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From: Condor6/9/2008 3:36:01 PM
2 Recommendations   of 1199
 
Distant sunset on Mars.
Thx to Tim Fowler

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From: jrhana6/9/2008 5:13:47 PM
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Hubble Space Telescope Spies Galaxy And Black Hole Evolution In Action

spacedaily.com


Red-light images of post-starburst quasars taken with the Hubble Space Telescope using the Advanced Camera for Surveys (ACS). Each image is ten arcseconds on a side, corresponding to a physical scale of approximately 120,000 light-years given the 3.5 billion light year distances of these objects.

Staff Writers
Baltimore MD (SPX) Jun 09, 2008
A set of twenty-nine Hubble Space Telescope (HST) images of an exotic type of active galaxy known as a "post-starburst quasar" show that interactions and mergers drive both galaxy evolution and the growth of super-massive black holes at their centers.
Mike Brotherton, Associate Professor at the University of Wyoming, is presenting his team's findings at the American Astronomical Society meeting in St. Louis, Missouri.

Other team members include Sabrina Cales, Rajib Ganguly, and Zhaohui Shang of the University of Wyoming, Gabriella Canalizo of the University of California at Riverside, Aleks Diamond-Stanic of the University of Arizona, and Dan Vanden Berk of the Penn State University.

The result is of special interest because the images provide support for a leading theory of the evolution of massive galaxies, but also show that the situation is more complicated than previously thought. Moreover, we may be glimpsing the future of our own Milky Way galaxy.

Over the last decade, astronomers have discovered that essentially every galaxy harbors a supermassive black hole at its center, ranging from ten thousand times the mass of the sun to upwards of a billion times solar, and that there exists a close relationship between the mass of the black hole and properties of its host. When the black holes are fueled and grow, the galaxy becomes active, with the most luminous manifestation being a quasar, which can outshine the galaxy and making it difficult to observe.

In order to explain the relationships between galaxies and their central black holes, theorists have proposed detailed models in which both grow together as the result of galaxy mergers. This hierarchical picture suggests that large galaxies are built up over time through the assembly of smaller galaxies with corresponding bursts of star formation, and that this process also fuels the growth of the black holes which eventually ignite to shine as quasars. Supernova explosions and their dusty debris shroud the infant starburst until the activated quasar blows out the obscuration.

Starbursts fade as they age because the more massive and luminous stars have shorter lifetimes before exploding as supernovas. There should be a phase, however, during which the fading starburst and the quasar can be seen simultaneously.

In the late 1990s, Brotherton discovered a candidate for such a transition object, which possessed the spectral signatures of both a quasar and an older starburst.

The actual burst of star formation, equivalent to a significant fraction of a Milky Way's worth of stars, was already 400 million years old, hence the label "post-starburst"quasar. Hubble images of this single extreme and distant object showed that it was the remnant of a galaxy merger.

In order to find more of these rare post-starburst quasars, Brotherton and his Wyoming-based team turned to the Sloan Digital Sky Survey, the largest catalog of quasar and galaxy spectra in existence. Searching through a candidate list of 15,000 quasars, they identified the signatures of post-starbursts in some 600 objects. Through ground-based telescopes the objects just appear as smudges, without detail.

Brotherton and his team turned the sharp-eyed Hubble Space Telescope and its Advanced Camera for Surveys to observe a subset of these post-starburst quasars that had the strongest and most luminous stellar content. Looking at these systems 3.5 billion light-years away, Hubble, operating without the distortions of an atmosphere, can resolve sub-kiloparsec scales necessary to see nuclear structure and host galaxy morphology.

"The images started coming in and we were blown away," said Brotherton. "We see not only merger remnants as in the prototype of the class, but also post-starburst quasars with interacting companion galaxies, double nuclei, starbursting rings, and all sorts of messy structures."

Hubble snapped pictures of 29 post-starburst quasars in total, using a red-light filter that emphasized the starlight over the glare of the bluer quasar.

"These images provide us tremendous insight into the complexity of galaxy evolution," said team member Dr. Rajib Ganguly. "We see nuclear activity and post-starbursts simultaneously in systems from pre-merger to post-merger and in between."

