Monday, April 30, 2007

Galileo Constellation

Artist's impression of Galileo satellite constellation. Credits: ESA-J. Huart

Call for ideas in satellite navigation - Galileo Masters 2007

When fully deployed in 2011-2012, Galileo, Europe’s own global navigation satellite system, will be the world’s first completely civilian positioning system. Galileo will provide a highly accurate, guaranteed global positioning service and will be inter-operable with GPS and GLONASS, the two other global satellite navigation systems. Galileo is a joint initiative between ESA and the European Commission.

The fully deployed Galileo system will consist of 30 satellites, 27 operational plus 3 active spares, positioned in three circular Medium Earth Orbit (MEO) planes at 23 222 km altitude above the Earth.
A step closer to a European Space Policy
Track ESA spacecraft online in Real Time

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Saturday, April 28, 2007

Solar Storm Cycle

The next 11-year cycle of solar storms will most likely start next March and peak in late 2011 or mid-2012—up to a year later than expected—according to a forecast issued by the NOAA Space Environment Center in coordination with an international panel of solar experts. The NOAA Space Environment Center led the prediction panel and issued the forecast at its annual Space Weather Workshop in Boulder, Colo.

Expected to start last fall, the delayed onset of Solar Cycle 24 stymied the panel and left them evenly split on whether a weak or strong period of solar storms lies ahead, but neither group predicts a record-breaker.

During an active solar period, violent eruptions occur more often on the sun. Solar flares and vast explosions, known as coronal mass ejections, shoot energetic photons and highly charged matter toward Earth, jolting the planet's ionosphere and geomagnetic field, potentially affecting power grids, critical military and airline communications, satellites, Global Positioning System (GPS) signals, and even threatening astronauts with harmful radiation. These same storms illuminate night skies with brilliant sheets of red and green known as auroras, or the northern or southern lights.

Next Solar Storm Cycle Will Likely Start Next March
Read more from NOAA Press Release.

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Thursday, April 26, 2007

Catastrophes in the Solar System

Earth sits between two worlds that have been devastated by climate catastrophes. In the effort to combat global warming, our neighbours can provide valuable insights into the way climate catastrophes affect planets.

Modelling Earth’s climate to predict its future has assumed tremendous importance in the light of mankind’s influence on the atmosphere. The climate of our two neighbours is in stark contrast to that of our home planet, making data from ESA’s Venus Express and Mars Express invaluable to climate scientists.
Venus is a cloudy inferno whilst Mars is a frigid desert. As current concerns about global warming have now achieved widespread acceptance, pressure has increased on scientists to propose solutions.

The atmosphere of Venus is much thicker than Earth’s. Nevertheless, current climate models can reproduce its present temperature structure well. Now planetary scientists want to turn the clock back to understand why and how Venus changed from its former Earth-like conditions into the inferno of today.

They believe that the planet experienced a runaway greenhouse effect as the Sun gradually heated up. Astronomers believe that the young Sun was dimmer than the present-day Sun by 30 percent. Over the last 4 thousand million years, it has gradually brightened. During this increase, Venus’s surface water evaporated and entered the atmosphere.

“Water vapour is a powerful greenhouse gas and it caused the planet to heat-up even more. This is turn caused more water to evaporate and led to a powerful positive feedback response known as the runaway greenhouse effect.”

As Earth warms in response to manmade pollution, it risks the same fate. Reconstructing the climate of the past on Venus can give scientists a better understanding of how close our planet is to such a catastrophe. However, determining when Venus passed the point of no return is not easy. That’s where ESA’s Venus Express comes in.

The spacecraft is in orbit around Venus collecting data that will help unlock the planet’s past. Venus is losing gas from its atmosphere, so Venus Express is measuring the rate of this loss and the composition of the gas being lost. It also watches the movement of clouds in the planet’s atmosphere. This reveals the way Venus responds to the absorption of sunlight, because the energy from the Sun provides the power that allows the atmosphere to move.

In addition, Venus Express is charting the amount and location of sulphur dioxide in the planet’s atmosphere. Sulphur dioxide is a greenhouse gas and is released by volcanoes on Venus.

What happened on these two worlds is very different but either would be equally disastrous for Earth. We are banking on our ability to accurately predict Earth’s future climate.

Climate catastrophes in the Solar System ESA press release 26 April 2007
Gliese and Earth-like Worlds from Centauri Dreams
NASA's AIM Mission Soars To The Edge Of Space
Satellites Play Vital Role In Understanding The Carbon Cycle

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Wednesday, April 25, 2007

Rosette Nebula

In a new study from NASA's Spitzer Space Telescope, scientists report the first maps of so-called planetary "danger zones." These are areas where winds and radiation from super hot stars can strip other young, cooler stars like our sun of their planet-forming materials. The results show that cooler stars are safe as long as they lie beyond about 1.6 light-years, or nearly 10 trillion miles, of any hot stars. But cooler stars inside the zone are likely to see their potential planets boiled off into space.

Planets are born out of a flat disk of gas and dust, called a protoplanetary disk, that swirls around a young star. They are believed to clump together out of the disk over millions of years, growing in size like dust bunnies as they sweep through the dust.
Previous studies revealed that these protoplanetary disks can be destroyed by the most massive, hottest type of star in the universe, called an O-star, over a period of about a million years. Ultraviolet radiation from an O-star heats and evaporates the dust and gas in the disk, then winds from the star blow the material away.

Last year, Balog and his team used Spitzer to capture a stunning picture of this "photoevaporation" process at work.

The team's new study is the first systematic survey for disks in and around the danger zone, or "blast radius" of an O-star. They used Spitzer's heat-seeking infrared eyes to look for disks around 1,000 stars in the Rosette Nebula, a turbulent star-forming region 5,200 light-years away in the constellation Monoceros. The stars range between one-tenth and five times the mass of the sun and are between 2 and 3 million years old. They are all near at least one of the region's massive O-stars.

