UFO Photograph Hailed as One of the Best

This photo of a UFO over Cornwall is hailed by experts as one of the best ever taken in Britain.

UFO sightings at Cornwall 55-year-old Kelvin Barbery snapped the mystery object on Dec 29 (2007) from a coastal path between Swanpool and Maenporth, near Falmouth.

In a weird twist, Kelvin did not even see the UFO at the time. He thought he was just taking a sea view… but when he loaded the digital camera card on to his computer, the round metallic ‘craft’ was in the centre of the shot, about two miles away.

This news surprisingly didn’t make it big on international papers. Perhaps people are getting bored over pictures, reports, news and videos about UFO sightings, which are often found as fraud in the end.

Saturn's Largest Moon TITAN Is Tropical In Nature

If space travelers ever visit Saturn's largest moon, they will find a tropical world where temperatures plunge to minus 274 degrees Fahrenheit, methane rains from the sky and dunes of ice or tar cover the planet's most arid regions. These conditions reflect a cold mirror image of Earth's tropical climate, according to scientists at the University of Chicago.

"You have all these things that are analogous to Earth. At the same time, it's foreign and unfamiliar," said Ray Pierrehumbert, the Louis Block Professor in Geophysical Sciences at Chicago.

Titan, one of Saturn's 60 moons, is the only moon in the solar system large enough to support an atmosphere. Pierrehumbert and Jonathan Mitchell, who recently completed his Ph.D. in Astronomy & Astrophysics at Chicago, have been comparing observations of Titan collected by the Cassini space probe and the Hubble Space Telescope with their own computer simulations of the moon's atmosphere.

Their study of the dynamics behind Titan's methane clouds have appeared in the Proceedings of the National Academy of Sciences. Their continuing research on Titan's climate focuses on the moon's deserts.

"One of the things that attracts me about Titan is that it has a lot of the same circulation features as Earth, but done with completely different substances that work at different temperatures," Pierrehumbert said. On Earth, for example, water forms liquid and is relatively active as a vapor in the atmosphere. But on Titan, water is a rock.

"It's not more volatile on Titan than sand is on Earth."

Methane-natural gas-assumes an Earthlike role of water on Titan. It exists in enough abundance to condense into rain and form puddles on the surface within the range of temperatures that occur on Titan.

"The ironic thing on Titan is that although it's much colder than Earth, it actually acts like a super-hot Earth rather than a snowball Earth, because at Titan temperatures, methane is more volatile than water vapor is at Earth temperatures," Pierrehumbert said.

Pierrehumbert and Mitchell even go so far as to call Titan's climate tropical, even though it sounds odd for a moon that orbits Saturn more than nine times farther from the sun than Earth. Along with the behavior of methane, Titan's slow rotation rate also contributes to its tropical nature. Earth's tropical weather systems extend only to plus or minus 30 degrees of latitude from the equator. But on Titan, which rotates only once every 16 days, "the tropical weather system extends to the entire planet," Pierrehumbert said.

Titan's tropical nature means that scientists can observe the behavior of its clouds using theories they've relied upon to understand Earth's tropics, Mitchell noted.Titan's atmosphere produces an updraft where surface winds converge. This updraft lifts evaporated methane up to cooler temperatures and lower pressures, where much of it condenses and forms clouds.

"This is a well-known feature on Earth called an ITCZ, the inter-tropical convergence zone," Mitchell said. Earth's oceans help confine the ITCZ to the lowest latitudes. But in some scenarios for oceanless Titan, the ITCZ in Mitchell's computer simulations wanders in latitude almost from one pole to the other. Titan's clouds should also follow the ITCZ.

Titan's orange atmospheric haze complicates efforts to observe the moon's clouds. "This haze shrouds the entire surface," Mitchell said. "It pretty much blocks all visible light from reaching us from the surface or from the lower atmosphere."

Nevertheless, infrared observations via two narrow frequency bands have recently revealed that clouds are currently confined to the moon's southern hemisphere, which is just now emerging from its summer season.