More work remains to characterize the physics properties of each object, such as the masses and ages of the post-starbursts and the masses and fueling rates of the black holes powering the quasars.

This task will require the combination of the Hubble images with high-quality spectra from the Keck Observatory on Mauna Kea, Hawaii, which team member Gabriella Canalizo has obtained. This more detailed work should provide additional insights into this phase of galaxy evolution.

Astronomers have determined that our own Milky Way galaxy and the great spiral galaxy of Andromeda will collide three billion years from now. This event will create massive bursts of star formation and most likely fuel nuclear activity a few hundred million years later.

Hubble has imaged post-starburst quasars three and a half billion light-years away, corresponding to three and a half billion years ago, and three and a half billion years from now our own galaxy is probably going to be one of these systems.








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From: jrhana6/9/2008 5:18:06 PM
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Scientists Pioneer Method For Making Giant Lunar Telescopes

moondaily.com


After Apollo 12 left lunar orbit this image of the Moon was taken from the command module on 11/24/69. Credit: NASA


by Staff Writers
Greenbelt MD (SPX) Jun 09, 2008
Scientists working at NASA's Goddard Space Flight Center in Greenbelt, Md., have concocted an innovative recipe for giant telescope mirrors on the Moon. To make a mirror that dwarfs anything on Earth, just take a little bit of carbon, throw in some epoxy, and add lots of lunar dust.
"We could make huge telescopes on the moon relatively easily, and avoid the large expense of transporting a large mirror from Earth," says Peter Chen of NASA Goddard and the Catholic University of America, which is located in Washington, D.C. "Since most of the materials are already there in the form of dust, you don't have to bring very much stuff with you, and that saves a ton of money."

Chen and his Goddard colleagues Douglas Rabin, Michael Van Steenberg, and Ron Oliversen are presenting their mirror-making technique in a poster at the 212th meeting of the American Astronomical Society in St. Louis, Mo. They will also describe their results in a press conference on Wednesday, June 4 at 9:30 a.m. CDT.

For years, Chen had been working with carbon-fiber composite materials to produce high-quality telescope mirrors. But Chen and his colleagues decided to try an experiment. They substituted carbon nanotubes (tiny tubular structures made of pure carbon) for the carbon-fiber composites.

When they mixed small amounts of carbon nanotubes and epoxies (glue-like materials) with crushed rock that has the same composition and grain size as lunar dust, they discovered to their surprise that they had created a very strong material with the consistency of concrete. This material can be used instead of glass to make mirrors.

They next applied additional layers of epoxy and spun the material at room temperature. The result was a 12-inch-wide mirror blank with the parabolic shape of a telescope mirror. All of this was achieved with minimal effort and cost.

"After that, all we needed to do was coat the mirror blank with a small amount of aluminum, and voilà, we had a highly reflective telescope mirror," says Rabin.

"Our method could be scaled-up on the moon, using the ubiquitous lunar dust, to create giant telescope mirrors up to 50 meters in diameter." Such an observatory would dwarf the largest optical telescope in the world right now: the 10.4-meter Gran Telescopio Canarias in the Canary Islands.

The capabilities of a 50-meter telescope on the Moon boggle the imagination, according to NASA. With a stable platform, and no atmosphere to absorb or blur starlight, the monster scope could record the spectra of extra solar terrestrial planets and detect atmospheric biomarkers such as ozone and methane.

Two or more such telescopes spanning the surface of the Moon can work together to take direct images of Earth-like planets around nearby stars and look for brightness variations that come from oceans and continents. Among many other projects, it could make detailed observations of galaxies at various distances, to see how the universe evolved.

"Constructing giant telescopes provides a strong rationale for doing astronomy from the moon," says Chen. "We could also use this on-site composite material to build habitats for the astronauts, and mirrors to collect sunlight for solar-power farms."

