Posts Tagged ‘Space’

Brain

The idea of the universe as a ‘giant brain’ has been proposed by scientists – and science fiction writers – for decades.

But now physicists say there may be some evidence that it’s actually true. In a sense.

According to a study published in Nature’s Scientific Reports, the universe may be growing in the same way as a giant brain – with the electrical firing between brain cells ‘mirrored’ by the shape of expanding galaxies.

The results of a computer simulation suggest that “natural growth dynamics” – the way that systems evolve – are the same for different kinds of networks – whether its the internet, the human brain or the universe as a whole.

A co-author of the study, Dmitri Krioukov from the University of California San Diego, said that while such systems appear very different, they have evolved in very similar ways.

The result, they argue, is that the universe really does grow like a brain.

The study raises profound questions about how the universe works, Krioukov said.

“For a physicist it’s an immediate signal that there is some missing understanding of how nature works,” he told Space.com.

The team’s simulation modelled the very early life of the universe, shortly after the big bang, by looking at how quantum units of space-time smaller than subatomic particles ‘networked’ with each other as the universe grew.

They found that the simulation mirrored that of other networks. Some links between similar nodes resulted in limited growth, while others acted as junctions for many different connections.

For instance, some connections are limited and similar – like a person who likes sports visiting many other sports websites – and some are major and connect to many other parts of the network, like Google and Yahoo.

No, it doesn’t quite mean that the universe is ‘thinking’ – but as has been previously pointed out online, it might just mean there’s more similarity between the very small and the very large than first appearances suggest.

Huffington Post UK  |  By Michael Rundle

The sci-fi TV show Fringe often shows us an alternate, more technologically advanced version of Earth where airships are, for some reason, the norm. Now reality is mirroring fiction as a new project being developed in conjunction with the Pentagon is looking to bring airships back from their spotty past and into the future.

Developed by Aeroscraft, the 230-foot-long prototype airship called the Pelican is designed to lift up to 10 tons of cargo across long distances, using a fraction of the fuel needed by an airplane. The airship, which, interestingly, looks a lot like a flying saucer, has been in the works for several years under the guidance of the Pentagon’s Rapid Reaction Technology Office. In addition to cargo missions, the Pentagon also envisions the airship as a potential tool for surveillance and reconnaissance missions.The current prototype is much smaller than the final version of the airship the company plans to build which will be 450-feet long and have the ability to carry up to 66 tons of cargo. You can see footage of the Pelican being tested, as well as a presentation video depicting military uses for the airship in the videos below.

Aeroscraft, via AviationWeek

 

Black Hole Blast Biggest Ever Recorded

Posted: November 29, 2012 by phaedrap1 in News, Science
Tags: ,
Explosion is at least five times more powerful than previously observed events.

An illustration of a powerful burst of material ejected from a quasar.

Material is ejected near a supermassive black hole in the quasar SDSS J1106+1939 in an illustration.

Illustration courtesy L. Calçada, ESO

Andrew Fazekas

for National Geographic News

Published November 28, 2012

Astronomers have witnessed a record-breaking blast of gas and dust flowing out of a monster black hole more than 11.5 billion light-years away.

The supermassive gravity well, with a mass of one to three billion suns, lurks at the core of a quasar—a class of extremely bright and energetic galaxies—dubbed SDSS J1106 1939. (See “Black Hole Blasts Superheated Early Universe.”)

“We discovered the most energetic quasar outflow ever seen, at least five times more powerful than any that have been observed to date,” said Nahum Arav, an astronomer at Virginia Tech and co-author of the study to be published in The Astrophysical Journal.

Using the powerful telescopes of the European Southern Observatory in Chile, Arav and his team were able to clock the speed and other properties of the outflow.

Belching out material as much as 400 times the weight of our sun every year, the blast is located nearly a thousand light-years from the quasar and has a velocity of roughly 18 million miles (29 million kilometers) per hour.

“We were hoping to see something like this, but the sheer power of this outflow still took us by surprise,” said Arav.

The central black hole in this quasar is true giant dynamo. It’s estimated to be upward of a thousand times more massive than the one in the Milky Way, producing energy at rates about a hundred times higher than the total power output of our galaxy. (See black hole pictures.)

Clues to Galaxy Evolution

Supermassive black holes are large enough to swallow our entire solar system and are notorious for ripping apart and swallowing stars. But they also power distant quasars and spew out material at high speeds.