The observations revealed that, beyond 10 trillion miles of an O-star, about 45 percent of the stars had disks -- about the same amount as there were in safer neighborhoods free of O-stars. Within this distance, only 27 percent of the stars had disks, with fewer and fewer disks spotted around stars closest to the O-star. In other words, an O-star's danger zone is a sphere whose damaging effects are worst at the core. For reference, our sun's closest star, a small star called Proxima Centauri, is nearly 30 trillion miles away.

"Stars move around all the time, so if one wanders into the danger zone and stays for too long, it will probably never be able to form planets," said Zoltan Balog of the University of Arizona, Tucson, lead author of the new report, appearing May 20 in the Astrophysical Journal.

Astronomers Map Out Planetary Danger Zone
Spitzer/Caltech press release 18.04.07
Gravitational Waves by Daniel Holz @ Cosmic Variance
String Theory in 2 minutes via Lubos Motl @ Reference Frame
Cosmologically speaking, Diamonds may actually be forever

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Tuesday, April 24, 2007

Star Birth In The Extreme

Mosaic of the Carina Nebula - Click Image to Enlarge

This immense nebula contains a dozen or more brilliant stars that are estimated to be at least 50 to 100 times the mass of our Sun. The most rich and extensive one is the variable star eta Carinae, seen at far left. Eta Carinae is in the final stages of its brief eruptive lifespan, as shown by two billowing lobes of gas and dust that foretell its upcoming explosion as a titanic supernova.

The fireworks in the Carina region started three million years ago when the nebula's first generation of newborn stars condensed and ignited in the middle of a huge cloud of cold molecular hydrogen. Radiation from these stars carved out an expanding bubble of hot gas - a cavity. The island-like clumps of dark clouds scattered across the nebula are nodules of dust and gas that have so far resisted being eaten away by photoionisation by the stellar radiation.

The hurricane-strength blast of stellar winds and blistering ultraviolet radiation within the cavity is now compressing the surrounding walls of cold hydrogen. This is triggering a second stage of new star formation.

Our Sun and Solar System may have been born inside such a cosmic furnace 4600 million years ago. In looking at the Carina Nebula we are seeing star formation as it commonly occurs along the dense spiral arms of a galaxy.

This immense nebula is an estimated 7500 light-years away in the southern constellation Carina, the Keel of the old southern constellation Argo Navis, the ship of Jason and the Argonauts from Greek mythology.

Credit: NASA, ESA, N. Smith (University of California, Berkeley),
and The Hubble Heritage Team (STScI/AURA)

The Carina Nebula: Star Birth in the Extreme from Hubblesite
Mapping The Invisible from Science Daily
Star-Forming Region in the Carina Nebula
Forming Galaxies Captured In The Young Universe

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Monday, April 23, 2007



The two spacecraft that make up the NASA STEREO mission were launched last October. One probe is now travelling in an orbit ahead of the Earth while the other lags behind. Together the probes are imaging the Sun in 3D.

They also have a unique perspective - they can view the space between the Sun and the Earth (the so-called Earth-Sun line), giving scientists their first views of this region of space.

[+/-] Click here to expand

The Rutherford Appleton Laboratory (RAL) in Oxfordshire and the University of Birmingham led an international effort to develop two identical Heliospheric Imager (HI) instruments. One HI is mounted on each of the two spacecraft so astronomers can watch the Earth-Sun line. In particular, this view gives scientists a ringside seat when giant clouds of material (Coronal Mass Ejections or CMEs) travel from the Sun to the Earth.

CMEs can be made up of more than 1000 million tonnes of charged particles and travel at up to 1000 km per second. When a CME reaches the Earth it can have dramatic effects; compressing the terrestrial magnetic field, generating displays of the northern lights, disrupting radio communications, overloading power grids and damaging satellites.

Images and animation available @

Heavenly Music
from The Royal Astronomical Society

Astronomers have found that the atmosphere of the Sun plays a kind of heavenly music. The magnetic field in the outer regions (the corona) of our nearest star forms loops that carry waves and behave rather like a musical instrument.

In recent years scientists have worked hard to better explain and predict the dynamic behaviour of the Sun. For example, missions like STEREO and Hinode watch as material is ejected towards the Earth, events which are controlled by the solar magnetic field.

Scientists combined observations with new theoretical models to study the magnetic sound waves that are set up along loops in the corona. “These loops can be up to 100 million kilometres long and guide waves and oscillations in a similar way to a pipe organ.”

The acoustic waves can be extremely powerful and reach amplitudes of tens of kilometres per second. “The waves are often generated at the base of the magnetic pipes by enormous explosions known as micro-flares. These release energy equivalent to millions of hydrogen bombs. After each micro-flare, sound booms are rapidly excited inside the magnetic pipes before decaying in less than an hour and dissipating in the very hot solar corona.”


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Veritas & Gamma Rays

The four telescopes of the VERITAS system at the Fred Lawrence Whipple Observatory in Arizona create the northern hemisphere's most sensitive instrument for finding gamma rays from space. Photo by S. Criswell, VERITAS Project.

The $20 million VERITAS telescope system - that's the Very Energetic Radiation Imaging Telescope Array System - at the Fred Lawrence Whipple Observatory south of Tucson, is made of four reflectors 12 meters across that look like satellite dishes. The reflectors are covered with mirrors that direct light into cameras attached to the front of each dish. Each camera is about 7 feet across and contains 500 tube-shaped photon detectors or pixels.

Each of the four VERITAS cameras created by Iowa State researchers contains 500 photon detectors that can see particle showers created by gamma rays hitting the earth's atmosphere.
Photo contributed by Frank Krennrich

VERITAS is the northern hemisphere's most sensitive instrument for finding that high energy electromagnetic radiation. And gamma rays do have lots of energy: the energy of visible light is one electron volt; gamma rays have energies of 1 million to 1 trillion electron volts.

Even with all that energy, the rays can't penetrate the earth's atmosphere. But when they hit the atmosphere they create showers of electrons and positrons that create a blue light known as Cerenkov radiation. The showers move very fast. And they're not very bright.

So it takes a powerful instrument to find them. The astronomers say VERITAS is proving to be as sensitive as they expected.

Astrophysicists now know that gamma rays are produced by supermassive black holes, supernova remnants, pulsars, gamma ray bursts and other space objects.

