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Space.gs

Hubble Space Telescope: evidence that galaxies are embedded in halos of dark matter.
03/12/09





The NASA/ESA Hubble Space Telescope has uncovered a strong new line of evidence that galaxies are embedded in halos of dark matter. Peering into the tumultuous heart of the nearby Perseus galaxy cluster, Hubble discovered a large population of small galaxies that have remained intact while larger galaxies around them are being ripped apart by the gravitational tug of other galaxies.

Dark matter is an invisible form of matter that accounts for most of the Universe’s mass. Astronomers have deduced the existence of dark matter by observing its gravitational influence on normal matter, consisting of stars, gas, and dust. The Hubble images provide further evidence that the undisturbed galaxies are enshrouded by a “cushion” of dark matter, which protects them from their rough-and-tumble neighborhood.

“We were surprised to find so many dwarf galaxies in the core of this cluster that were so smooth and round and had no evidence at all of any kind of disturbance,” says astronomer Christopher Conselice of the University of Nottingham, U.K., and leader of the Hubble observations. “These dwarfs are very old galaxies that have been in the cluster a long time. So if something was going to disrupt them, it would have happened by now. They must be very, very dark-matter-dominated galaxies.” Continued...

Space.gs

ESA postpones launch of Herschel Space Telescope and Planck spacecraft.
03/13/09





In order to carry out additional checks on the ground segment of the Herschel and Planck programmes, Arianespace and ESA have jointly agreed to postpone the launch initially planned for 16 April 2009. A new launch date will be announced at the end of March. The decision to postpone the launch by a few weeks was needed to finalise the validation of the spacecraft operations procedures following recent software updates. In the meantime, the preparation of the two spacecraft for launch continues as planned at Europe's Spaceport in Kourou, French Guiana.

The three scientific instruments on the Herschel payload have passed their functional tests and have been declared 'good to go'. This marks another milestone in the steady progress being made in preparing the spacecraft for launch. In the course of the past two weeks all three of Herschel's instruments, SPIRE, PACS and HIFI, have undergone short functional tests. Each instrument team carried out a number of pre-defined tests in normal (as opposed to superfluid) helium conditions in order to verify the health of the instruments after transport to Kourou. All instruments performed flawlessly and passed their pre-launch reviews. The next time that they will be heard from will be a few days after launch when they will be switched on one-by-one as part of the payload check-out process. Continued...




- The Planck spacecraft was meticulously cleaned with a special vacuum hoover. The spacecraft's surface was inspected using UV light to detect dust particles that fluoresce after illumination with UV. Image credit: European Space Agency

03/24/09: European receiver shipped to Atacama Large Millimetre/sub-millimetre Array.

- The Atacama Large Millimeter/submillimeter Array (ALMA), one of the largest ground-based astronomy projects of the next decade, is a major new facility for world astronomy. ALMA will be comprised of a giant array of 12-m submillimetre quality antennas, with baselines of several kilometres. An additional, compact array of 7-m and 12-m antennas is also foreseen. Construction of ALMA started in 2003 and will be completed in 2012. The ALMA project is an international collaboration between Europe, Japan and North America in cooperation with the Republic of Chile. Credit: (caption and image) European Southern Observatory


Equipment that is vital to the international ALMA project destined to revolutionise knowledge of the Universe is due to be shipped to Chile from the Science and Technology Facilities Council's (STFC's) Rutherford Appleton Laboratory (RAL) in Oxfordshire this week. (25th March 2009). The first of the vital receiver systems which have been assembled and tested at the European Front-End Integration Centre (FEIC) located at RAL, will become part of the Atacama Large Millimetre/sub-millimetre Array (ALMA) project in the Atacama Desert in Chile.

ALMA is a huge set-up of sixty six individual antennas, of 12- and 7- metre diameter, that when electronically combined simulate a telescope diameter of up to 15km - more than a thousand times the size of a single antenna! The telescope operates in the millimetre and sub-millimetre wavelength window, which is invisible to the human eye and lies between the infrared and radio regions of the electromagnetic spectrum. Its vast size will allow astronomers to detect signals within and outside of our galaxy with greater clarity than has previously been possible. ALMA will be used to detect and study the earliest and most distant galaxies and will also probe deep into dust-obscured regions where visible-light observations cannot be made and allow us to investigate the birthplace of stars and planets. Continued...

BBC News

Satellite prepares to go super-cold
By Paul Rincon, BBC News


Prof. George Smoot


George Smoot wants to know the answers to some big questions. "I want to know how the Universe came into being, how it developed and what its future might be," he says. The US Nobel Laureate has spent a large part of his career investigating the Cosmic Microwave Background (CMB) - the "first light" released after the Big Bang. Scientists like Professor Smoot study this remnant radiation from the birth of the Universe in the hope of answering some of these questions.