(See “Monster Black Holes Gobble Binary Stars to Grow?”)

The outflows have been suspected to play a key role in the evolution of galaxies, explained Arav, but questions have persisted for years in the astronomical community as to whether they were powerful enough.

This newly discovered super outflow could solve major cosmic mysteries, including how the mass of a galaxy is linked to its central black hole mass and why there is a relative scarcity of large galaxies across the universe.

“I believe this is the smoking gun for several theoretical ideas that use the mechanical energy output of quasars to solve several important problems in the formation of galaxies and cluster of galaxies,” said Arav.

While Kirk Korista, an astronomer not connected to the study, believes these claims may be a bit premature, the research is expected to shed new light on the most powerful and least understood portions of typical quasar outflows.

“The superb spectroscopic data of this quasar have allowed for a breakthrough in quantifying the energetics of what is probably a typical quasar outflow,” said Korista, an astronomy professor at Western Michigan University.

“This definitely is an important step in piecing together the story of galaxy evolution, and in elucidating the role of quasars in that story.”

Paintballs may deflect an incoming asteroid

Posted: October 28, 2012 by phaedrap1 in News, Science
Tags: ,
Paintballs may deflect an incoming asteroid
An artist’s rendering of the asteroid Apophis.
Image: European Space Agency
October 26, 2012

With 20 years’ notice, paint pellets could cause an asteroid to veer off course.

In the event that a giant asteroid is headed toward Earth, you’d better hope that it’s blindingly white. A pale asteroid would reflect sunlight — and over time, this bouncing of photons off its surface could create enough of a force to push the asteroid off its course.

How might one encourage such a deflection? The answer, according to an MIT graduate student: with a volley or two of space-launched paintballs.

Sung Wook Paek, a graduate student in MIT’s Department of Aeronautics and Astronautics, says if timed just right, pellets full of paint powder, launched in two rounds from a spacecraft at relatively close distance, would cover the front and back of an asteroid, more than doubling its reflectivity, or albedo. The initial force from the pellets would bump an asteroid off course; over time, the sun’s photons would deflect the asteroid even more.

Paek’s paper detailing this unconventional strategy won the 2012 Move an Asteroid Technical Paper Competition, sponsored by the United Nations’ Space Generation Advisory Council, which solicits creative solutions to space-related problems from students and young professionals. Paek presented his paper this month at the International Astronautical Congress in Naples, Italy.

The challenge put forth by this year’s U.N. competition was to identify novel solutions for safely deflecting a near-Earth object, such as an asteroid. Scientists have proposed a wide variety of methods to avoid an asteroid collision. Some proposals launch a projectile or spacecraft to collide with an incoming asteroid; the European Space Agency is currently investigating such a mission.

Other methods have included detonating a nuclear bomb near an asteroid or equipping spacecraft as “gravity tractors,” using a craft’s gravitational field to pull an asteroid off its path.

Paek’s paintball strategy builds on a solution submitted by last year’s competition winner, who proposed deflecting an asteroid with a cloud of solid pellets. Paek came up with a similar proposal, adding paint to the pellets to take advantage of solar radiation pressure — the force exerted on objects by the sun’s photons. Researchers have observed that pressure from sunlight can alter the orbits of geosynchronous satellites, while others have proposed equipping spacecraft with sails to catch solar radiation, much like a sailboat catches wind.

In his proposal, Paek used the asteroid Apophis as a theoretical test case. According to astronomical observations, this 27-gigaton rock may come close to Earth in 2029, and then again in 2036. Paek determined that five tons of paint would be required to cover the massive asteroid, which has a diameter of 1,480 feet. He used the asteroid’s period of rotation to determine the timing of pellets, launching a first round to cover the front of the asteroid, and firing a second round once the asteroid’s backside is exposed. As the pellets hit the asteroid’s surface, they would burst apart, splattering the space rock with a fine, five-micrometer-layer of paint.

From his calculations, Paek estimates that it would take up to 20 years for the cumulative effect of solar radiation pressure to successfully pull the asteroid off its Earthbound trajectory. He says launching pellets with traditional rockets may not be an ideal option, as the violent takeoff may rupture the payload. Instead, he envisions paintballs may be made in space, in ports such as the International Space Station, where a spacecraft could then pick up a couple of rounds of pellets to deliver to the asteroid.