Chen notes that his group achieved this breakthrough with only the support of small NASA internal seed funds. The carbon nanotubes were contributed by Dan Powell, Lead Nanotechnologist for NASA Goddard. Several amateur astronomers made key contributions by advising and making special epoxy formulations, helping with polishing experiments, and vacuum coating the 12-inch mirror.

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From: jrhana6/9/2008 5:22:16 PM
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NASA Selects MIT-Led Team To Develop Planet-Searching Satellite


spacedaily.com


When the satellite is launched, the cameras will cover the whole sky in two years, getting precise brightness measurements of about two million stars in total. The planets discovered by the satellite would provide prime candidates for followup observations by NASA's new James Webb Space Telescope, which is set for launch in 2013.


by David Chandler
for MIT News
Boston MA (SPX) Jun 09, 2008
A planet-searching satellite planned by scientists from MIT, the Harvard-Smithsonian Center for Astrophysics and NASA-Ames is one of six proposed spacecraft concepts that NASA has picked for further study as part of its Small Explorer (SMEX) satellite program. The planet-searching satellite would have the potential to discover hundreds of "super-Earth" planets, ranging from one to two times Earth's diameter, orbiting other stars.
The six projects, announced last week, were selected from among 32 proposals submitted to NASA in January. Each of the six will receive $750,000 for a detailed six-month feasibility study. In early 2009, two of the projects will get the go-ahead for development at a cost of no more than $105 million, excluding the launch vehicle, with the first launch as early as 2012.

The proposed satellite, called the Transiting Exoplanet Survey Satellite (TESS), would use a set of six wide-angle cameras with large, high-resolution electronic detectors (CCDs) being developed in cooperation with MIT's Lincoln Laboratory, to provide the first-ever spaceborne all-sky survey of transiting planets around the closest and brightest stars.

The satellite would search for stars whose orbits as seen from Earth carry them directly in front of the star, obscuring a tiny amount of starlight. Some ground-based searches have used this method and found about 50 giant planets so far, but a space-based search could detect much smaller Earth-sized planets, as well as those with larger orbits.

This transit-detection method can pinpoint the planet's size by measuring the exact amount of light obscured by the planet. Spectroscopic followup observations can then determine the planet's mass and thus its density, giving clues to its composition, as well as determine its temperature, probe the chemistry of its atmosphere, and perhaps even find signs of life such as oxygen in its air.

Plans for TESS are being led by senior research scientist George R. Ricker, at the MIT Kavli Institute for Astrophysics and Space Research, as Principal Investigator, along with research scientist Roland Vanderspek and Jacqueline Hewitt, MIT professor of physics and director of the MIT Kavli Institute, and professors Sara Seager, Adam Burgasser, Jim Elliot and Josh Winn and others at MIT.

TESS is part of a joint effort between the Department of Physics and the Department of Earth, Atmospheric and Planetary Sciences at MIT to study exoplanets.

The project also involves scientists at the Harvard-Smithsonian Center for Astrophysics, including astronomer David Latham as Chief Mission Scientist, and Kimberley A. Ennico of NASA Ames Research Center as the Project Scientist.

The NASA Ames Research Center is a full partner in the TESS program. Their Small Spacecraft Division, formed in 2006, specializes in low-cost, rapid development of spacecraft and missions. Additional TESS partners include the NASA Goddard Space Flight Center, the Harvard Origins of Life Initiative, Lowell Observatory, Caltech's IPAC, the SETI Institute, Geneva Observatory in Switzerland, Tokyo Institute of Technology, SUPAERO in France, ATK Space, Espace Inc, and the privately-funded Las Cumbres Observatory Global Telescope Network.

The satellite's high-resolution, wide-field digital cameras are already under development, thanks to a seed grant from Google. The project has also received funding from the Kavli Foundation, the Smithsonian Institution, MIT alumnus Rick Tavan, and other donors.

When the satellite is launched, the cameras will cover the whole sky in two years, getting precise brightness measurements of about two million stars in total. The planets discovered by the satellite would provide prime candidates for followup observations by NASA's new James Webb Space Telescope, which is set for launch in 2013.