"There should be a very large seasonality in these cloud features," Mitchell said. "Cassini and other instruments might be able to tell us about that in the next seven to 10 years or so, as the seasons progress."

Mitchell and Pierrehumbert's next paper will describe how oscillations in Titan's atmospheric circulation dry out the moon's midsection. Over the course of a year, Mitchell explained, "this oscillation in the atmosphere tends to transport moisture, or evaporated methane, out of the low latitudes and then deposit it at mid and high latitude in the form of rainfall. This is interesting, because recent Cassini observations of the surface suggest that the low latitudes are very dry."

Cassini images show dunes of ice or tar covering these low-latitude regions that correspond to the tropics on Earth. When ultraviolet light from the sun interacts with methane high in Titan's atmosphere, it creates byproducts such as ethane and hydrogen.

These byproducts become linked to chains of hydrocarbon molecules that create Titan's orange haze. When these molecules coalesce into large particles, they settle out as a tar-like rain.

"Titan is like a big petrochemical plant," Pierrehumbert said. "Although this is all happening at a much lower temperature than in a petroleum refinery, the basic processes going on there are very closely allied to what people do when they make fuel."

Source : This story has been adapted from material provided by University of Chicago.

500 days at Venus, and the surprises keep coming

These images were taken in eight orbits within 10 consecutive Earth days (between orbits 299 and 309) with VIRTIS, in February 2007. The chosen wavelength was approximately 2.3 micrometres. The images were all taken on the night side, in the evening sector. The quarter that is observed is that which is experiencing late evening, or pre-midnight hours. It should be taken into account that Venus rotates very slowly as compared to Earth (one venusian day is 243 Earth days). The distances from the spacecraft to the region observed span 50 000 to 65 000 km. The contrast seen results from deeper cloud layers, at an altitude of about 50 km. The south pole is just outside the image, in the upper right hand side. It seems that the mid latitudes form a sort of transition region with mostly laminar flow. Moving equatorward, there is more convective flow in the atmosphere, whereas the polar region or the ‘black hole’ in the upper right hand side is where the vortex dominates. The meteorology of the planet, also its deep atmosphere, is highly variable. The images in the bottom row as well as the leftmost image in the middle row show laminar flow. The rest of the images show turbulent flow. Intense, bright colours show less cloudy areas, while darker, black areas, show more cloudy regions. This is because radiation coming from hotter regions below the clouds is blocked by thicker clouds. Credits: ESA/ VIRTIS/ INAF-IASF/ Obs. de Paris-LESIA
Venus Express has now orbited Earth’s twin for 500 Earth days, completing as many orbits. While the satellite maintains steady and excellent performance, the planet continues to surprise and amaze us.

In spite of experiencing a challenging environment, Venus Express is in an excellent condition. It receives four times the amount of solar radiation as compared to its sister spacecraft, Mars Express, but modifications to the spacecraft design have worked just as intended and operation has been very stable.
Many different activities transpire on board with each orbit: instruments are switched on and off, they change modes and targets and the spacecraft checks out and monitors its subsystems more or less continuously. The few anomalies that occurred were quickly resolved by vigilant spacecraft controllers.

An impressive amount of data - about 1 Terabits, or one million million bits - has been transmitted to Earth over the first 500 days.

Håkan Svedhem, Venus Express Project Scientist says, "The scientists analysing the data have a challenging but exciting task ahead.” They will have to archive the data and extract the most important detail from this immense collection of images, spectra and profiles of temperature, pressure and chemical composition.

Some of the first detailed analyses are now being completed and will soon be published in acclaimed scientific journals. Among many other findings that have surprised scientists, Venus’ atmosphere seems extremely fickle. Recent observations with the Visible and Near-Infrared Mapping Spectrometer (VIRTIS), the atmospheric structure changes quite rapidly, from day to day.