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Saturday, April 21, 2007

The Universe in a flower

Blue_Morning_Glory - Click on Image to Enlarge
Image Credit copyright @ Xfg21042007/C5050Z

Like the Morning Glory in the picture, it is said the Universe started in an instant from a single node. In Time, Space (space-time) grew and unfolded outward like the funnel shape of the petals to arrive at where we are today. Sitting comfortably close to the fully open outer rim of the flower or Universe.

The light from the centre in the flower is pure white, the purples and blues are those wavelengths which are reflected, all other photons wavelengths and colours are trapped by the flower and held.

If we look at the body of the flower we could say the petals are like the sea of gravity or Space on which matter surfs and conglomerates into galaxies, and like droplets of rain water resting on the flower, which form into multiple shape and size bubbles, and by surface tension are bound.

As we reach the outer rim of the flower or Universe we are told, there, is to be found a cosmic event horizon or periphery. This of course we assume or perceive to be the boundary of the observable universe as it has come to be known.

While I was observing the flower, I couldn't fail to notice
the ant (and the bee) walking along the flower, walk right over the edge to the other side of the flower's boundary or periphery.

For you see, every flower, funnel shaped conical or pyramidal has a membrane or wall, which means it has an inner and outer wall. But of course to us sitting on one of these droplets in the inner wall of the flower Universe, the outside wall is hidden and as you can see, we cannot see beyong the periphery.

Fortunately for us all, the universe lasts a lot longer than the Morning Glory, which in all its majesty is here only for a day and its beauty gone in less than an hour shortly after the last sunray.

The flower typically lasts for a single morning and dies in the afternoon. New flowers bloom each day. The flowers usually start to fade a couple of hours before the petals start showing visible curling. They prefer full sun throughout the day.

[+/-] Click here to expand

Morning glory is a common name for over a thousand species of flowering plants in the family the Convolvulaceae, belonging to the following genera:
As the name implies, morning glory flowers, which are funnel-shaped, open at morning time, allowing them to be pollinated by hummingbirds, butterflies, bees and other daytime insects and birds, as well as Hawkmoth at dusk for longer blooming variants. The flower typically lasts for a single morning and dies in the afternoon. New flowers bloom each day. The flowers usually start to fade a couple of hours before the petals start showing visible curling. They prefer full sun throughout the day, and mesic soils. In cultivation, most are treated as perennial plants in tropical areas, and as annual plants in colder climates, but some species tolerate winter cold.

Morning glory is also called asagao (in Japanese, a compound of 朝 asa "morning" and 顔 kao "face"). A rare brownish-coloured variant known as Danjuro is very popular. It was first known in China for its medicinal uses, due to the laxative properties of its seeds. It was introduced to the Japanese in the 9th century, and they were first to cultivate it as an ornament. During the Edo Period, it became a very popular ornamental flower. Aztec priests in Mexico were also known to use the plant's hallucinogenic properties to commune with their gods (see Rivea corymbosa).

Ancient Mesoamerican civilizations used the morning glory species Ipomoea alba to convert the latex from the Castilla elastica tree and also the guayule plant to produce bouncing rubber balls. The sulfur in the morning glory's juice served to vulcanize the rubber, a process pre-dating Charles Goodyear's discovery by at least 3,000 years.

Because of their fast growth, twining habit, attractive flowers, and tolerance for poor, dry soils, some morning glories are excellent vines for creating summer shade on building walls when trellised, thus keeping the building cooler and reducing air conditioning costs.

In some places such as Australian bushland morning glories develop thick roots and tend to grow in dense thickets. They can quickly spread by way of long creeping stems. By crowding out, blanketing and smothering other plants, morning glory has turned into a serious invasive weed problem.

Ipomoea aquatica, known as water spinach, water morning-glory, water convolvulus or swamp cabbage, is popularly used as a green vegetable especially in East and Southeast Asian cuisines.

The seeds of many species of morning glory contain d-lysergic acid amide, ergoline alkaloids better known as LSA. Seeds of I. tricolor and I. corymbosa (syn. R. corymbosa) are used as hallucinogens. They are about 5% to 10% as potent as LSD. Users also report the overall experience and some of the effects to be rather similar to those of LSD. However, caution must be taken as some commercial seed producers protect their seeds with a chemical that may cause vomiting, nausea and abdominal pain if the seeds are eaten.

So enjoy Today and Every Day!
Here's wishing you All a fine Earth Day this Sun day.
Radio Active Brown Dwarves are new class of Pulsar
Astronomers Make Detailed Image Of Giant Stellar Nursery
XMM-Newton Pinpoints Intergalactic Gas & Quasar Bubbles

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Friday, April 20, 2007

Scorching Hot O Stars

Image credit: NASA/JPL-Caltech

Astronomers Map Out Planetary Danger Zone
The further on the edge, the hotter the intensity. Cooler stars like our sun live in the danger zones around scorching hot stars, called O-stars. The closer a young, maverick star happens to be to a super hot O-star, the more likely its burgeoning planets will be blasted into space.

This movie animation illustrates how the process works. Showing an O-star (top right in the image above) in a murky star-forming region. It then pans out to show a young, cooler star and its swirling disk of planet-forming material. Disks like this one, called protoplanetary disks, are where planets are born. Gas and dust in a disk clumps together into tiny balls that sweep through the material, growing in size to eventually become full-grown planets.

The young star happens to lie within the "danger zone" around the O-star, which means that it is too close to the hot star to keep its disk. Radiation and winds from the O-star boil and blow away the material, respectively. This process, called photoevaporation, is sped up here but takes anywhere from 100,000 to about 1,000,000 years. Without a disk, the young star will not be able to produce planets.

Our own sun and its suite of planets might have grown up on the edge of an O-star's danger zone before migrating to its current, spacious home. However, we know that our young sun didn't linger for too long in any hazardous territory, or our planets, and life, wouldn't be here today.

NASA's Spitzer Space Telescope surveyed the danger zones around five O-stars in the Rosette nebula. It was able to determine that the zones are spheres with a radius of approximately 1.6 light-years, or 10 trillion miles.