Statistically, since the orientation of orbits is random, about one star out of a thousand will have a planet whose orbit is oriented so that the planet regularly crosses in front of the star, resulting in a "planetary transit". So, out of the two million stars observed, the new observatory should be able to find more than a thousand planetary systems within two years.

"Because the TESS survey will systematically examine the entire sky for stars harboring exoplanets, the resulting TESS Transit Catalog will constitute a unique scientific legacy. Decades or even centuries after the survey is completed, it is likely that TESS-discovered super-earths will continue to be studied because of their proximity to Earth, and because their stars are so bright," Ricker said.

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From: jrhana6/10/2008 8:10:30 AM
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Detective astronomers unearth hidden celestial gem


esa.int



Supernova remnant G350.1-0.3 and its neutron star


10 June 2008

ESA’s orbiting X-ray observatory XMM-Newton has re-discovered an ignored celestial gem. The object in question is one of the youngest and brightest supernova remnants in the Milky Way, the corpse of a star that exploded around 1000 years ago.

Its shape, age and chemical composition will allow astronomers to better understand the violent ways in which stars end their lives.

Exploding stars seed the Universe with heavy chemical elements necessary to build planets and create life. The expanding cloud of debris that each explosion leaves behind, known as a supernova remnant (SNR), is a bright source of X-rays and radio waves. Generally, the debris is thought to appear as an expanding bubble or ring.

When astronomers took the first high-resolution radio images of a celestial object known as ‘G350.1-0.3’ in the 1980s, they saw an irregular knot of gases that did not seem to meet these expectations. So it was classified as a probable background galaxy and was quietly forgotten.


Now Bryan Gaensler and Anant Tanna, both at the University of Sydney, have used the X-ray capabilities of XMM-Newton with their colleagues to prove that appearances can be deceptive. G350.1-0.3 is indeed the debris of an exploded star despite its misshapen configuration.

In fact, it turns out to be one of the youngest and brightest supernova remnants in the Milky Way.

To explain its shape, the team looked at radio surveys and discovered that G350.1-0.3 had exploded next to a dense cloud of gas about 15 000 light-years from Earth. The cloud prevented the blast from expanding evenly in all directions, resulting in an example of a rare kind of misshapen supernova remnant.

G350.1-0.3 is incredibly small and young in astronomical terms, only eight light years across and about 1000 years old. “Only a handful of such young supernova remnants are known. So even having one more is important,” says Tanna. That is because young supernova remnants are highly luminous, with the newly-formed chemical elements glowing brightly, making them easier to study.



An artist's impression of XMM-Newton

“We're seeing these heavy elements fresh out of the oven,” says Gaensler. Young supernova remnants exhibit the newly created elements and also contain clues about the way the original star exploded. Such information is lost in most supernova remnants because, as they expand and age, they lose their initial characteristics. “After 20 000 years, all sorts of explosions look more or less the same,” says Gaensler.

Astronomers now recognise that stars explode in many different ways. Some might be just big enough for an explosion to occur, others might be much more massive. There are differences in the chemical composition of the exploding stars and some may have a companion star in orbit around them.

Gaensler and Tanna hope that further investigations of G350.1-0.3 will yield clues as to exactly what kind of star exploded. “It may turn out that many of the youngest supernova remnants have these strange shapes,” says Tanna, “The hunt to find more is now on.”


Despite the light from the supernova having reached Earth during the time of William the Conqueror, Gaensler thinks humans would not have seen it. “The X-ray data tell us that there's a lot of dust lying between it and Earth. Even if you'd been looking straight at it when it exploded, it would've been invisible to the naked eye,” he says.

Thankfully, XMM-Newton’s sensitivity and the detective work by Gaensler and Tanna mean that this important celestial object will never again be forgotten.


Notes for editors:

These findings will be published today in ‘The (re-)discovery of G350.1–0.3: A young, luminous supernova remnant and its neutron star’ by B. Gaensler, A. Tanna, P. Slane, C. Brogan, J. Gelfand, N. McClure-Griffiths, F. Camilo, C. Ng and J. Miller in The Astrophysical Journal Letters.