Source: ESA

Supersonic 'rain' falls on newborn star

Astronomers at the University of Rochester have discovered five Earth-oceans’ worth of water that has recently fallen into the planet-forming region around an extremely young, developing star.
Dan Watson, professor of physics and astronomy at the University of Rochester, believes he and his colleagues are the first to see a short-lived stage of protoplanetary disk formation, and the manner in which a planetary system’s supply of water arrives from the natal envelope within which its parent star originally formed.

The findings, published in today’s Nature, are the first-ever glimpse of material directly feeding a protoplanetary disk.

The embryonic star in question, called IRAS 4B, lies in a picturesque nebula called NGC 1333, about 1000 light years from Earth. It is one of an initial list of 30 of the youngest “protostars” known, which Watson and his team examined with the Spitzer Space Telescope’s infrared spectrograph for signs of very dense, warm material at their cores. It is also the only one of the thirty to show signs of such material, signaled by the infrared spectrum of water vapor. The watery characteristics of IRAS4B’s infrared spectrum can best be explained by material falling from the protostar’s envelope onto a surrounding, dense disk. This setup, called by astronomers a “disk-accretion shock,” is the formative mechanism of the disks within which all planetary systems are thought to originate.

“Icy material from the envelope is in free-fall, reaching supersonic speeds and crashing into the protoplanetary disk.” says Watson. “The ice vaporizes on impact, and the warm water vapor emits a distinctive spectrum of infrared light. That light is what we measured. From the details of the measured spectrum we can tease out the physical details of this brand-new, pre-planetary disk”

Among the details derived so far are the rate of “rainfall” onto the disk – about 23 Earth masses per year – and the characteristics of the “puddle” on the disk’s surface: The surface is 170 degrees Kelvin (153 degrees below zero Fahrenheit), and at that temperature there is about an Earth’s mass worth of material, including enough water to fill Earth’s oceans about five times. The area of the “puddle” is such that, if circular and centered on the Sun, its perimeter would be just beyond the orbit of Pluto. Results such as this will help astronomers assess the early planet-forming potential of IRAS4B’s disk, and by inference learn about the earliest stages of our solar system’s life.

There are astro-chemical implications of the observations as well. “There are lots of primitive icy bodies in our solar system, and the ice they carry is often thought to descend directly from the interstellar medium, so that by studying one we could learn about the other,” says Watson. “But in NGC 1333 IRAS 4B’s disk, it is clear that the water is received as vapor and will be re-frozen under different conditions, and this means that the oxygen and hydrogen chemistry of its disk is reset from interstellar conditions. It’s not getting pristine, interstellar ice.” Astronomers at the University of Rochester, including Watson and co-author professor William Forrest, helped design the “eyes” of Spitzer specifically to look for objects like IRAS4B and its water because such objects sit in an astronomer’s blind spot. Called “Class Zero Protostars” for their extreme youth, these objects radiate substantial light only at long infrared wavelengths, which our atmosphere inconveniently blocks from ground-based telescopes. When Watson and his team first planned their Spitzer observations, only 50 class-zero protostars were known, and the team selected the 30 brightest. But Watson says that’s just the beginning. Astronomers now know of hundreds of such objects, and Watson expects to have thousands to investigate in the coming years.

Another characteristic makes the otherwise un-noteworthy IRAS4B a rarity. It is oriented with its axis pointed almost directly at Earth, splaying out its entire disk to our view and simplifying the process of plumbing its secrets. Only a small fraction of the future candidates are expected be similarly oriented, keeping the search for lots more “raining protostars” a challenge.

Source: University of Rochester

Exploding Lunar Eclipse

On Tuesday morning, Aug. 28th, Earth's shadow will settle across the Moon for a 90-minute total eclipse. In the midst of the lunar darkness, Cooke hopes to record some flashes of light--explosions caused by meteoroids crashing into the Moon and blasting themselves to smithereens.

