fusion process is easily explained by pressure and heat created by gravity. However in very small stars, this trigger-point and how it is reached is not at all obvious. Jupiter is often called a "failed star" because it is mostly hydrogen and helium gas. It is the prototypical "brown dwarf". In fact extra-solar planets are described in terms of Jupiters mass. Since the Pioneer, Voyager and Gallieo probes have visited Jupiter, we've been very surprised by how energetic and active a cold gas giant can be. With the exception of the Sun, it has the most powerful magnetic and gravitational fields in the solar system. In this photo of Jupiters northern polar region taken by the Galieo probe, we see massive aurora activity in which charged solar plasmas interact with Jupiters magnetic field. Any manned mission to Jupiters moons would have to contend with intense radiation. Jupiter shows us tantalizing clues of processes and forces that we are only beginning to understand. What role does magnetism play? How do magnetic and gravitational fields interact and how much of that energy is bound into the system? So how do dwarf main sequence stars fire up? Perhaps Jupiter will show us one day.

Hubble's main camera hobbles back to life October 2, 2006 David Shiga for NewScientist.com Source Link Hubble's most frequently used instrument, the Advanced Camera for Surveys (ACS), is partially functioning again, after shutting down unexpectedly last week. Before it shut down on 23 September, the ACS was Hubble's most frequently used instrument. It uses three channels that are essentially three different cameras, and the problem began shortly after Hubble's managers attempted to switch power from the Solar Blind Channel (SBC) to the High Resolution Channel (HRC). Despite the command to switch, Hubble's computer detected that power was not getting to the HRC and automatically shut down all three channels (see Hubble's key camera shuts down again). Now, the camera's Wide Field Channel (WFC) has resumed observations, with the other two channels still offline. The WFC, the channel that had been used for most ACS observations, gets its power from an independent route that is not affected by the other two channels. Switch issue :doh: Hubble began taking observations with the WFC on Sunday. "The instrument seems to be performing nominally," says Preston Burch, Hubble's mission manager at the Goddard Space Flight Center in Greenbelt, Maryland, US. Hubble engineers are now pretty sure that the problem with the other two channels is related to the mechanical relay that flips back and forth to send power to either the SBC or the HRC. "All indications are that the commands [to flip] were properly received by the spacecraft, but we're not seeing the voltage [expected]," Burch told New Scientist. There might be some dirt or debris that is preventing the switch from closing properly, he says. Another possibility is that the mechanism that moves the arms of the switch from one position to another is broken, he says. Short circuit Hubble's managers are thinking about trying to flip the switch back and forth, which could solve the problem by dislodging any dirt. However, there is some worry that if the switch itself is broken, moving it could cause a short circuit that would kill the ACS's power source. A short circuit is considered an unlikely event, but it would make all three channels unusable, Burch says. The Hubble team will meet on Wednesday to discuss what to do about the switch. "We're probably a couple days away from doing any on-orbit commanding of the hardware," Burch says. If the switch problem cannot be fixed, the High Resolution Camera may still be able to make observations, but with only half its original field of view.