For more information:

Bryan Gaensler, School of Physics, University of Sydney
Email: Bgaensler @ usyd.edu.au

Norbert Schartel, ESA XMM-Newton Project Scientist
Email: Norbert.Schartel @ esa.int

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From: jrhana6/10/2008 8:26:37 AM
   of 1199
 
Making Sense of Mars Methane








By David Tenenbaum

astrobio.net


Commercial salt ponds near the Mexican town of Guerrero Negro, which lies about midway down the Baja California peninsula, produce methane gas that may help scientists understand the origin of methane in Mars’s atmosphere. Click image to enlarge.

In a quest to understand the source of methane detected in the atmosphere of Mars, NASA scientists are looking at methane bubbling from the ground at an outdoor salt factory on Mexico’s Baja Peninsula. By measuring carbon isotopes in the Mexican methane, these scientists hope to help unravel the mystery of the martian methane. In particular, they want to know whether or not the martian methane, like most methane on Earth, is made by microbes.

The 2003-2004 observations of methane on Mars (ranging from 7 to 200 parts per billion) were made remotely by three teams working with separate data, and their accuracy is still under debate, says Brad Bebout, a microbiologist at NASA’s Ames Research Center. But if the methane is truly present in the atmosphere of Mars, then something must be producing it on the planet now, because the gas is broken down by sunlight within 300 years.Most methane in Earth’s atmosphere is made by primitive microbes called archaea that reside in anaerobic locations like rice paddies and the guts of ruminants like cows. However, methane is also produced non-biogenically, by reactions between water and hot, carbon-bearing rocks, or by the natural decay of coal and petroleum.Methane, composed of one carbon and four hydrogen atoms, attracts a lot of attention from astrobiologists “because it is a key biomarker,” says Bebout. “But methane can be produced by non-biological means, so when you see it in the atmosphere of a planet, biology was not necessarily involved, and that’s why we want to know about isotopes.”Isotopes are key to understanding the origin of methane because organisms tend to use more of the lighter isotopes. Biogenic methane usually – but not always – contains a higher percentage of the lighter carbon-12 than non-biogenic methane, which contains relatively more of the heavier carbon-13. The two types of carbon atoms both have the same number of protons, but carbon-13 has one more neutron than carbon-12.


In the ponds where salt is most highly concentrated, sodium chloride (table salt), gypsum and other minerals precipitate out of a briny solution.

Isotopic measurements of the carbon in martian methane are a goal of the tunable laser spectrometer on NASA’s Mars Science Laboratory, a rover now scheduled for launch in Fall 2009. But to get context for interpreting that data, scientists want more information on how primitive life produces methane on Earth, and one of the best locations for that is the salt factory on Baja.The salt flats of Guerrero Negro (the name, “black warrior,” is taken from a nearby shipwreck) are an excellent outdoor laboratory because pools of increasing salinity are created as ocean water is evaporated to concentrate the salt. In many of the pools, microbial mats dominated by salt-tolerant cyanobacteria generate small amounts of methane, which is made by archaea living in association with the photosynthetic cyanobacteria. Bebout has identified these archaea, and is working on measuring their individual contributions to the overall level of methane.This microbial mat is absent in the hyper-saline Area 9, where methane is even more abundant: a stream of gas containing about 50 percent methane is bubbling up to the salty surface. “In that area, there is no mat; the bottom is basically solid gypsum,” says Bebout.Apparently that gypsum is home to some archaea, because the carbon isotopes suggest that the methane bubbles have a biological origin. The isotopes, however, are not conclusive, because they are slightly outside the accepted range for biogenic methane. In cases like these, scientists can try to clarify the methane’s origin by looking not only at its carbon atoms, but also at its hydrogen atoms. Hydrogen has two stable (non-radioactive) isotopes: protium (containing one proton and no neutrons) and deuterium (one proton plus one neutron).