Paek adds that paint isn’t the only substance that such pellets might hold. For instance, the capsules could be filled with aerosols that, when fired at an asteroid, “impart air drag on the incoming asteroid to slow it down,” Paek says. “Or you could just paint the asteroid so you can track it more easily with telescopes on Earth. So there are other uses for this method.”

Lindley Johnson, program manager for NASA’s Near Earth Objects Observation Program, says Paek’s proposal is “an innovative variation” on a method used by others to capitalize on solar radiation pressure. For example, MESSENGER, a spacecraft orbiting Mercury, is equipped with solar sails that propel the craft with solar radiation pressure, reducing the fuel needed to power it.

“It is very important that we develop and test a few deflection techniques sufficiently so that we know we have a viable ‘toolbox’ of deflection capabilities to implement when we inevitably discover an asteroid on an impact trajectory,” Johnson says.

William Ailor, principal engineer for Aerospace Corp. in El Segundo, Calif., adds that the potential for an asteroid collision is a long-term challenge for scientists and engineers.

“These types of analyses are really timely because this is a problem we’ll have basically forever,” Ailor says. “It’s nice that we’re getting young people thinking about it in detail, and I really applaud that.”

Jennifer Chu, MIT News Office

Split-Personality Elliptical Galaxy Holds A Hidden Spiral

Posted: October 22, 2012 by phaedrap1 in Science
Tags:

Most big galaxies fit into one of two camps: pinwheel-shaped spiral galaxies and blobby elliptical galaxies.

Spirals like the Milky Way are hip and happening places, with plenty of gas and dust to birth new stars. Ellipticals are like cosmic retirement villages, full of aging residents in the form of red giant stars.

Now, astronomers have discovered that one well-known elliptical has a split personality. Centaurus A is hiding a gassy spiral in its center.

 

 


Click on image to enlarge

M87The giant elliptical galaxy M87 shows a split personality because it hides a gaseous spiral at its core. When M87 collided with a spiral galaxy 300 million years ago, it slurped up the spiral’s gases, which formed a new spiral inside the larger galaxy. Credit: ESO
“No other elliptical galaxy is known to have spiral arms,” said lead author Daniel Espada (National Astronomical Observatory of Japan & Harvard-Smithsonian Center for Astrophysics).

“Centaurus A may be an old galaxy, but it’s still very young at heart.”

 
Centaurus A isn’t your typical elliptical to begin with. Its most striking feature is a dark dust lane across its middle – a sign that it swallowed a spiral galaxy about 300 million years ago.

Centaurus A slurped that galaxy’s gases down, forming a disk that we see nearly edge on. From our point of view, any features in that disk have been hidden by the intervening dust.

This pan video takes a close look at the peculiar galaxy Centaurus A (NGC 5128) in an image taken with by the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. With a total exposure time of more than 50 hours this is one of the most revealing views of this peculiar and spectacular object every created. Credit: ESO

 

This video zoom sequence starts with a broad view of the Milky Way. We close in on a region not far from the plane of a the galaxy and can soon see a strange fuzz with a dark band across it. This is the famous peculiar radio galaxy Centaurus A. The final view shows a new and very detailed image from the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. Credit: ESO/Nick Risinger (skysurvey.org)
To tease out the disk’s structure, Espada and his colleagues used the sharp vision of the Smithsonian’s Submillimeter Array. This radio telescope can see through dust to pick up signals from naturally occurring carbon monoxide gas.

By mapping the gas, the team unveiled two distinct spiral arms within the galaxy’s core.

These gaseous tendrils have sizes and shapes similar to spiral arms in galaxies like the Milky Way. Also like the Milky Way’s spiral arms, they are forming new generations of stars.

“Centaurus A has been given a new lease on life by that past merger,” said Espada.

Computer simulations suggest that the spiral features might endure for hundreds of millions of years to come.

Although Centaurus A is the first elliptical galaxy found to have spiral arms, it may not be the last. Since it’s only 12 million light-years away, it’s relatively nearby and easy to study. The Atacama Large Millimeter/submillimeter Array (ALMA) potentially can find more split-personality galaxies with its improved radio “vision.”

“We definitely will use ALMA to search for other objects that are similar to Centaurus A,” added Espada.

These findings were published in The Astrophysical Journal Letters and are available online.