Astronomers Gain Important Insight on How Massive Stars Form National Radio Astronomy Observatory Press Release September 27th, 2006 Source Link Astronomers using the National Science Foundation's Very Large Array (VLA) radio telescope have discovered key evidence that may help them figure out how very massive stars can form. "We think we know how stars like the Sun are formed, but there are major problems in determining how a star 10 times more massive than the Sun can accumulate that much mass. The new observations with the VLA have provided important clues to resolving that mystery," said Maria Teresa Beltran, of the University of Barcelona in Spain. Beltran and other astronomers from Italy and Hawaii studied a young, massive star called G24 A1 about 25,000 light-years from Earth. This object is about 20 times more massive than the Sun. The scientists reported their findings in the September 28 issue of the journal Nature. Stars form when giant interstellar clouds of gas and dust collapse gravitationally, compacting the material into what becomes the star. While astronomers believe they understand this process reasonably well for smaller stars, the theoretical framework ran into a hitch with larger stars. "When a star gets up to about eight times the mass of the Sun, it pours out enough light and other radiation to stop the further infall of material," Beltran explained. "We know there are many stars bigger than that, so the question is, how do they get that much mass?" One idea is that infalling matter forms a disk whirling around the star. With most of the radiation escaping without hitting the disk, material can continue to fall into the star from the disk. According to this model, some material will be flung outward along the rotation axis of the disk into powerful outflows. "If this model is correct, there should be material falling inward, rushing outward and rotating around the star all at the same time," Beltran said. "In fact, that's exactly what we saw in G24 A1. It's the first time all three types of motion have been seen in a single young massive star," she added. The scientists traced motions in gas around the young star by studying radio waves emitted by ammonia molecules at a frequency near 23 GHz. The Doppler shift in the frequency of the radio waves gave them the information on the motions of the gas. This technique allowed them to detect gas falling inward toward a large "doughnut," or torus, surrounding the disk presumed to be orbiting the young star. "Our detection of gas falling inward toward the star is an important milestone," Beltran said. The infall of the gas is consistent with the idea of material accreting onto the star in a non-spherical manner, such as in a disk. This supports that idea, which is one of several proposed ways for massive stars to accumulate their great bulk. Others include collisions of smaller stars. "Our findings suggest that the disk model is a plausible way to make stars up to 20 times the mass of the Sun. We'll continue to study G24 A1 and other objects to improve our understanding," Beltran said. Beltran worked with Riccardo Cesaroni and Leonardo Testi of the Astrophysical Observatory of Arcetri of INAF in Firenze, Italy, Claudio Codella and Luca Olmi of the Institute of Radioastronomy of INAF in Firenze, Italy, and Ray Furuya of the Japanese Subaru Telescope in Hawaii. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Artist's Conception of Young Star Showing Motions Detected in G24 A1:(1) Infall toward torus, (2) Rotation and (3) outflow. Note: Giant stars (25+ solar masses) are something of an enigma. How they form vs how other stars form has been a riddle that scientists studying stellar evolution have been looking into for years.

Japan launches Sun 'microscope' By Jonathan Amos Science reporter, BBC News Source Link Scientists have high hopes for Japan's Solar-B mission which has been launched from the Uchinoura spaceport. The spacecraft will investigate the colossal explosions in the Sun's atmosphere known as solar flares. These dramatic events release energy equivalent to tens of millions of hydrogen bombs in just a few minutes. The probe will attempt to find out more about the magnetic fields thought to power solar flares, and try to identify the trigger that sets them off. The ultimate goal for scientists is to use the new insights to make better forecasts of the Sun's behaviour. Flares can hurl radiation and super-fast particles in the direction of the Earth, disrupting radio signals, frying satellite electronics, and damaging the health of astronauts. Solar-B lifted off from Uchinoura, at the southern tip of Japan, at 0636 local time on Saturday (2136 GMT Friday). "It will take two to three weeks to transfer the spacecraft into its so-called Sun-synchronous polar orbit. From this position, Solar-B will be able to observe the Sun without having any nights for eight months of the year," said Professor Tetsuya Watanabe, of the National Astronomical Observatory of Japan (NAOJ). As is customary on Japanese missions, the satellite will get a new name once it is ready to begin its work. The spacecraft, developed by the Japanese space agency (Jaxa) and the Mitsubishi Electric Corporation, has scientific and engineering contributions from, principally, the US and the UK. 'Fine detail' The Sun behaves like a giant twisting magnet; and when contorted field lines that have lifted up off the surface of the star clash, they release a colossal maelstrom of energy. A blast of intense radiation is emitted, and charged particles are accelerated out into the Solar System. Some of these particles are moving so fast they can cover the 149 million km to Earth in just tens of minutes. Whilst scientists understand the flaring process reasonably well, they cannot predict when one of these enormous explosions will occur. Solar-B is expected to transform our understanding. It carries three instruments: a Solar Optical Telescope (SOT), an X-ray Telescope and an Extreme Ultraviolet Imaging Spectrometer. They will make continuous, simultaneous observations of specific solar features, to observe how changes in the magnetic field at the Sun's surface can spread through the layers of the solar atmosphere to produce, ultimately, a flare. "Solar-B acts essentially like a microscope, probing the fine details of what the magnetic field is doing as it builds up to a flare," said mission scientist Professor Louise Harra, from the Mullard Space Science Laboratory, UCL, UK. "What we don't know is what triggers a flare; we don't understand the physics of that phase at all. Solar-B will show us how tangled the field is, and how the field lines collide to produce all that energy." Space dependence Solar-B is but one of a fleet of spacecraft now dedicated to understanding the relationship between the Sun and the Earth; and more are set to follow. Next month, the US space agency (Nasa) plans to launch its Stereo mission - twin spacecraft that will make 3D observations of our star. As we become more reliant on space-based systems - to provide us with everything from timing and positioning services to the relay of telecoms data - the need to understand the tempestuous Sun-Earth interaction just gets more urgent. Losing a satellite because of solar flare effects could prove costly, not just in economic terms but in human lives. Spacecraft like Solar-B should give scientists the data they need to make better "space weather" forecasts. "The information that Solar-B will provide is significant for understanding and forecasting of solar disturbances, which can interfere with satellite communications, electric power transmission grids, and threaten the safety of astronauts travelling beyond the safety of the Earth's magnetic field," said John Davis, Solar-B project scientist at Nasa's Marshall centre. Scientists would like to predict the onset of solar flares which can have a tremendous impact on both earth and space based systems. [image credit: NASA/SOHO]