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Wednesday, April 18, 2007

Dying Star Whirlpools

The central star of Sharpless 2-188 is 850 light years away and it is travelling at 125 kilometres per second across the sky.

Observations show a strong brightening in the direction in which the star is moving and faint material stretching away in the opposite direction.

The bright structures in the arc observed ahead of Sharpless 2-188 are the bowshock instabilities revealed in his simulations, which will form whirlpools as they spiral past the star downstream to the tail.

These vortices can improve the mixing of the stellar material back into interstellar space, benefiting the next cycle of star formation. The turbulent whirlpools have an inherent spin, or angular momentum, which is an essential ingredient for the formation of the next generation of stars." said Dr Wareing who developed the computer model during his PhD and is now using it to understand the fate of our Sun.

Dying stars eject both gas and dust into space. The dust will coalesce into planets around later generations of stars. The gas contains carbon, necessary for life and produced inside stars. How the carbon, other gas and dust are ejected from the dying star is not well understood. The whirlpools in space can play an important role in mixing these essential ingredients into the interstellar gas from which further stars and planets will form.

(Image credit: N Wright, University College London)
A combined image showing the bright regions and the faint regions behind the bright arc
Dying Sun-like Stars leave Whirlpools in their Wake
Red Supergiant Cauldrons let off Steam from SciTech
Unsolved problems in Stellar Physics Institute of Astronomy
Molecular Oxygen Detected For 1st Time In The Interstellar Medium

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Tuesday, April 17, 2007


Picture courtesy homepage Trinity College Cambridge UK

Superbursts emanate from binary systems in which a neutron star orbits a companion star. When the two stars get close enough together, a steady rain of material is sucked away from the companion star onto the surface of the neutron star.

Because a neutron star is so dense - on Earth, one teaspoonful would weigh a billion tons - the companion star material that reaches the neutron star surface is strongly compressed and heated. Eventually nuclear reactions trigger an explosion that burns through the surface layer of accumulated material, resulting in a burst of X-rays clearly detectable by ground- and space-based instruments.

X-ray bursts repeat every few hours to days, along the way fusing hydrogen and helium into a mixture of elements that is itself potentially reactive. In contrast, superbursts occur when, after many months, the accumulated "ashes" produced in the X-ray bursts ignite in a different, even more dramatic nuclear explosion.

The result is an outpouring of X-rays some 1,000 times as energetic as a standard X-ray burst. One superburst, which lasts only on the order of a few hours, releases as much energy as the sun will radiate in a decade.

Neutron star accreting matter from a red giant star. The red giant (on the upper right) is expanding and dumping material onto the neutron star. This material forms a disk and then finally falls to the neutron star surface. (Credit: Tony Piro, U.C. Berkeley)

A new theoretical thermometer built from heavy-duty mathematics and computer code suggests that the surfaces of certain neutron stars run significantly hotter than previously expected. Hot enough, in fact, to at least partially answer an open question in astrophysics - how to explain the observed frequency of ultra -violent explosions known as superbursts that sometimes ignite on such stars' surfaces?

"This is the first model that goes into some reasonable detail about the nuclear physics that occur in the crusts of accreting neutron stars," said Hendrik Schatz, NSCL professor and co-author of a paper that will be published in The Astrophysical Journal in June. One of Schatz's co-authors, NSCL assistant professor Ed Brown, presented the results April 17 at a meeting of the American Physical Society in Jacksonville, Fla.

According to observational data, superbursts occur roughly annually and scientists still aren't altogether sure why - "It's still an open question as to how nature ignites superbursts" - said Brown.

Astrophysical Journal paper, "Heating in the Accreted Neutron Star Ocean: Implications for Superburst Ignition"
Was Einstein Right?
Gravity Probe B Results from Centauri Dreams
Stephen Hawking building named by HRH @ Cambridge University

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Monday, April 16, 2007

The Future starts Today

Hubble mosaic of the galaxy NGC 7319 from Stephan's Quintet.
Located in the constellation Pegasus, 270 million light-years from Earth, it was discovered by Edouard M. Stephan in 1877. As the name suggests, the quintet actually contains five galaxies and is the first compact group ever discovered.

One step closer to shaping ‘Cosmic Vision 2015-2025’

“The future starts today” said ESA’s Director General Jean-Jacques Dordain, addressing the community on 11 April 2007.
Following the call for proposals issued early March this year, ESA received more than 60 ‘Letters Of Intent’. Through these, European research teams expressed their intention to submit proposals for new scientific missions and provided their preliminary concepts.

The mission concepts range from the exploration of Jupiter and its satellite Europa, to satellites studying radiation from the Big Bang and testing theories concerning the inflation of the Universe. The concepts also include missions studying near-Earth asteroids, satellites looking for liquid water on Saturn’s moon Enceladus and spacecraft to verify gravity as one of the fundamental forces.

On 29 June ESA will receive detailed missions proposals. Starting in October 2007, until mid-2009, ESA’s Space Science Advisory committee and scientific working groups will assess the proposals and pre-select three ‘class-M’ missions and three ‘class-L’ missions.

Class-M missions are medium-size projects, where the costs to ESA do not exceed 300 million euros. Class-L missions are larger projects, with cost envelopes not exceeding 650 million euros.

By the end of 2009, out of these three class-M and three class-L missions (plus LISA), two class-M and two class-L missions will further be short-listed for the definition phase (mission ‘phase A’). This phase will be run by European industries on a competitive basis between the beginning of 2010 and mid-2011.

By the end of 2011, one class-M and one class-L mission each will be adopted for implementation with launch foreseen in 2017 and 2018 respectively.

Image taken using Hubble's Wide Field & Planetary Camera 2 on Dec. 30, 1998 and June 17, 1999. Credits: NASA/ESA, J. English (U. of Manitoba), S. Hunsberger (PSU), Z. Levay ( STSI), S. Gallagher (PSU) and J. Charlton (PSU)
Was Einstein Right?
Public Peek At Gravity Probe B Results from Science Daily
Where has all the antimatter gone? VELO from SciTech

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Sunday, April 15, 2007

Where is The Proton?