 

MessageToEagle.com

The Watchers Tweet Tweet 41,000 years ago, a complete and rapid reversal of the geomagnetic field occurred. As a consequence, the Earth nearly completely lost its protection shield against hard cosmic rays, leading to a significantly increased radiation exposure, a new study led by Dr. Norbert Nowaczyk and Prof. Helge Arz claims. A geomagnetic reversal is a change in the Earth’s magnetic field such that the positions of magnetic north and magnetic south are interchanged. The Earth’s field has alternated between periods...

    41,000 years ago, a complete and rapid reversal of the geomagnetic field occurred. As a consequence, the Earth nearly completely lost its protection shield against hard cosmic rays, leading to a significantly increased radiation exposure, a new study led by Dr. Norbert Nowaczyk and Prof. Helge Arz claims.

    A geomagnetic reversal is a change in the Earth’s magnetic field such that the positions of magnetic north and magnetic south are interchanged. The Earth’s field has alternated between periods of normal polarity, in which the direction of the field was the same as the present direction, and reverse polarity, in which the field was the opposite. These periods are called chrons.

    Magnetic studies of the GFZ German Research Centre for Geosciences on sediment cores from the Black Sea show that during this period, during the last ice age, a compass at the Black Sea would have pointed to the south instead of north.

    Moreover, data obtained by the research team formed around GFZ researchers Dr. Norbert Nowaczyk and Prof. Helge Arz, together with additional data from other studies in the North Atlantic, the South Pacific and Hawaii, prove that this polarity reversal was a global event. Their results are published in the latest issue of the scientific journal “Earth and Planetary Science Letters”.

    What is remarkable is the speed of the reversal: “The field geometry of reversed polarity, with field lines pointing into the opposite direction when compared to today’s configuration, lasted for only about 440 years, and it was associated with a field strength that was only one quarter of today’s field,” explains Norbert Nowaczyk. “The actual polarity changes lasted only 250 years. In terms of geological time scales, that is very fast.” During this period, the field was even weaker, with only 5% of today’s field strength. As a consequence, the Earth nearly completely lost its protection shield against hard cosmic rays, leading to a significantly increased radiation exposure.

    Abrupt climate changes and a super volcano

    Besides giving evidence for a geomagnetic field reversal 41,000 years ago, the geoscientists from Potsdam discovered numerous abrupt climate changes during the last ice age in the analysed cores from the Black Sea, as it was already known from the Greenland ice cores. This ultimately allowed a high precision synchronisation of the two data records from the Black Sea and Greenland. The largest volcanic eruption on the Northern hemisphere in the past 100 000 years, namely the eruption of the super volcano 39400 years ago in the area of today’s Phlegraean Fields near Naples, Italy, is also documented within the studied sediments from the Black Sea. The ashes of this eruption, during which about 350 cubic kilometers of rock and lava were ejected, were distributed over the entire eastern Mediterranean and up to central Russia.

    These three extreme scenarios, a short and fast reversal of the Earth’s magnetic field, short-term climate variability of the last ice age and the volcanic eruption in Italy, have been investigated for the first time in a single geological archive and placed in precise chronological order.

    (Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences. “Ice age polarity reversal was global event: Extremely brief reversal of geomagnetic field, climate variability, and super volcano.” ScienceDaily, 16 Oct. 2012. Web. 19 Oct. 2012.)

    NASA claims geomagnetic reversals are the rule, not the exception

    Above: Supercomputer models of Earth’s magnetic field. On the left is a normal dipolar magnetic field, typical of the long years between polarity reversals. On the right is the sort of complicated magnetic field Earth has during the upheaval of a reversal.

    In November 2011, NASA published an interesting article claiming this kind of geomagnetic reversals occur as a rule, not an exception. The N-S markings of a compass would be 180 degrees wrong if the polarity of today’s magnetic field were reversed. Many doomsday theorists have tried to take this natural geological occurrence and suggest it could lead to Earth’s destruction. But would there be any dramatic effects? The answer, from the geologic and fossil records we have from hundreds of past magnetic polarity reversals, seems to be ‘no.’

    The following is a part of above mentioned article with its headline as they wrote it:

    2012: Magnetic pole reversal happens all the (geologic) time

    Earth’s polarity is not a constant. Unlike a classic bar magnet, or the decorative magnets on your refrigerator, the matter governing Earth’s magnetic field moves around. Geophysicists are pretty sure that the reason Earth has a magnetic field is because its solid iron core is surrounded by a fluid ocean of hot, liquid metal. This process can also be modeled with supercomputers. Ours is, without hyperbole, a dynamic planet. The flow of liquid iron in Earth’s core creates electric currents, which in turn create the magnetic field. So while parts of Earth’s outer core are too deep for scientists to measure directly, we can infer movement in the core by observing changes in the magnetic field. The magnetic north pole has been creeping northward – by more than 600 miles (1,100 km) – since the early 19th century, when explorers first located it precisely. It is moving faster now, actually, as scientists estimate the pole is migrating northward about 40 miles per year, as opposed to about 10 miles per year in the early 20th century.