That dim afterglow, which fills the entire sky today, carries a wealth of information about the cosmos in its infancy. "When we look back to the past, we can see everything between the past and now, and that allows us to project to the future," Professor Smoot says. The researcher, from the Lawrence Berkeley National Laboratory (LBNL) in California, shared last year's Nobel Prize in Physics with collaborator John Mather for work on the Cosmic Background Explorer (Cobe) mission. The Cobe satellite detected subtle temperature variations in the CMB which pointed to the ripples in density that gave rise to the first stars and galaxies.

• Superior precision

COBE Cosmic Background Explorer (more)


Another US spacecraft, the Wilkinson Microwave Anisotropy Probe (WMap), was launched in 2001. It has helped constrain estimates for the age of the Universe, shed important light on its composition and has shown that its shape is very close to flat. In the middle of 2009, the third satellite to investigate the CMB will blast off on a mission to address similar issues - but from a fresh perspective. The European Space Agency's (Esa) Planck satellite, named after the great German physicist Max Planck, will map the background sea of microwaves with unparalleled precision.

Professor Smoot was talking at a news conference to mark the approaching end of Planck's physical "integration" as a satellite at the aerospace firm Alcatel Alenia Space's facility in Cannes, France. "We are proposing that this mission creates a recipe that will allow us to better understand the Universe," said Jan Tauber, Planck's project scientist. Professor Smoot added: "With Planck, we are exploiting the relic radiation from the Big Bang. That's difficult to do unless you have contrast."

• Accepted theory

Planck will sit some 1.5 million km from Earth


Contrast is a key strength of Planck. It will look at nine wavelength bands in the electromagnetic spectrum - the range of all possible radiation from gamma rays through to visible light and radio waves. The CMB has a well defined "signature" in this spectrum. "We can use the nine bands to distinguish the CMB from the other foreground signals in the sky," said the LBNL scientist. Planck's superior sensitivity, angular resolution and frequency range should open up some hazy areas in our understanding of the cosmos.

Few scientists today would question the broad details of the Big Bang model, in which the Universe was born in a hot, dense fireball that gradually expanded and cooled. But some fundamental details about the nature and evolution of the Universe are missing. For example, only 4% of the Universe is made up of ordinary matter that we can see. The rest is dark energy (73%) and dark matter (23%). Their influence can be detected indirectly, but scientists do not understand their nature. Planck could provide new information on dark energy, but it will depend on what this mysterious quantity is. This hypothetical form of energy has negative pressure and permeates all of space. Scientists have proposed two main ideas for what dark energy might be.


A Brief History of Background Radiation Discovery / 2 / 3 / 4 / 5

- Some 380,000 years after the Big Bang, matter and radiation are said to have "decoupled". Matter went on to form stars and galaxies; the radiation spread out and cooled. The radiation - the CMB - now shines at radio wavelengths, at a frigid -270.45C. Cobe showed the CMB's profile to follow a predicted distribution - a so-called blackbody curve. Cobe mapped tiny temperature fluctuations (mottled colours, top) in the CMB. These fluctuations (anisotropy) correspond to the early distribution of matter. The data informs scientists about the age, geometry and fate of the cosmos. Images from the more advanced WMap probe show finer detail. The Planck telescope is expected to obtain the best resolution images yet.

• Dynamic field

Planck will make a full sky survey of the CMB (more)

One is the so-called cosmological constant, originally put forward by Albert Einstein. This represents a constant energy density which fills space homogeneously. The second idea is that dark energy is a dynamic field, called quintessence, whose energy density varies in time and space. "If [dark energy] is the cosmological constant, then Planck doesn't provide that much extra information," Professor Smoot explained. "But if it's some kind of complicated dark energy, like quintessence, then it's quite possible that Planck will provide some key details."

Researchers want to confirm whether the very early cosmos underwent a short phase of exponential expansion, called inflation. "Inflation makes our model of the Universe fit in one piece, but it is still quite a mysterious thing," said Jan Tauber. "We want to understand whether it actually happened and, if so, what made it happen." In addition, scientists want to understand why we live at a time when the expansion of the Universe is accelerating again. "We have this model in which the Universe flares out. Then it slows down again, allowing structures to form," said George Smoot. "Now, we have this flaring in which the age of structure formation is coming to an end and the expansion of the Universe is speeding up again."