The green and red layers seen here are microbial communities living within the gypsum crust found in Guerrero Negro’s Area 9.Credit: NASA

The combined isotopes of the hydrogen and carbon in the Area 9 methane are in a range “that is usually not considered biological,” says Bebout. However, when the geologic conditions are taken into account, “It's very unlikely this is caused by water-rock interactions, or is thermogenic – resulting from the decay of organic matter – so we are pretty sure it is biological."Carbon and hydrogen isotopes in the Area 9 methane comprise “a pretty unique signature,” which falls outside the accepted range of biogenic methane, and thus begs for a more complete explanation, says isotope expert Jeff Chanton, a professor of oceanography at Florida State University. For that reason alone, the salt ponds in Baja are worth studying.The primitive bacteria that are making methane in Area 9 may resemble whatever is making methane on Mars, says Chanton. “If there was life on Mars, it would not be like little green men. It would be some sort of microbe, a prokaryote [a cell without a nucleus]. On Earth, bacteria were the first form of life.”Finding evidence of ancient bacteria on Mars would not be too surprising, considering that early Mars was warm and wet, rather like Earth during the evolution of methane-making bacteria.A better understanding of methanogens in the salt flat and further isotopic study of their methane will help interpret future measurements of the isotopic composition of methane on Mars. The recent detection of highly saline environments on Mars by Mikki Osterloo, of the University of Hawaii, using data from the THEMIS instrument on NASA’s Mars Odyssey orbiter makes the saline investigation all the more important, Bebout says. “We want to really go through the system and characterize all of these environments, which might be like something the MSL rover would stumble on, and figure out what’s going on. On Earth, we can do experiments we can't do on the rover.”Bebout’s research is supported by a grant from NASA’s Exobiology and Evolutionary Biology program.
--------------------------------------------------------------------------------

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From: jrhana6/10/2008 8:34:48 AM
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Searching the Sky for Aliens
Based on a Johns Hopkins University news release




astrobio.net


Allen Telescope Array (ATA)

A Johns Hopkins astronomer is a member of a team briefing fellow scientists about plans to use new technology to take advantage of recent, promising ideas on where to search for possible extraterrestrial intelligence in our galaxy.

Richard Conn Henry, a professor in the Henry A. Rowland Department of Physics and Astronomy at Johns Hopkins' Zanvyl Krieger School of Arts and Sciences, is joining forces with Seth Shostak of the SETI Institute and Steven Kilston of the Henry Foundation Inc., a Silver Spring, Md., think tank, to search a swath of the sky known as the ecliptic plane. They propose to use new Allen Telescope Array, operated as a partnership between the SETI Institute in Mountain View, Calif., and the Radio Astronomy Laboratory at the University of California, Berkeley.

Comprising hundreds of specially produced small dishes that marry modern, miniaturized electronics and innovative technologies with computer processing, the ATA provides researchers with the capability to search for possible
signals from technologically advanced civilizations elsewhere in our galaxy – if, in fact, such civilizations exist and are transmitting in this direction.

Employing this new equipment in a unique, targeted search for possible civilizations enhances the chances of finding one, in the same way that a search for a needle in a haystack is made easier if one knows at least approximately where the needle was dropped, said Henry, who spoke about the proposal at the American Astronomical Society annual meeting in St. Louis.


The disk of our Milky Way Galaxy. Most of the stars in the Milky Way are concentrated along a region of the sky known as the galactic plane. The initial search will concentrate at the point where the galactic plane and the ecliptic plane meet.
Credit: Serge Brunier


According to the researchers, the critical place to look is in the ecliptic, a great circle around the sky that represents the plane of Earth's orbit. The sun, as viewed from Earth, appears annually to pass along this circle. Any civilization that lies within a fraction of a degree of the ecliptic could annually detect Earth passing in front of the sun. This ecliptic band comprises only about 3 percent of the sky.

"If those civilizations are out there – and we don't know that they are – those that inhabit star systems that lie close to the plane of the Earth's orbit around the sun will be the most motivated to send communications signals toward Earth," Henry said, "because those civilizations will surely have detected our annual transit across the face of the sun, telling them that Earth lies in a habitable zone, where liquid water is stable. Through spectroscopic analysis of our atmosphere, they will know that Earth likely bears life.