Scientists Discover Footprints Of Shared Protons

This week in Science, Yale researchers present "roadmaps" showing that shared protons, a common loose link between two biological molecules, simply vibrate between the molecules as a local oscillator, rather than intimately entangling with the molecular vibrations of the attached molecules.

The paper reports clear "roadmaps" for the widely varying, characteristic vibrational frequencies that occur when an excess proton binds together simple nitrogen and oxygen containing molecules.

Rather than studying the proton-trapped pairs of molecules in crystals or in solution at room temperature, as has been common in the past, Johnson's team made their measurements of proton interactions with 18 simple molecules by isolating them in the gas-phase and cooling them to about 50 Kelvin by taking advantage of recent advances in argon nanomatrix spectroscopy.

"Historically it has been very difficult to isolate the signature of an excess proton in a complex environment like a cell membrane, and say with confidence 'Aha, I have one,'" said Johnson. "The proton is in constant motion in a warm, disordered medium, which causes its natural vibrational frequency to spread out over a huge spectral range. As a result, its 'signature' is often thought to comprise the continuous 'junk' background in the vibrational spectra of protonated samples."

"When we cool the isolated systems, the protons sing out their sharp vibrational frequencies, and therefore provide clear signatures that are characteristic of each kind of interaction," said Johnson.

Two oxygen atoms on different molecules are connected by their mutual attraction to an extra proton, shown as a fuzzy ball between them. The presence of such intermolecular binding can now be identified by monitoring the precise vibrational frequency of the bridging proton. (Credit: Image courtesy of Yale University)

The research shows that the extra proton is associated with a specific pair of atoms on the two tethered molecules, participating in partial chemical bonds to both. "In biological systems, any time you have molecules with a nitrogen or oxygen, and add in an extra proton, the proton forms a bond with one of the extra electron pairs that are available," according Johnson. "It crashes the party and changes the character of the molecule."

Extending Johnson's analogy, if another molecule containing nitrogen or oxygen comes by, the proton crashes that party, too. Because the proton is not deciding between one molecule and the other, it is creating a bond between them - crashing both parties at the same time. "A proton is a great handshaker that works the room until it gets to where it is needed," he said.

This motif is the generic intermediate involved in passing a proton through a biological membrane. Each paired interaction forms a locally stable intermediate. In a sense, the oxygen atoms in water molecules chaperone protons between oxygen and nitrogen atoms on organic structures. For example, the primary events in trans-membrane proton pumps require passing protons through many relay steps across the cell membrane.

In earlier studies, Johnson looked only at water molecules trapping protons. This study expands the work to biologically relevant molecules that contain oxygen and nitrogen atoms. In it the researchers were able to look at how stiff the proton trap is between two molecules, and how this stiffness depends on the properties of the molecules to which the protons are attached.

"The strength with which the proton is grabbed by a nitrogen - or oxygen- containing molecule is highly affected by the environment," said Johnson. "So, we systematically changed that environment over a huge range and followed how the localization of the proton changed. We found that the way the proton is localized depends very much on the chemical properties of the atoms you are trapping it with."

Argon Nanomatrix Spectroscopy by Mark A Johnson
Mew NMR Methods by Kurt W Zilm
LUMO Analogy among three fluorides

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Saturday, April 14, 2007

Black Hole Eclipse

Chandra observations of the galaxy NGC 1365 have captured a remarkable eclipse of the supermassive black hole at its center. A dense cloud of gas passed in front of the black hole, which blocked high-energy X-rays from material close to the black hole. This serendipitous alignment allowed astronomers to measure the size of the disk of material around the black hole, a relatively tiny structure on galactic scales.

Astronomers were able to measure the disk's size by observing how long it took for the black hole to go in and out of the eclipse. This was revealed during a series of observations of NGC 1365 obtained every two days over a period of two weeks in April 2006. During five of the observations, high-energy X-rays from the central X-ray source were visible, but in the second one - corresponding to the eclipse - they were not.

The Chandra image contains a bright X-ray source in the middle, which reveals the position of the supermassive black hole. An optical view of the galaxy from the European Space Observatory's Very Large Telescope shows the context of the Chandra data.

NGC 1365 contains a so-called active galactic nucleus, or AGN. Scientists believe that the black hole at the center of the AGN is fed by a steady stream of material, presumably in the form of a disk.

Material just about to fall into a black hole should be heated to millions of degrees before passing over the event horizon, or point of no return. The process causes the disk of gas around the central black hole in NGC 1365 to produce copious X-rays, but the structure is much too small to resolve directly with a telescope.

NGC 1365 is about 60 million light years
in the Constellation of Fornax (furnace).

Chandra Sees Remarkable Eclipse Of Black Hole from Science Daily 12th April 2007
More Images of NGC 1365 Eclipse from Chandra X-Ray Observatory

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ESA's Darwin

Search For Extrasolar Planets And Extraterrestrial Life Improved With Darwin's Frictionless Optics

ESA's Darwin mission aims to discover extrasolar planets and examine their atmospheres for the presence of certain life-related chemicals such as oxygen and carbon dioxide.

The major technical challenge lies in distinguishing, or resolving, the light from an extrasolar planet from the hugely overwhelming radiation emitted by the planet's nearby star.
[+/-] Click here to expand

The multi-satellite Darwin mission will use optical interferometry in which at least three separate orbiting telescopes jointly operate as an equivalent single telescope with a much larger effective aperture, thus achieving the required resolution. With this method, multiple smaller telescopes having actual apertures of, for example, 3 metres, can combine to provide an effective aperture of several tens to hundreds of metres, depending on the distance between the individual telescopes.

Creating delicate phase delays
Darwin will use nulling interferometry, a specific interferometric technique used to shield the overwhelming star emissions by precisely delaying the radiation coming from some of the telescopes by a small amount. This, in combination with achromatic - or colour independent - phase shifters, will cancel out the bright star radiation while allowing the much fainter extrasolar planet light to be detected.

A component known as an Optical Delay Line (ODL) is at the core of such interferometric observations. An ODL is a sophisticated opto-mechanical device that can introduce well-defined variations, or delays, in the optical path of a light beam and includes a moving mirror positioned with extremely good accuracy.