    Another doomsday hypothesis about a geomagnetic flip plays up fears about incoming solar activity. This suggestion mistakenly assumes that a pole reversal would momentarily leave Earth without the magnetic field that protects us from solar flares and coronal mass ejections from the sun. But, while Earth’s magnetic field can indeed weaken and strengthen over time, there is no indication that it has ever disappeared completely. A weaker field would certainly lead to a small increase in solar radiation on Earth – as well as a beautiful display of aurora at lower latitudes — but nothing deadly. Moreover, even with a weakened magnetic field, Earth’s thick atmosphere also offers protection against the sun’s incoming particles.

    The science shows that magnetic pole reversal is – in terms of geologic time scales – a common occurrence that happens gradually over millennia. While the conditions that cause polarity reversals are not entirely predictable – the north pole’s movement could subtly change direction, for instance – there is nothing in the millions of years of geologic record to suggest that any of the 2012 doomsday scenarios connected to a pole reversal should be taken seriously. A reversal might, however, be good business for magnetic compass manufacturers.

    Sources: Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences, sciencedaily.com, nasa.gov

    About the Helmholtz Centre Potsdam: The Helmholtz Association is dedicated to pursuing the long-term research goals of state and society, and to maintaining and improving the livelihoods of the population. In order to do this, the Helmholtz Association carries out top-level research to identify and explore the major challenges facing society, science and the economy. Its work is divided into six strategic research fields: Energy; Earth and Environment; Health; Key Technologies; Structure of Matter; and Aeronautics, Space and Transport. The Helmholtz Association brings together 18 scientific-technical and biological-medical research centres. With some 32,698 employees and an annual budget of approximately €3.4 billion, the Helmholtz Association is Germany’s largest scientific organisation. Its work follows in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894).

    Featured image: Schematic illustration of Earth’s magnetic field. Credit/Copyright: Peter Reid, The University of Edinburgh

    By Adonai/The Watchers

    • Images are most detailed ever taken of the planet
    • Planet was initially described as ‘notoriously bland’ by researchers
    • Scientists now believe weather patterns are constantly changing on the surface

    In 1986, when Voyager swept past Uranus, the probe’s portraits of the planet were ‘notoriously bland,’ disappointing scientists, yielding few new details of the planet and its atmosphere, and giving it a reputation as a bore of the solar system.

    However, researchers today revealed new images that reveal the planet is actually home to torrid and bizarre weather patterns unseen on any other planet.

    Researchers used a new technique at the Keck Observatory to reveal in incredible detail the bizarre weather of the seventh planet from the sun.

    The sharpest, most detailed picture of Uranus. The north pole of Uranus (to the right in the picture) is characterized by a swarm of storm-like featuresThe sharpest, most detailed picture of Uranus. The north pole of Uranus (to the right in the picture) is characterized by a swarm of storm-like features

    THE ‘NOTORIOUSLY BLAND’ PLANET

    Uranus is the seventh planet from the Sun, and is named after the ancient Greek deity of the sky Uranus (Ancient Greek: Οὐρανός), the father of Cronus (Saturn) and grandfather of Zeus (Jupiter).

    Though it is visible to the naked eye like the five classical planets, it was never recognized as a planet by ancient observers because of its dimness and slow orbit.

    It is similar in composition to Neptune, and both are of different chemical composition than the larger gas giants, Jupiter and Saturn.

    Astronomers sometimes place them in a separate category called ‘ice giants’.

    Like the other giant planets, Uranus has a ring system, a magnetosphere, and numerous moons – but is unique because it is tilted sideways.

    The images reveal the planet’s deep blue-green atmosphere is thick with hydrogen, helium and methane, Uranus’s primary condensable gas.

    Winds blow mainly east to west at speeds up to 560 miles per hour, in spite of the small amounts of energy available to drive them.

    Researchers say the atmosphere is almost equal to Neptune’s as the coldest in our solar system with cloud-top temperatures in the minus 360-degree Fahrenheit range, cold enough to freeze methane.