• Magic numbers

Rst.gsfc.nasa.gov


Cosmologists have built their models of the Universe on a dozen or so "magic numbers" that explain its large-scale properties. Planck will be able to measure these "cosmological parameters" to a very high degree of accuracy in order to select the model which best fits the Universe around us. Planck consists of a telescope and science instruments placed on top of an octagonal service module. The baffle which surrounds them prevents light from the Sun and Moon interfering with detection of the microwave radiation.

In order to achieve its scientific objectives, Planck's detectors have to operate at very low and stable temperatures. The spacecraft is therefore equipped with a system to cool these detectors to temperatures close to absolute zero (-273.15C), the theoretical state of zero heat energy. "It is an extremely elaborate cryogenic system," said Thomas Passvogel, Planck programme manager at Esa. "I think it's the first time a space mission has gone down to those low temperatures to provide detectors of that sensitivity in continuous operation."

The spacecraft is due to lift off on an Ariane 5 rocket from the Kourou spaceport in French Guiana. The Ariane rocket will carry Planck and another mission, the Herschel infrared telescope, into space simultaneously. With a 3.5m mirror, Herschel will be the orbiting telescope with the largest mirror ever deployed in space. Together, Planck and Herschel will survey the cold Universe. But instead of looking for the formation of the Universe, Herschel's primary mission will be to see the formation of stars and galaxies.


Leaderu.com: Stephen Hawking, the Big Bang, and God

US President Barack Obama is joined by members of Congress and school children as he talks March 24, 2009, with astronauts on the International Space Station from the Roosevelt Room at the White House. Others seated include Sen. Kay Bailey Hutchison (R-Texas), left; John Holdren, second left, Director of the Office of Science and Technology Policy; and Sen. Bill Nelson (D.-Fla), right, who flew aboard the space shuttle in 1986. Credit: White House Photo/Pete Souza.


• Video

- President Barack Obama is joined by members of Congress, including former astronaut Sen. Bill Nelson (D.-Fla), right, and school children as he talks with astronauts on the International Space Station from the Roosevelt Room at the White House. (more)

STS-119: Discovery to undock from ISS on Wednesday



- March 23: Astronaut Richard Arnold, STS-119 mission specialist, participates in the mission's third scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 27-minute spacewalk, Arnold and Joseph Acaba (out of frame), mission specialist, helped robotic arm operators relocate the Crew Equipment Translation Aid (CETA) cart from the Port 1 to Starboard 1 truss segment, installed a new coupler on the CETA cart, lubricated snares on the "B" end of the space station's robotic arm and performed a few "get ahead" tasks. Credit: NASA (more)

• Questions and Answers: Askthephysicist.com • www.space.com/common/forums • www.physforum.com • Online Book: Human Knowledge: Foundations and Limits


• www.satnews.com • ESA: Spacecraft Operations

- March 19: Astronaut Richard Arnold, STS-119 mission specialist, participates in the mission's first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, seven-minute spacewalk, Arnold and astronaut Steve Swanson (out of frame), mission specialist, connected bolts to permanently attach the S6 truss segment to S5. The spacewalkers plugged in power and data connectors to the truss, prepared a radiator to cool it, opened boxes containing the new solar arrays and deployed the Beta Gimbal Assemblies containing masts that support the solar arrays. Credit: NASA


Space Shuttle Discovery to undock from the Space Station today
By Space News, March 25, 2009, MCC. Houston, Texas


• Space Shuttle Information • NASA Television • Photos / 2 (more)


After more than four months in space, astronaut Sandra Magnus takes the first step on the road home today when space shuttle Discovery undocks from the International Space Station. The shuttle crew was awakened at 5:14 a.m. CDT today with the song 'Dirty Water' by the Standells, played for Pilot Tony Antonelli, who'll be at the controls of Discovery when it undocks from the station.

The shuttle and station crew members will take care of the final transfers of equipment and supplies this morning, including leaving a 12th container of water on the station, moving two spacesuits back to Discovery and transferring two double cold bags containing temperature-sensitive experiment samples to the shuttle for return to Earth. The 10 crew members will gather in the Harmony module at 11:53 a.m. for a farewell ceremony before shuttle Commander Lee Archambault leads his crew back into Discovery. He and station Commander Mike Fincke will close the hatches between their two vehicles.