Precise movement using magnetic levitation
To demonstrate the critical technology required by Darwin, ESA's Technology Research Programme has sponsored the design and testing of an ODL that uses magnetic levitation for precise, frictionless mirror movement.

Sub-nanometre resolution to be incorporated in future flight mechanism
The ODL has also been thoroughly tested in Darwin's demanding cryogenic environment, at 40 Kelvin - or about -233 Celsius.

Darwin's ODLs are uniquely engineered to operate at cryogenic temperatures to avoid self-interference from the satellites' own thermal radiation. This is mandatory as Darwin will conduct observations at mid-infrared wavelengths, where the planet-to-starlight brightness ratio is relaxed compared to that in visible wavelengths, and where life-related marker chemicals such as water, ozone and carbon dioxide can be detected.

The ODLs will be used in Darwin for co-phasing the light collected by the separate telescopes within a central hub spacecraft, which is responsible for the correct recombination of the light beams and hence achieving the high-performance resolution of a single very large telescope.

NASA Predicts Nongreen Plants On Other Planets
Deep Impact Mission: Aiming For Close-ups Of Extrasolar Planets
Searching for Other Planet Worlds from Centauri Dreams

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Thursday, April 12, 2007

Space Tsunami

The image to the left is the typical appearance of the aurora before a magnetic substorm. During a substorm, the single auroral ribbon may split into several ribbons (centre) or even break into clusters that race north and south (right). Credits: Jan Curtis

Cluster provides new insights into the working of a ‘space tsunami’ that plays a role in disrupting the calm and beautiful aurora, or northern lights, creating patterns of auroral dances in the sky.

Generally seen in high-latitude regions such as Scandinavia or Canada, aurorae are colourful curtains of light that appear in the sky. Caused by the interaction of high-energy particles brought by the solar wind with Earth’s magnetic field, they appear in many different shapes.

Early in the evening, the aurora often forms a motionless green arc that stretches across the sky in the east-west direction. Colourful dancing auroral forms are the results of disturbances known as ‘substorms’ taking place in Earth’s magnetosphere.

These perturbations can affect our daily lives, in particular by affecting the reception of GPS signals. Thus, understanding the physical processes involved is important to our routine life and security.
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These substorms typically last one to two hours and are three-dimensional physical phenomena spread over altitudes from 100 to 150 000 kilometres.

Currently, there are two competing theoretical models to describe these substorms or space tsunamis. The first one is called the ‘Current-Disruption’ model, while the second one is the ‘Near Earth Neutral Line Model’. Using data from the four Cluster spacecraft, a group of scientists from both sides of the Atlantic were able to confirm that the behaviour of some substorms is consistent with the Current Disruption model.

In the late stage of substorm development, auroral disturbances move towards the poles, suggesting that the energy source for auroras and substorms moves away from Earth.

Previous satellite observations have found that, during this late stage, the flows of plasma (a gas of charged particles populating Earth’s magnetosphere) in the magnetotail exhibit a reversal in direction. In recent years it was generally thought that a flow reversal region is where magnetic reconnection takes place, that is where the energy of the magnetic field is converted into particle energy (dissipation effect), resulting in high-speed plasma flows that hurl towards Earth, like space tsunamis.

By comparing the directions of the electric current and the electric field in the magnetosphere it is possible to understand whether the cause of the flow reversal is a dissipation effect (where magnetic field energy converted to particle energy) or a dynamo effect (where particle energy is converted to magnetic field energy). For this case study, the Cluster scientists observed that features associated with flow reversal are actually very complex, consisting of both dissipation and dynamo effects in localised sites.

Read more: Cluster sees tsunamis in space from ESA


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Fermilab Neutrino results

Fermilab - MiniBooNE

Long-standing Neutrino Question Resolved from Science Daily
MiniBooNE opens the box press release Results from Fermilab
MiniBooNe Neutrino Result guest post by Heather Ray @ Cosmic Variance

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Tuesday, April 10, 2007

Spiral Galaxy composite

Composite image of spiral galaxy M106 (NGC 4258). Optical data from the Digitized Sky Survey is shown in yellow, radio data from the Very Large Array appears purple, X-ray data from Chandra is coded blue, and infrared data from the Spitzer Space Telescope appears red. The anomalous arms appear as purple and blue emission.

Credits: NASA/CXC/Univ. of Maryland/A.S. Wilson et al. Optical: Pal.Obs. DSS; IR: NASA/JPL-Caltech; VLA & NRAO/AUI/NSF

Mystery spiral arms explained? from ESA
Hubble's view of barred spiral galaxy NGC 1672
How far are galaxies. The Tully-Fisher Relation from Astroprof
Two Trinities and a Very Large Array (VLA) by Daniel @ Cosmic Variance.

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Galaxy Mergers

Composite image of: Chandra X-ray Image of 3C442A and VLA Radio Image of 3C442A

About 390 million light years away in the Constellation of Pegasus The Winged horse - Two galaxies near the middle of 3C442A in the process of merging.

These two galaxies are on their second pass toward a collision, having already experienced a close encounter. The energy generated from this impending merger is heating the combined atmospheres from these two galaxies, causing them to shine brightly in X-rays and expand.

Researchers have determined that the jets that had produced the lobes of radio-emitting gas are no longer active. The jets may have ceased at the time of, and possibly as a result of, the galaxy collision. Since the radio-emitting gas no longer has a power source, it is then at the mercy of the expanding hot gas and has been pushed aside.

More Images of 3C442A from Chandra X-Ray Observatory
Credit: X-ray: NASA/CXC/Univ. of Bristol/Worrall et al.; Radio: NRAO/AUI/NSF
Dust Clouds In Cosmic Cycle from Science Daily
Testing Relativity from Astroprof @ Astroprof's Page
X-ray satellites catch magnetar in gigantic stellar ‘hiccup’ from ESA

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Sunday, April 08, 2007

Above and Below


All of the observable universe is filled with large numbers of photons, the so-called cosmic background radiation, and quite likely a correspondingly large number of neutrinos.