    ‘My first reaction to these images was ‘wow’ and then my second reaction was WOW,’ says AURA’s Heidi Hammel, a co-investigator on the new observations and an expert on the atmospheres of the solar system’s outer planets.

    ‘These images reveal an astonishing amount of complexity in Uranus’s atmosphere.

    ‘We knew the planet was active, but until now much of the activity was masked by noise in our data.’

    Large weather systems, which are probably much less violent than the storms we know on Earth, behave in bizarre ways on Uranus, said Larry Sromovsky, a University of Wisconsin-Madison planetary scientist who led the new study using the Keck II telescope.

    The scalloped band of clouds near the planet’s equator may indicate atmospheric instability or wind shear: ‘This is new and we don’t fully understand what it means.

    ‘We haven’t seen it anywhere else on Uranus,’ said Sromovsky.

    ‘Some of these weather systems stay at fixed latitudes and undergo large variations in activity.

    ‘Others are seen to drift toward the planet’s equator while undergoing great changes in size and shape.

    ‘Better measures of the wind fields that surround these massive weather systems are the key to unraveling their mysteries.’

    The team believe the primary driving mechanism for the strange weather must be solar energy because there is no detectable internal energy source.

    ‘But the sun is 900 times weaker there than on Earth because it is 30 times further from the sun, so you don’t have the same intensity of solar energy driving the system,’ said Sromovsky.

    ‘Thus the atmosphere of Uranus must operate as a very efficient machine with very little dissipation.

    Previous images of Uranus, such as this one taken in January 2004, failed to spot the weather conditions.Previous images of Uranus, such as this one taken in January 2004, failed to spot the weather conditions.

    ‘Yet the weather variations we see seem to defy that requirement.’

    The new Keck II pictures of the planet, according to Sromovsky, are the ‘most richly detailed views of Uranus yet obtained by any instrument on any observatory.

    ‘No other telescope could come close to producing this result.’

    The images were released in Renoat a meeting of the American Astronomical Society’s Division of Planetary Sciences.

    The team used used Keck II, located on the summit of Hawaii’s 14,000-foot extinct volcano Mauna Kea, to capture a series of images that, when combined, help increase the signal to noise ratio and thus tease out weather features that are otherwise obscured.

    In two nights of observing under superb conditions, Sromovsky’s group was able to obtain exposures of the planet that provide a clear view of the planet’s cloudy features, including several new to science.

    The group used two different filters in an effort to characterize cloud features at different altitudes.

    Two telescopes at the W.M. Keck Observatory on Mauna Kea on the Big Island of Hawaii which were used to capture the new imagesTwo telescopes at the W.M. Keck Observatory on Mauna Kea on the Big Island of Hawaii which were used to capture the new images

    ‘The main objective was to find a larger number of cloud features by detecting those that were previously too subtle to be seen, so we could better define atmospheric motions,’

    New features found by the Wisconsin group include a scalloped band of clouds just south of Uranus’s equator and a swarm of small convective features in the north polar regions of the planet, features that have never been seen in the southern polar regions.

    ‘This is a very asymmetric situation: There is certainly something different going on in those two polar regions.’

    One possible explanation, is that methane is pushed north by an atmospheric conveyor belt toward the pole where it wells up to form the convective features observed by Sromovsky’s group.

    ‘Perhaps we will also see a vortex at Uranus’s pole when it comes into view,’ the researchers said.

    The phenomena may be seasonal, Sromovsky notes, but the group has so far been unable to establish a clear seasonal trend in the winds of Uranus.

    ‘Uranus is changing,’ he says. ‘We don’t expect things at the north pole to stay the way they are now.

    By Mark Prigg

    Spectacular Meteor Sparks Fireball Over California

    Posted: October 18, 2012 by phaedrap1 in News, Science
    Tags: ,
    Fireball Over Belmont, CA
    Wes Jones caught the fireball over Belmont, CA, at 7:44 PM PDT, Oct. 17, 2012, using the camera at http://astrobytes.net/AllSky3.html.
    CREDIT: Wes Jones

    A spectacular meteor lit up the sky over California Wednesday night (Oct. 17) just days before a highly anticipated meteor shower hits its peak this weekend.