Something really awesome is happening on the web! The Royal Society of London is opening 340 years worth of its archives to the public until December. Now, free of charge, you have the oppertunity to download and look at the works of some of the giants of science like Hawkins, Einstien, Pauling, Chandrasekhar, Bohr, Herschel, Kelvin, Liebnitz, Maxwell, Newton, Rutherford and many, many more. Of course I'm biased towards the physical sciences, but biology is covered too. Watson, Crick and Edmond Stone's breakthrough in 1763 that willow bark cured fevers, leading to the discovery of salicylic acid and later the development of aspirin. This is an immeasurable treasure! For people that study or work in the sciences, this is a chance to see our understanding of chemistry, math, physics, biology evolved with time. For historians it is a chance to look at the impact of the earth shaking discoveries like gravity, electricity and DNA. Imagine having tea with Sir Isacc Newton or attending a lecture by Chandrasekhar. This rocks! I'm so going to be downloading like a maniac! 340 Years of Science

NASA's Hubble Finds Hundreds of Young Galaxies in Early Universe -------------------------------------------------------------------------------- NASA Press Release: September 21, 2006 PRESS RELEASE NO.: STScI-PR06-12 Source Link NASA'S HUBBLE FINDS HUNDREDS OF YOUNG GALAXIES IN EARLY UNIVERSE Astronomers analyzing two of the deepest views of the cosmos made with NASA's Hubble Space Telescope have uncovered a gold mine of galaxies, more than 500 that existed less than a billion years after the Big Bang. These galaxies thrived when the cosmos was less than 7 percent of its present age of 13.7 billion years. This sample represents the most comprehensive compilation of galaxies in the early universe, researchers said. The discovery is scientifically invaluable for understanding the origin of galaxies, considering that just a decade ago early galaxy formation was largely uncharted territory. Astronomers had not seen even one galaxy that existed when the universe was a billion years old, so finding 500 in a Hubble survey is a significant leap forward for cosmologists. The galaxies unveiled by Hubble are smaller than today's giant galaxies and very bluish in color, indicating they are ablaze with star birth. The images appear red because of the galaxies' tremendous distance from Earth. The blue light from their young stars took nearly 13 billion years to arrive at Earth. During the journey, the blue light was shifted to red light due to the expansion of space. "Finding so many of these dwarf galaxies, but so few bright ones, is evidence for galaxies building up from small pieces