The current temperature of this radiation is about 3 K, or -270 degrees Celsius.

A vacuum is a volume of space (empty space) that is essentially empty of matter, so that gaseous pressure is much less than standard atmospheric pressure.

A perfect vacuum with a gaseous pressure of absolute zero is a philosophical concept that is never observed in practice, not least because quantum theory predicts that no volume of space is perfectly empty in this way.

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Physicists often use the term "vacuum" slightly differently, to discuss ideal test results that would occur in a perfect vacuum, which is simply called "vacuum" or "free space" in this context, and use the term partial vacuum to refer to the imperfect vacua realized in practice.

The quality of a vacuum is measured by how closely it approaches a perfect vacuum. The residual gas pressure is the primary indicator of quality, and it is most commonly measured in units of torr, even in metric contexts. Lower pressures indicate higher quality, although other variables must also be taken into account. Quantum mechanics sets limits on the best possible quality of vacuum. Outer space is a natural high quality vacuum, mostly of much higher quality than what can be created artificially with current technology.

Much of outer space has the density and pressure of an almost perfect vacuum. It has effectively no friction, which allows stars, planets and moons to move freely along ideal gravitational trajectories. But no vacuum is perfect, not even in interstellar space, where there are a few hydrogen atoms per cubic centimeter at 10 fPa (10 to the minus 16 Torr). The deep vacuum of space could make it an attractive environment for certain processes, for instance those that require ultraclean surfaces, but for small scale applications it is much easier to create an equivalent vacuum on Earth than to leave the Earth's gravity well.

Einstein argued that physical objects are not located in space, but rather have a spatial extent. Seen this way, the concept of empty space loses its meaning. Rather, space is an abstraction, based on the relationships between local objects. Nevertheless, the general theory of relativity admits a pervasive gravitational field, with properties that vary from one location to another. Only, one must take care not to ascribe to it material properties like velocity, and so on.

Stars, planets and moons keep their atmosphere by gravitational attraction, so atmospheres have no clearly delineated boundary. The density of atmospheric gas simply decreases with distance from the object. In Low Earth Orbit (about 300 km altitude) the atmospheric density is about 100 nPa, (10 to the minus 9 Torr,) still sufficient to produce significant drag on satellites. Most artificial satellites operate in this region, and they need to fire their engines every few days to maintain orbit.

Beyond planetary atmospheres, the pressure from photons and other particles from the sun becomes significant. Spacecraft can be buffeted by solar winds, but planets are too massive to be affected. The idea of using this wind with a solar sail has been proposed for interplanetary travel.

In 1913, Norwegian explorer and physicist Kristian Birkeland may have been the first to predict that space is not only a plasma, but also contains "dark matter". He wrote: "It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. We have assumed that each stellar system in evolutions throws off electric corpuscles into space. It does not seem unreasonable therefore to think that the greater part of the material masses in the universe is found, not in the solar systems or nebulae, but in "empty" space.

In 1930, Paul Dirac proposed a model of vacuum as an infinite sea of particles possessing negative energy, called the Dirac sea. This theory helped refine the predictions of his earlier formulated Dirac equation and successfully predicted the existence of the positron, which was discovered two years later in 1932. Despite this early success, the idea was soon abandoned in favour of the more elegant quantum field theory.

The development of quantum mechanics has complicated the modern interpretation of vacuum by requiring indeterminacy. Niels Bohr and Werner Heisenberg's uncertainty principle and Copenhagen interpretation, formulated in 1927, predict a fundamental uncertainty in the position of any particle, which, not unlike the gravitational field, questions the emptiness of space between particles. In the late 20th century, this principle was understood to also predict a fundamental uncertainty in the number of particles in a region of space, leading to predictions of virtual particles arising spontaneously out of the void. In other words, there is a lower bound on vacuum which is dictated by the lowest possible energy state of the quantized fields in any region of space. Ironically, Plato was right, if only by chance.

Even an ideal vacuum, thought of as the complete absence of anything, will not in practice remain empty. One reason is that the walls of a vacuum chamber emit light in the form of black-body radiation: visible light if they are at a temperature of thousands of degrees, infrared light if they are cooler. If this soup of photons is in thermodynamic equilibrium with the walls, it can be said to have a particular temperature, as well as a pressure. Another reason that perfect vacuum is impossible is the Heisenberg uncertainty principle which states that no particle can ever have an exact position. Each atom exists as a probability function of space, which has a certain non-zero value everywhere in a given volume. Even the space between molecules is not a perfect vacuum.

More fundamentally, quantum mechanics predicts that vacuum energy can never be exactly zero. The lowest possible energy state is called the zero-point energy and consists of a seething mass of virtual particles that have a brief existence. This is called vacuum fluctuation. While most agree that this represents a significant part of particle physics, it is a concept that would benefit from a deeper understanding than currently available. Vacuum fluctuations may also be related to the so-called cosmological constant in the theory of gravitation, if indeed this entity were to be observed in nature on a macroscopic scale. The best evidence for vacuum fluctuations is the Casimir effect and the Lamb shift.

In quantum field theory and string theory, the term "vacuum" is used to represent the ground state in the Hilbert space, that is, the state with the lowest possible energy. In free (non-interacting) quantum field theories, this state is analogous to the ground state of a quantum harmonic oscillator. If the theory is obtained by quantization of a classical theory, each stationary point of the energy in the configuration space gives rise to a single vacuum. String theory is believed to be analogous to quantum field theory but one with a huge number of vacua - with the so-called anthropic landscape.

Deep space is generally much more empty than any artificial vacuum that we can create, although many laboratories can reach lower vacuum than that of low earth orbit. In interplanetary and interstellar space, isotropic gas pressure is insignificant when compared to solar pressure, solar wind, and dynamic pressure, so the definition of pressure becomes difficult to interpret. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre. The average density of interstellar gas is about 1 atom per cubic centimeter.