"The eclipse is a great time to look," says Cooke, who heads up NASA's Meteoroid Environment Office (MEO) at the Marshall Space Flight Center. The entire face of the Moon will be in shadow for more than two hours, offering more than 7 million sq. miles of dark terrain as target for incoming meteoroids.

Lunar explosions are nothing new. Cooke's team has been monitoring the Moon since late 2005 and they've recorded 62 impacts so far. "Meteoroids that hit Earth disintegrate in the atmosphere, producing a harmless streak of light. But the Moon has no atmosphere, so 'lunar meteors' plunge into the ground," he says. Typical strikes release as much energy as 100 kg of TNT, gouging craters several meters wide and producing bursts of light bright enough to be seen 240,000 miles away on Earth through ordinary backyard telescopes.

"About half of the impacts we see come from regular meteor showers like the Perseids and Leonids," says MEO team-member Danielle Moser. "The other half are 'sporadic' meteors associated with no particular asteroid or comet."

The MEO observatory is located on the grounds of the Marshall Space Flight Center in Huntsville, Alabama, and consists of two 14-inch telescopes equipped with sensitive low-light video cameras. Moser and colleague Victoria Coffey will be on duty Tuesday morning.

During the eclipse, they hope to catch an elusive variety of meteor called Helions.

"Helion meteoroids come from the direction of the sun," Cooke says, "and that makes them very difficult to observe." They streak across the sky most often around local noon when the sun's glare is too intense for meteor watching.

Wait a minute. Meteors from the sun? "The sun itself is not the source," he explains. "We believe Helion meteoroids come from ancient sungrazing comets that laid down trails of dusty debris in the vicinity of the sun."

No one can be certain, however, because Helion meteoroids are so devilishly difficult to study. Astronomers see them only in small numbers briefly before dawn or after sunset. Attempts to study Helions via radar during the day have been foiled, to a degree, by terrestrial radio interference and natural radio bursts from the sun—both of which can drown out meteoroid "pings."

Enter the eclipse.

During the eclipse, the Man in the Moon (the face we see from Earth) will be turned squarely toward the sun—"perfect geometry for intercepting Helion meteoroids," says Moser. "And with Earth's shadow providing some darkness, we should be able to see any explosions quite clearly."

"Watching Helion meteoroids hit the Moon and studying the flashes will tell us more about their size, velocity and penetration," she adds. That, in turn, will further the MEO's goal of estimating meteoroid hazards to spacecraft and future Moon-walking astronauts.

No one has ever seen a lunar impact during an eclipse, "but there's a first time for everything," Cooke says.

Source: Science@NASA, by Dr. Tony Phillips

Dreamy Lunar Eclipse

Close your eyes, breathe deeply, let your mind wander to a distant seashore: It's late in the day, and the western sun is sinking into the glittering waves. At your feet, damp sand reflects the twilight, while overhead, the deep blue sky fades into a cloudy mélange of sunset copper and gold, so vivid it almost takes your breath away.

A breeze touches the back of your neck, and you turn to see a pale full Moon rising into the night. Hmmm. The Moon could use a dash more color. You reach out, grab a handful of sunset, and drape the Moon with phantasmic light. Much better.

Too bad it's only a dream...

Early Tuesday morning, August 28th, the dream will come true. There's going to be a colorful lunar eclipse visible from five continents including most of North America: map.

The event begins 54 minutes past midnight PDT (0754 UT) on August 28th when the Moon enters Earth's shadow. At first, there's little change. The outskirts of Earth's shadow are as pale as the Moon itself; an onlooker might not even realize anything is happening. But as the Moon penetrates deeper, a startling metamorphosis occurs. Around 2:52 am PDT (0952 UT), the color of the Moon changes from moondust-gray to sunset-red. This is totality, and it lasts for 90 minutes.

To understand why the change occurs, close your eyes and dream yourself all the way to the Moon. Once again, you're standing on a seashore—the Sea of Tranquillity. There's no water. You're surrounded by hundreds of miles of dusty, hardened lava. Overhead hangs Earth, nightside down, completely hiding the Sun behind it. The eclipse is underway.