A 'Genetic Study' Of The Galaxy Galactic Bulge and Disc Stars Shown To Have Different Oxygen Abundances ESO 34/06 - Science Release 12 September 2006 Source Link Part of one of the four regions of the sky in the direction of the Galactic Bulge in which the astronomers measured the iron and oxygen abundances in stars. This particular field is in the vicinity of the so-called 'Baade's Window', a region with relatively low amounts of interstellar "dust" that could block the sight, allowing astronomers to peer into the central parts of the Milky Way galactic centre and beyond. The globular cluster NGC 6528 is visible in the lower left corner. The image is a colour composite, based on images obtained in the B-, V-, and I-filters with the FORS instrument on the ESO VLT. The images were extracted from the ESO Science Archive and processed by Henri Boffin (ESO). North is to the right and East on top. _________________________________________________________________ Galactic Bulge and Disc Stars Shown To Have Different Oxygen Abundances Looking in detail at the composition of stars with ESO's VLT, astronomers are providing a fresh look at the history of our home galaxy, the Milky Way. They reveal that the central part of our Galaxy formed not only very quickly but also independently of the rest. "For the first time, we have clearly established a 'genetic difference' between stars in the disc and the bulge of our Galaxy," said Manuela Zoccali, lead author of the paper presenting the results in the journal Astronomy and Astrophysics [1]. "We infer from this that the bulge must have formed more rapidly than the disc, probably in less than a billion years and when the Universe was still very young." The Milky Way is a spiral galaxy, having pinwheel-shaped arms of gas, dust, and stars lying in a flattened disc, and extending directly out from a spherical nucleus of stars in the central region. The spherical nucleus is called a bulge, because it bulges out from the disc. While the disc of our Galaxy is made up of stars of all ages, the bulge contains old stars dating from the time the galaxy formed, more than 10 billion years ago. Thus, studying the bulge allows astronomers to know more about how our Galaxy formed. To do this, an international team of astronomers [2] analysed in detail the chemical composition of 50 giant stars in four different areas of the sky towards the Galactic bulge. They made use of the FLAMES/UVES spectrograph on ESO's Very Large Telescope to obtain high-resolution spectra. The chemical composition of stars carries the signature of the enrichment processes undergone by the interstellar matter up to the moment of their formation. It depends on the previous history of star formation and can thus be used to infer whether there is a 'genetic link' between different stellar groups. In particular, comparison between the abundance of oxygen and iron in stars is very illustrative. Oxygen is predominantly produced in the explosion of massive, short-lived stars (so-called Type II supernovae), while iron instead originates mostly in Type Ia supernovae [3], which can take much longer to develop. Comparing oxygen with iron abundances therefore gives insight on the star birth rate in the Milky Way's past. Ratio of Oxygen over Iron abundance as a function of the iron content in stars (both axis are using logarithmic scales). The green circle denotes the stars in the Bulge studied by the present astronomers, while the yellow triangles and blue crosses are previous data obtained for stars in the disc of our Galaxy. The bulge stars are clearly more oxygen-rich than disc stars, highlighting the 'genetic difference' between the bulge and disc stars. _________________________________________________________________ "The larger size and iron-content coverage of our sample allows us to draw much more robust conclusions than were possible until now," said Aurelie Lecureur, from the Paris-Meudon Observatory (France) and co-author of the paper. The astronomers clearly established that, for a given iron content, stars in the bulge possess more oxygen than their disc counterparts. This highlights a systematic, hereditary difference between bulge and disc stars. "In other words, bulge stars did not originate in the disc and then migrate inward to build up the bulge but rather formed independently of the disc," said Zoccali. "Moreover, the chemical enrichment of the bulge, and hence its formation timescale, has been faster than that of the disc." Comparisons with theoretical models indicate that the Galactic bulge must have formed in less than a billion years, most likely through a series of starbursts when the Universe was still very young. Notes [1]: "Oxygen abundances in the Galactic bulge: evidence for fast chemical enrichment" by Zoccali et al. It is freely available from the publisher's web site as a PDF file. [2]: The team is composed of Manuela Zoccali and Dante Minniti (Universidad Catolica de Chile, Santiago), Aurelie Lecureur, Vanessa Hill and Ana Gomez (Observatoire de Paris-Meudon, France), Beatriz Barbuy (Universidade de Sao Paulo, Brazil), Alvio Renzini (INAF-Osservatorio Astronomico di Padova, Italy), and Yazan Momany and Sergio Ortolani (Universita di Padova, Italy). [3]: Type Ia supernovae are a sub-class of supernovae that were historically classified as not showing the signature of hydrogen in their spectra. They are currently interpreted as the disruption of small, compact stars, called white dwarfs, that acquire matter from a companion star. A white dwarf represents the penultimate stage of a solar-type star. The nuclear reactor in its core has run out of fuel a long time ago and is now inactive. However, at some point the mounting weight of the accumulating material will have increased the pressure inside the white dwarf so much that the nuclear ashes in there will ignite and start burning into even heavier elements. This process very quickly becomes uncontrolled and the entire star is blown to pieces in a dramatic event. An extremely hot fireball is seen that often outshines the host galaxy. PDF of Zoccali, et al- Oxygen Abundances in the Galactic Halo