Still begs the question what is outside the observable universe.
Laser-cooling Brings Large Object Near Absolute Zero from MIT
LHC cooler than outer space by John @ Cosmic Variance

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Friday, April 06, 2007

Quantum Universe

Science Tunnel - Max Planck Society

Nothing in the physical sciences predicts the phenomenon of consciousness. Yet its reality is apparent to each and every one of us

Consciousness is as fundamental as matter - in some ways, more fundamental. Advances in physics, psychology, and philosophy have shown that reality is not what it seems.

Take vision, for example. When we look at a tree, light reflected from its leafs is focused onto cells in the retina of the eye, where it triggers a cascading chemical reaction releasing a flow of electrons.

Neurons connected to the cells convey these electrical impulses to the brain’s visual cortex, where raw data is processed and integrated. Then — in ways that are still a complete mystery — an image of the tree appears in our consciousness.

It may seem that we are directly perceiving the tree in the physical world, but what we are actually experiencing is an image generated in our mind.

The same is true of every other experience. All that we see, hear, taste, touch, smell and feel has been created from the data received by our sensory organs. All we ever know of the world around are the mental images constructed from that data. However real and external they may seem, they are all phenomena within our mind.

Peter Russell
The Universe as a hologram by Michael Talbot
Play the quantum lottery by John @ cosmicvariance

The human brain stores and processes its information at the level of single organic molecules and is a single macroscopic quantum system. Acts of consciousness may be viewed as incorporating quantum events.


Wednesday, April 04, 2007

Reaching the parts ...

Herschel will be the largest space telescope of its kind when launched. Herschel's 3.5-metre diameter mirror will collect long-wavelength infrared radiation from some of the coolest and most distant objects in the Universe.

Infrared radiation is invisible for the human eye. It is actually 'heat', or thermal radiation. Even objects that we think of as being very cold, such as an ice cube, emit infrared radiation. For this reason, infrared telescopes can observe astronomical objects that remain hidden for optical telescopes, such as cool objects that are unable to emit in visible light.

Earth's atmosphere acts as an 'umbrella' for most infrared wavelengths, preventing them from reaching the ground. A space telescope is needed to detect this kind of radiation invisible to the human eye and to optical telescopes.

The Herschel satellite is a tall 'tube' 7.5 metres high and 4 metres wide, with a launch mass of around 3.3 tonnes. It will carry the infrared telescope and three scientific instruments. The bulk of the spacecraft consists of a liquid helium thermos bottle inside which the instrument detectors sit and are cooled down to only a few degrees above absolute zero.

Herschel will be launched in 2008 with another mission, Planck - a mission to study the cosmic microwave background radiation - on an Ariane rocket. The two spacecraft will separate about 2.5 hours after launch and will operate independently. In less than six months, Herschel will reach its operational orbit around a point in space known as the second Lagrangian point (L2), situated at 1.5 million kilometres away from the Earth.

Exploring formation of stars and galaxies, ESA's Herschel space observatory (formerly called Far Infrared and Submillimetre Telescope, or FIRST) will give astronomers their best view yet of the universe at far-infrared and sub-millimetre wavelengths, bridging the gap in the spectrum between what can be observed from ground and earlier space missions of this kind.

Herschel overview
Reaching the parts .…. with Herschel and SPIRE from SciTech
The Science and Technology Facilities Council SciTech
Formed by Royal Charter in 2007 (by combining CCLRC and PPARC), the Science and Technology Facilities Council is one of Europe's largest multidisciplinary research organisations supporting scientists and engineers world-wide.
The Council operates world-class, large scale research facilities and provides strategic advice to the government on their development.
It also manages international research projects in support of a broad cross-section of the UK research community. The Council also directs, coordinates and funds research, education and training.

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Monday, April 02, 2007

ESA Mars 500 Mission

Preparing for a long-duration human mission to Mars

Starting in spring next year, a crew of six will be sent on a 500 day simulated mission to Mars.

During the simulated Mars mission, known as Mars500, the crew will remain in a special isolation facility in Russia. To investigate the psychological and medical aspects of a long-duration mission, such as to Mars, ESA is looking for experiment proposals for research to be carried out during their stay.

Locked in the facility in Moscow, the crew will be put through all kinds of scenarios as if they really were travelling to the Red Planet – including a launch, an outward journey of up to 250 days, arrival at Mars and, after an excursion to the surface, they will face the long journey home.
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The crew will have tasks similar to those they would have on a real space mission. They will have to cope with simulated emergencies; they may even have real emergencies or illnesses. Communication delays of as much as 20 minutes each way will not make life any easier.

Instead of having a spacecraft as their home, the crew will live in a series of metal tanks. Using narrow connecting passages, they can move between a medical area, a research area, a crew compartment and a kitchen – an area of only 200m2. There is even a special tank representing the Mars descent vehicle for simulation of a stay on the Martian surface.

Why is ESA participating in this study?

To look at the psychology of such a mission, knowing that you are enclosed for 500 days. As soon as there is a problem, the crew knows that they are on their own, and they have to solve it themselves. The only help available from the outside is through communications which may take up to 40 minutes.

At the start of their mission the crew will be supplied with all the food they will have to live off for the duration of the study. They have to keep track of their consumables amongst themselves. This limited food supply could lead to additional tensions amongst the crew.

To look at the psychological effects of the situation on your mental well-being, and on your capabilities of performing certain tasks, even tasks critical to the mission. In a real mission, for example, whether you are able to land a vehicle on the surface of Mars, and are you able to do the science once you are there? How will group relations evolve? What are the potential dangers we could encounter? What kind of countermeasures can we invent that can prevent this? And to learn about what types of personality we should select for a real mission.

Almost as important, to learn more about the medical procedures. How do you define a good medical environment so that you can treat diseases? What are the medicines that you want to take with you on the journey? There will be one person amongst the crew with real medical training. But of course that person can also fall ill. So you have to have all kinds of back-up scenarios.

A full simulation should alert us to any potential risks and better prepare us for the real thing.

The proposal could also cover research in the Concordia Station Credits: IPEV
The Concordia Station is a scientific base built in Antarctica by the French Polar Institute (IPEV) and the Italian Antarctic Programme (PNRA) .

Read more ESA prepares for a human mission to Mars 02 April 2007.

Mars Spots From Astroprofs Page

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