With the Sun blocked, you might expect utter darkness, but no, the ground at your feet is aglow. Why? Look back up at Earth. The rim of the planet seems to be on fire. Around Earth's circumference you see every sunrise and sunset in the world—all at once. This incredible light beams into the heart of Earth's shadow, transforming the Moon into a landscape of copper moondust and golden hills.

Wake up! This is really going to happen, and some planning is necessary. Start times of totality are listed in the table below. Set your alarm an hour or so in advance to gather snacks and dress warmly. (Even in August, four o'clock in the morning can be chilly.) Waking up early also allows you to catch some of the partial eclipse before totality.

The eclipse will be visible from Australia, Japan, parts of Asia and most of the Americas, but not from Africa or Europe. Pacific observers are favored. On the west coast of the United States, the entire eclipse will unfold high in the post-midnight sky. On the east coast, totality will be truncated by sunrise. That's okay; even a little eclipse can be a dream.

...nasa...

Astronomers find gaping hole in the Universe

University of Minnesota astronomers have found an enormous hole in the Universe, nearly a billion light-years across, empty of both normal matter such as stars, galaxies and gas, as well as the mysterious, unseen “dark matter.” While earlier studies have shown holes, or voids, in the large-scale structure of the Universe, this new discovery dwarfs them all.

Astronomers have known for years that, on large scales, the Universe has voids largely empty of matter. However, most of these voids are much smaller than the one found by Rudnick and his colleagues. In addition, the number of discovered voids decreases as the size increases.

“What we’ve found is not normal, based on either observational studies or on computer simulations of the large-scale evolution of the Universe,” Williams said.

The astronomers drew their conclusion by studying data from the NRAO VLA Sky Survey (NVSS), a project that imaged the entire sky visible to the Very Large Array (VLA) radio telescope, part of the National Science Foundation's National Radio Astronomy Observatory (NRAO). Their study of the NVSS data showed a remarkable drop in the number of galaxies in a region of sky in the constellation Eridanus, southwest of Orion.

“We already knew there was something different about this spot in the sky,” Rudnick said. The region had been dubbed the “WMAP Cold Spot,” because it stood out in a map of the Cosmic Microwave Background (CMB) radiation made by the Wilkinson Microwave Anisotopy Probe (WMAP) satellite, launched by NASA in 2001. The CMB, faint radio waves that are the remnant radiation from the Big Bang, is the earliest “baby picture” available of the Universe. Irregularities in the CMB show structures that existed only a few hundred thousand years after the Big Bang.

The WMAP satellite measured temperature differences in the CMB that are only millionths of a degree. The cold region in Eridanus was discovered in 2004.

Astronomers wondered if the cold spot was intrinsic to the CMB, and thus indicated some structure in the very early Universe, or whether it could be caused by something more nearby through which the CMB had to pass on its way to Earth. Finding the dearth of galaxies in that region by studying NVSS data resolved that question.

“Although our surprising results need independent confirmation, the slightly lower temperature of the CMB in this region appears to be caused by a huge hole devoid of nearly all matter roughly 6-10 billion light-years from Earth,” Rudnick said.

How does a lack of matter cause a lower temperature in the Big Bang’s remnant radiation as seen from Earth"

The answer lies in dark energy, which became a dominant force in the Universe very recently, when the Universe was already three-quarters of the size it is today. Dark energy works opposite gravity and is speeding up the expansion of the Universe. Thanks to dark energy, CMB photons that pass through a large void just before arriving at Earth have less energy than those that pass through an area with a normal distribution of matter in the last leg of their journey.

In a simple expansion of the universe, without dark energy, photons approaching a large mass -- such as a supercluster of galaxies -- pick up energy from its gravity. As they pull away, the gravity saps their energy, and they wind up with the same energy as when they started.