    The meteor put on a dazzling display over Northern California when it streaked across the sky at 7:44 p.m. PDT (0244 GMT), according to scientists at NASA’s Ames Research Center in Moffett Field. The subsequent fireball and sonic boom triggered a flood of reports by witnesses to local news stations and authorities, with accounts coming in from across San Francisco and the Bay Area, according to ABC’s KGO-TV news station.

    “At 7:44:44 pm PDT this evening, a bright fireball was seen  in the San Francisco Bay Area,” scientists with Ames’ Cameras for Allsky Meteor Surveillance (CAMS) wrote in an update. The project is led by meteor expert Peter Jenniskens of the SETI (Search for Extraterrestrial Intelligence) Institute. “We are checking our CAMS camera results to see if we have a track. Biggest question at the moment is whether this ended over land or ocean.”

     

    The celestial fireworks came just days ahead of this weekend’s Orionid meteor shower peak, which occurs overnight on Oct. 20 and 21. The meteor shower is created by bits of the famed Halley’s Comet as they hit Earth’s atmosphere and flare up in fiery display.

    October 2012 Orionid Meteor Shower
    The Orionids are remnants of Halley’s Comet scattered along its orbit, one of the finest meteor showers in the year. The meteors appear to radiate from a point just between Orion’s club and the Gemini twins’ feet, but may be seen anywhere in the sky.
    CREDIT: Starry Night Software

    NASA meteor expert Bill Cooke at the agency’s Marshall Space Flight Center in Huntsville, Ala., has said the 2012 Orionid meteor shower should create dozens of meteors an hour, weather permitting. Because the moon is just a few days past its dark, “new” phase, it won’t interfere with the weekend “shooting stars” show.

    The Orionid meteor shower is one of two meteor displays created by Halley’s Comet, which makes one orbit around the sun every 76 years. The other is the Eta Aquarid meteor shower, which occurs in May. The two meteor showers are created when the Earth passes through streams of dust cast off from Halley’s Comet.

    Editor’s Note: If you snapped a photo of Wednesday night’s dazzling meteor and would like to share it with SPACE.com, please send images, comments and your location info to managing Editor Tariq Malik at: tmalik@space.com.

    You can follow SPACE.com Managing Editor Tariq Malik on Twitter @tariqjmalik and SPACE.com on Twitter @Spacedotcom. We’re also on Facebook & Google+

     

    Huge Moon-Forming Collision Theory Gets New Spin

    Posted: October 18, 2012 by phaedrap1 in News, Science
    Tags: ,
    Moon Born in Violence
    This artist’s conception of a planetary smashup whose debris was spotted by NASA’s Spitzer Space Telescope three years ago gives an impression of the carnage that would have been wrecked when a similar impact created Earth’s Moon. A team at Washington University in St. Louis has uncovered evidence of this impact that scientists have been trying to find for more than 30 years. Image released Oct. 17, 2012.
    CREDIT: NASA/JPL-Caltech

    The moon did indeed coalesce out of tiny bits of pulverized planet blasted into space by a catastrophic collision 4.5 billion years ago, two new studies suggest.

    The new research potentially plugs a big hole in the giant impact theory, long the leading explanation for the moon’s formation. Previous versions of the theory held that the moon formed primarily from pieces of a mysterious Mars-size body that slammed into a proto-Earth — but that presented a problem, because scientists know that the moon and Earth are made of the same stuff.

    The two studies both explain how Earth and the moon came to be geochemical twins. However, they offer differing versions of the enormous smashup that apparently created Earth’s natural satellite, giving scientists plenty to chew on going forward.

    A fast-spinning Earth

    One of the studies — by Matija Cuk of the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, Calif., and Sarah Stewart of Harvard — suggests the answer lies in Earth’s rotation rate.

    If Earth’s day had been just two to three hours long at the time of the impact, Cuk and Stewart calculate, the planet could well have thrown off enough material to form the moon (which is 1.2 percent as massive as Earth).

    This rotational speed might sound incredible, and indeed it’s close to the threshold beyond which the planet would begin to fly apart. But researchers say the early solar system was a “shooting gallery” marked by many large impacts, which could have spun planets up to enormous speeds.

    Cuk and Stewart’s study, which appears online today (Oct. 17) in the journal Science, also provides a mechanism by which Earth’s rotation rate could have slowed over time.

    After the collision, a gravitational interaction between Earth’s orbit around the sun and the moon’s orbit around Earth could have put the brakes on the planet’s super-spin, eventually producing a 24-hour day, the scientists determined.