"Knowing where to look tremendously reduces the amount of radio telescope time we will need to conduct the search," he said.

Most of the 100 billion stars in our Milky Way galaxy are located in the galactic plane, forming another great circle around the sky. The two great circles intersect near Taurus and Sagittarius, two constellations opposite each other in the Earth's sky – areas where the search will initially concentrate.

"The crucial implication is that this targeted search in a favored part of the sky -- the ecliptic stripe, if you will – may provide us with significantly better prospects for detecting extraterrestrials than has any previous search effort," Kilston said.


Earth as seen by the departing Voyager spacecraft: our planet as a tiny, pale blue dot. Could distant civilizations be sending messages in our direction?
Credit: NASA


Ray Villard of the Space Telescope Science Institute, who will join the team in its observations, said that in November 2001, STScI publicized Hubble Space Telescope observations of a transiting planet and "it occurred to me that alien civilizations along the ecliptic would likely be doing similar observations to Earth."

"Once they had determined Earth to be habitable, they might initiate sending signals," Villard said.

Shostak of SETI notes that the Allen Telescope Array is ideal for the team's plans to search the entire ecliptic over time, and not just the intersections of the ecliptic and galactic planes.

The team's presentation at the AAS meeting also explores possible scenarios for the appearance of civilizations in our galaxy.

These models are nothing but pure speculation. But hey … it is educational to explore possibilities," Henry said. "We have no idea how many – if any – other civilizations there are in our galaxy. One critical factor is how long a civilization – for example, our own – remains in existence. If, as we dearly hope, the answer is many millions of years, then even if civilizations are fairly rare, those in our ecliptic plane will have learned of our existence. They will know that life exists on Earth and they will have the patience to beam easily detectable radio (or optical) signals in our direction, if necessary, for millions of years in the hope, now realized, that a technological civilization will appear on Earth."

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From: jrhana6/10/2008 9:00:25 AM
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Sun Goes Longer Than Normal Without Producing Sunspots

spacedaily.com


Periods of inactivity are normal for the sun, but this period has gone on longer than usual. (Photo courtesy of NASA).

by Staff Writers
Bozeman MT (SPX) Jun 10, 2008
The sun has been laying low for the past couple of years, producing no sunspots and giving a break to satellites.
That's good news for people who scramble when space weather interferes with their technology, but it became a point of discussion for the scientists who attended an international solar conference at Montana State University.

Approximately 100 scientists from Europe, Asia, Latin America, Africa and North America gathered June 1-6 to talk about "Solar Variability, Earth's Climate and the Space Environment."

The scientists said periods of inactivity are normal for the sun, but this period has gone on longer than usual.

"It continues to be dead," said Saku Tsuneta with the National Astronomical Observatory of Japan, program manager for the Hinode solar mission. "That's a small concern, a very small concern."

The Hinode satellite is a Japanese mission with the United States and United Kingdom as partners. The satellite carries three telescopes that together show how changes on the sun's surface spread through the solar atmosphere.

MSU researchers are among those operating the X-ray telescope. The satellite orbits 431 miles above ground, crossing both poles and making one lap every 95 minutes, giving Hinode an uninterrupted view of the sun for several months out of the year.

Dana Longcope, a solar physicist at MSU, said the sun usually operates on an 11-year cycle with maximum activity occurring in the middle of the cycle. Minimum activity generally occurs as the cycles change. Solar activity refers to phenomena like sunspots, solar flares and solar eruptions. Together, they create the weather than can disrupt satellites in space and technology on earth.

The last cycle reached its peak in 2001 and is believed to be just ending now, Longcope said. The next cycle is just beginning and is expected to reach its peak sometime around 2012. Today's sun, however, is as inactive as it was two years ago, and scientists aren't sure why.

"It's a dead face," Tsuneta said of the sun's appearance.

Tsuneta said solar physicists aren't like weather forecasters; They can't predict the future. They do have the ability to observe, however, and they have observed a longer-than-normal period of solar inactivity. In the past, they observed that the sun once went 50 years without producing sunspots. That period coincided with a little ice age on Earth that lasted from 1650 to 1700.