But photons passing through matter-rich space when dark energy became dominant don't fall back to their original energy level. Dark energy counteracts the influence of gravity and so the large masses don’t sap as much energy from the photons as they pull away. Thus, these photons arrive at Earth with a slightly higher energy, or temperature, than they would in a dark energy-free Universe.

Conversely, photons passing through a large void experience a loss of energy. The acceleration of the Universe's expansion, and thus dark energy, were discovered less than a decade ago. The physical properties of dark energy are unknown, though it is by far the most abundant form of energy in the Universe today. Learning its nature is one of the most fundamental current problems in astrophysics.

Source: University of Minnesota

A Star with a Comet's Tail

Astronomers using a NASA space telescope, the Galaxy Evolution Explorer, have spotted an amazingly long comet-like tail behind a star streaking through space. The star, named Mira after the Latin word for "wonderful," has been a favorite of astronomers for about 400 years, yet this is the first time the tail has been seen.

Galaxy Evolution Explorer--"GALEX" for short--scanned the popular star during its ongoing survey of the entire sky in ultraviolet light. Astronomers then noticed what looked like a comet with a gargantuan tail. In fact, material blowing off Mira is forming a wake 13 light-years long, or about 20,000 times the average distance of Pluto from the sun. Nothing like this has ever been seen before around a star.


"I was shocked when I first saw this completely unexpected, humongous tail trailing behind a well-known star," says Christopher Martin of the California Institute of Technology. "It was amazing how Mira's tail echoed on vast, interstellar scales the familiar phenomena of a jet's contrail or a speedboat's turbulent wake." Martin is the principal investigator for the Galaxy Evolution Explorer, and lead author of a Nature paper appearing today to announce the discovery.

Astronomers say Mira's tail offers a unique opportunity to study how stars like our sun die and ultimately seed new solar systems. Mira is an older star called a red giant that is losing massive amounts of surface material. As Mira hurtles along, its tail sheds carbon, oxygen and other important elements needed for new stars, planets and possibly even life to form. This tail material, visible now for the first time, has been released over the past 30,000 years.

"This is an utterly new phenomenon to us, and we are still in the process of understanding the physics involved," says co-author Mark Seibert of the Observatories of the Carnegie Institution of Washington in Pasadena. "We hope to be able to read Mira's tail like a ticker tape to learn about the star's life."

Billions of years ago, Mira was similar to our sun. Over time, it began to swell into what's called a variable red giant - a pulsating, puffed-up star that periodically grows bright enough to see with the naked eye. Mira will eventually eject all of its remaining gas into space, forming a colorful shell called a planetary nebula. The nebula will fade with time, leaving only the burnt-out core of the original star, which will then be called a white dwarf.

Compared to other red giants, Mira is traveling unusually fast, possibly due to gravitational boosts from other passing stars over time. It now plows along at 130 kilometers per second, or 291,000 miles per hour. Racing along with Mira is a small, distant companion thought to be a white dwarf. The pair, also known as Mira A (the red giant) and Mira B (the white dwarf), orbit slowly around each other as they travel together through the constellation Cetus 350 light-years from Earth.

In addition to Mira's tail, GALEX also discovered a bow shock, a type of buildup of hot gas, in front of the star, and two sinuous streams of material coming out of the star's front and back. Astronomers think hot gas in the bow shock is heating up the gas blowing off the star, causing it to fluoresce with ultraviolet light. This glowing material then swirls around behind the star, creating a turbulent, tail-like wake. The process is similar to a speeding boat leaving a choppy wake, or a steam train producing a trail of smoke.

The fact that Mira's tail only glows with ultraviolet light might explain why other telescopes have missed it. GALEX is very sensitive to ultraviolet light and also has an extremely wide field of view, allowing it to scan the sky for unusual ultraviolet activity.

"It's amazing to discover such a startlingly large and important feature of an object that has been known and studied for over 400 years," says James D. Neill of Caltech. "This is exactly the kind of surprise that comes from a survey mission like the Galaxy Evolution Explorer."