    A Massive Collision Creates the Moon
    Simulation of an off-center, low-velocity collision between two protoplanets containing 45 percent and 55 percent of Earth’s mass. Color scales with particle temperature in kelvin, with blue-to-red indicating temperatures from 2,000 K to in excess of 6,440 K. After the initial impact, the protoplanets re-collide, merge and form a rapidly spinning Earth-mass planet surrounded by an iron-poor protolunar disk containing about 3 lunar masses. The composition of the disk and the final planet’s mantle differ by less than 1 percent.
    CREDIT: Southwest Research Institute

    A bigger impactor

    Cuk and Stewart’s version of the cosmic smashup posits a roughly Mars-size impactor — a body with 5 percent to 10 percent the mass of Earth. However, the other new study — being published in the same issue of Science today — envisions a collision between two planets in the same weight class.

    “In this impact, the impactor and the target each contain about 50 percent of the [present] Earth’s mass,” Robin Canup, of the Southwest Research Institute in Boulder, Colo., told SPACE.com via email.

    “This type of impact has not been advocated for the Earth-moon before (although a similar type of collision has been invoked for the origin of the Pluto-Charon pair),” Canup added, referring to the largest moon of Pluto.

    In her computer models, the symmetry of this collision caused the resulting moon-forming debris disk to be nearly identical in composition to the mantle of the newly enlarged Earth.

    Canup’s models further predict that such an impact would significantly increase Earth’s rotational speed. But that may not be a big issue, since Cuk and Stewart’s work explains how Earth’s spin could have slowed over time.

    A third study, published today in the journal Nature, determined that huge amounts of water boiled away during the moon’s birth. The finding, made by examining moon rocks brought back to Earth by Apollo astronauts, further bolsters the broad outlines of the giant impact theory.

    Though the gigantic smashup occurred 4.5 billion years ago, scientists may one day be able to piece together in detail how it all went down, Canup said.

    “Models of terrestrial planet assembly should be able to evaluate the relative probability of, e.g., the collision I advocate vs. the one proposed by Cuk and Stewart,” she said.

     

    by Mike Wall, SPACE.com Senior Writer

    Date: 17 October 2012

    Russia’s space agency wants to send a mission to Apophis, the notorious asteroid which may change its course and eventually collide with Earth. It will plant a radio beacon, which will help track the celestial body and assess the risks it poses.

    ­The 300-meter-wide asteroid first made headlines in 2004, when NASA reported that it has 1 chance in 223 of impacting on our planet in 2029. It was even named after the Ancient Egyptian evil god, archenemy of the sun god Ra.

    But additional observations proved that it will pass by at the small, but safe, distance of some 36,000 kilometers from Earth. The close approach however may result in an unpredictable gravitational pull on Apophis, which would change its course and pose a danger in 2036, when it comes back.

    To better assess the risks it poses to the civilization the Roscosmos plans a robotic mission to the asteroid, chief Vladimir Popovkin announced on Monday.

    The plan is “to land a module on the surface of Apophis and set up a radio beacon there, which will work after the spaceship’s lifetime expires,” he said at the Space Research Institute in Moscow.

    The beacon signal will allow astronomers to better calculate Apophis’ movement and the effect of the 2029 Earth flyby. The mission would not be launched before 2020.

    Popovkin, who was speaking at a solar system exploration conference, outlined other mid-term plans Roscosmos has. These include a Venus orbiter between 2020 and 2025, which will study the planet’s hot and dense atmosphere. The mission may include a descending probe, although due to the harsh environment it would only work for about one day on the surface.

    Another target is Jupiter’s moon Ganymede. Roscosmos plans to send a spacecraft there in 2022 and is currently negotiating with its European counterpart ESA, which has a similar project, over a possible closer collaboration.

    Russia also plans a new Mars mission. Popovkin said launching such a spacecraft is no less important after the embarrassing failure of Fobos-Grunt in November 2011. Now engineers will be able to learn from the mistakes of the original attempt to reach the Martian moon.

    A more immediate plan is the Luna Glob mission to the Moon scheduled for late 2015. It would include returning a soil sample to Earth and studying it from an orbiter, which would change its altitude from the initial 100 kilometers down to 50 kilometers and later to 500 kilometers. The soil would later be studied for possible extraction of water from it.

    “We will allocate our main effort and majority of resources to the moon,”
    Popovkin said.

    RT Published: 08 October, 2012, 16:46