Spacecraft strikes Moon with intense flash September 3, 2006 Hazel Muir for NewScientist.com Source Link The SMART-1 lunar probe crashed into the Moon right on cue on Sunday morning. Mission controllers at the European Space Agency lost contact with the probe at 0542 GMT, indicating that it had struck close to the planned landing site on the lunar

Astronomers lean toward eight planets August 22, 2006 Stephen Battersby, Prague NewScientist.com Source Link Finally, astronomers could be homing in on a definition of the word planet. After a day of public bickering in Prague, followed by negotiations behind closed doors, the latest draft resolution was greeted with a broadly friendly reception. If accepted on Thursday, it would be bad news for Pluto, which would no longer be a full-fledged planet. The crucial change in "draft c" is that a planet must be the dominant body in its orbital zone, clearing out any little neighbours. Pluto does not qualify because its orbit crosses that of the vastly larger Neptune. The planet definition committee is also stepping back from trying to define all planets in the universe, and sticking to our solar system

Nine Planets Become 12 with Controversial New Definition Robert Roy Britt, Senior Science Writer August 16, 2006 Source Link The 12 planets under the newly proposed IAU definition. Planet sizes are shown to scale but their orbital distances are not to scale. Credit: IAU/Martin Kornmesser In proposing a new planet definition, the International Astronomical Union put 12 objects on a watch list of candidates that need further study. They are shown here to scale with Earth. Credit: IAU/Martin Kornmesser _____________________________________________________________________ The tally of planets in our solar system would jump instantly to a dozen under a highly controversial new definition proposed by the International Astronomical Union (IAU). Eventually there would be hundreds as more round objects are found beyond Neptune. The proposal, which sources tell SPACE.com is gaining broad support, tries to plug a big gap in astronomy textbooks, which have never had a definition for the word "planet." It addresses discoveries of Pluto-sized worlds that have in recent years pitched astronomers into heated debates over terminology. The asteroid Ceres, which is round, would be recast as a dwarf planet in the new scheme. Pluto would remain a planet and its moon Charon would be reclassified as a planet. Both would be called "plutons," however, to distinguish them from the eight "classical" planets. A far-out Pluto-sized object known as 2003 UB313 would also be called a pluton. That would make Caltech researcher Mike Brown, who found 2003 UB313, formally the discoverer of the 12th planet. But he thinks it's a lousy idea. "It's flattering to be considered discoverer of the 12th planet," Brown said in a telephone interview. He applauded the committee's efforts but said the overall proposal is "a complete mess." By his count, the definition means there are already 53 known planets in our solar system with countless more to be discovered. Brown and other another expert said the proposal, to be put forth Wednesday at the IAU General Assembly meeting in Prague, is not logical. For example, Brown said, it does not make sense to consider Ceres and Charon planets and not call our Moon (which is bigger than both) a planet. IAU members will vote on the proposal Thursday, Aug. 24. Its fate is far from clear. The definition The definition, which basically says round objects orbiting stars will be called planets, is simple at first glance: "A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and ( is in orbit around a star, and is neither a star nor a satellite of a planet." "Our goal was to find a scientific basis for a new definition of planet and we chose gravity as the determining factor," said Richard Binzel, an MIT planetary scientist who was part of a seven-member IAU committee that hashed out the proposal. "Nature decides whether or not an object is a planet." "I think they did the right thing," said Alan Stern, a planetary scientist at the Southwest Research Institute and leader of NASA's New Horizons robotic mission to Pluto. Stern expects a consensus to form around the proposal. "They chose a nice economical definition that a lot of us wanted to see," Stern told SPACE.com. "A lot of the other definitions had big problems. This is the only one that doesn't have big problems."