Tsuneta said he doesn't know how long the sun will continue to be inactive, but scientists associated with the Hinode mission are ready for it to resume maximum activity.

They have added extra ground stations to pick up signals from Hinode in case solar activity interferes with instruments at other stations around the world. The new stations, ready to start operating this summer, are located in India, Norway, Alaska and the South Pole.

Establishing those stations, as well as the Hinode mission, required international cooperation, Tsuneta said. No one country had the resources to carry out those projects by itself.

Four countries, three space agencies and 11 organizations worked together on Hinode which was launched in September 2006, Tsuneta said. Among the collaborators was Loren Acton, a research professor of physics at MSU. Tsuneta and Acton worked together closely from 1986-2002 and were reunited at the MSU conference.

"His leadership was immense, superb," Tsuneta said about Acton.

Acton, 72, said he is still enthused by solar physics and the new questions being raised. In fact, he wished he could knock 22 years off his age and extend his career even longer.

"It's too much fun," he said. "There's so much exciting stuff come up, I would like to be part of it."

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From: jrhana6/10/2008 11:59:41 AM
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Hubble's Sweeping View of the Coma Cluster of Galaxies


hubblesite.org





ABOUT THIS IMAGE:
NASA's Hubble Space Telescope captures the magnificent starry population of the Coma Cluster of galaxies, one of the densest known galaxy collections in the universe.

The Hubble's Advanced Camera for Surveys viewed a large portion of the cluster, spanning several million light-years across. The entire cluster contains thousands of galaxies in a spherical shape more than 20 million light-years in diameter.

Also known as Abell 1656, the Coma Cluster is over 300 million light-years away. The cluster, named after its parent constellation Coma Berenices, is near the Milky Way's north pole. This places the Coma Cluster in an area unobscured by dust and gas from the plane of the Milky Way, and easily visible by Earth viewers.

Most of the galaxies that inhabit the central portion of the Coma Cluster are ellipticals. These featureless "fuzz-balls" are pale goldish brown in color and contain populations of old stars. Both dwarf, as well as giant ellipticals, are found in abundance in the Coma Cluster.

Farther out from the center of the cluster are several spiral galaxies. These galaxies have clouds of cold gas that are giving birth to new stars. Spiral arms and dust lanes "accessorize" these bright bluish-white galaxies that show a distinctive disk structure.

In between the ellipticals and spirals is a morphological class of objects known as S0 (S-zero) galaxies. They are made up of older stars and show little evidence of recent star formation; however, they do show some assemblage of structure — perhaps a bar or a ring, which may give rise to a more disk-like feature.

This Hubble image consists of a section of the cluster that is roughly one-third of the way out from the center of the cluster. One bright spiral galaxy is visible in the upper left of the image. It is distinctly brighter and bluer than galaxies surrounding it. A series of dusty spiral arms appears reddish brown against the whiter disk of the galaxy, and suggests that this galaxy has been disturbed at some point in the past. The other galaxies in the image are either ellipticals, S0 galaxies, or background galaxies far beyond the Coma Cluster sphere.

The data of the Coma Cluster were taken as part of a survey of a nearby rich galaxy cluster. Collectively they will provide a key database for studies of galaxy formation and evolution. This survey will also help to compare galaxies in different environments, both crowded and isolated, as well as to compare relatively nearby galaxies to more distant ones (at higher redshifts).

For additional information, contact:

Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
villard@stsci.edu

Lars Lindberg Christensen
Hubble/ESA, Garching Germany
011-49-89-3200-6306
lars@eso.org

Object Names: Coma Cluster, Abell 1656

Image Type: Astronomical


Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Acknowledgment: D. Carter (Liverpool John Moores University) and the Coma HST ACS Treasury Team

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To: jrhana who wrote (863)6/10/2008 12:08:02 PM
From: jrhana
   of 1199
 
There are several more spectacular images at the bottom of this link

hubblesite.org


Also (and this is only for those with too much time on their hands) if you down load these images where indicated, it just keeps getting better:


hubblesite.org

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