At 2:53 p.m. Antonelli will command Discovery to release the station's Pressurized Mating Adapter 2 as springs push the shuttle out in front of the station. At a distance of 400 feet, Antonelli will start circling the station so the shuttle's crew and cameras can get the first look at the completed truss structure and the fourth set of solar array wings fully deployed. Then the thrusters will be fired to move Discovery away from the station to start the journey home for a planned landing on Saturday at the Kennedy Space Center. (more)




- March 24, 2009: STS-119 and Expedition 18 crewmembers pose for a group photo following a joint news conference in the Harmony node of the International Space Station while Space Shuttle Discovery remains docked with the station. From the left (bottom row) are NASA astronauts Tony Antonelli, STS-119 pilot; Lee Archambault, STS-119 commander; and Joseph Acaba, STS-119 mission specialist. From the left (middle row) are NASA astronauts Sandra Magnus, STS-119 mission specialist; and Michael Fincke, Expedition 18 commander; along with cosmonaut Yury Lonchakov and Japan Aerospace Exploration Agency astronaut (JAXA) Koichi Wakata, both Expedition 18 flight engineers. From the left (top row) are NASA astronauts Steve Swanson, Richard Arnold and John Phillips, all STS-119 mission specialists. Magnus, who joined the station's Expedition 18 crew in November 2008, is being replaced by Wakata, who arrived at the station with the STS-119 crew. Credit: NASA


On the Net:

• President Obama talks with Station Crews

• STS-119 latest news: sas.ivv.nasa.gov • mynasa1.nasa.gov/forstudents • http://forum.nasaspaceflight.com
• Leading source of online space news: www.spaceflightnowplus.com • http://www.nasa.gov/topics/shuttle_station

Space.gs

Space Shuttle Discovery Crew Undocks From International Space Station, Starts Journey Home
By Space News, March 24, 2009




- After 129 days aboard the International Space Station, astronaut Sandy Magnus is headed back to Earth along with the Discovery
astronauts, who spent nearly 10 days docked to the station.




- The 10 crew members gathered in the Harmony module at 11:53 a.m. CDT for a farewell ceremony where ISS Commander Mike Fincke
thanked the Discovery crew for an outstanding mission and giving the station more power and a new crew member, Japan Aerospace
Exploration Agency astronaut Koichi Wakata. After shuttle Commander Lee Archambault led his crew back into Discovery, he and Fincke
closed the hatches between their two vehicles at 12:59 p.m.




- Discovery undocked from the ISS at 2:53 p.m. as springs pushed the shuttle out in front of the station. At a distance of 400 feet, Pilot
Tony Antonelli circled the station as the shuttle's crew and cameras captured the first look at the completed truss structure and the fourth
set of solar array wings fully deployed.




- At 4:09 p.m., the first of two separation burns was performed to move Discovery away from the station to start the journey home.
The final separation burn occurred at 4:37 p.m. If the STS-119 crew lands on the first opportunity on Saturday, 12:43 p.m. at the
Kennedy Space Center in Florida, Magnus will have spent 134 days in space, and Discovery's crew nearly 13 days in space.




- Tomorrow, the crew will wake at 5:13 a.m. and perform a late inspection of Discovery's thermal protection system using the shuttle
robotic arm and the Orbital Boom Sensor System around 9:28 a.m. This procedure will last for approximately five hours before the OBSS and
arm are then berthed in Discovery's payload bay around 2:43 p.m.




-Also Thursday, Expedition 19 Commander Gennady Padalka, Flight Engineer Michael Barratt and spaceflight participant Charles Simonyi
are on target for a Soyuz launch at 6:49 a.m. from the Baikonur Cosmodrome in Kazakhstan. They will dock with station Saturday as
Discovery ends its STS-119 mission. (more)





• Spaceflight Photos: http://wanderingspace.net

Partnership -- The Expedition 18 crew photographed the Russian segment of the International Space Station during a spacewalk on Tuesday, March 10, 2009.
During the spacewalk, Commander Mike Fincke and Flight Engineer Yury Lonchakov installed the Exposing Specimens of Organic and Biological Materials to
Open Space (Expose-R) experiment mounted on the Zvezda Service Module's the universal science platform. Image Credit: NASA





Photo: Space Shuttle above Earth

Photo from NASA's Image of the Day Gallery: http://mynasa1.nasa.gov/multimedia/imag ... /iotd.html / 2 / 3 / 4





View more than 700 NASA.gov Image of the Day features posted from 2003 to 2006: http://mynasa1.nasa.gov/multimedia/imag ... chive.html

Testing the Future

(high res.)

- The U.S. launch vehicles that will carry explorers back to the moon will be powered in part by a J–2X engine that draws its heritage from the Apollo-Saturn Program. The J-2X will power the upper stages of both the Ares I crew launch vehicle and Ares V cargo launch vehicle. Image credit: NASA (more)


The J-2X engine will power the upper stages of the Ares I and Ares V launch vehicles. Ares I is a two-stage rocket that will transport the Orion crew exploration vehicle to low Earth orbit. Ares V will enable NASA to launch a variety of science and exploration payloads, as well as key components needed to go to the moon and later to Mars.

This image shows the rocket engine exhaust nozzles, which are being designed and tested at NASA's Marshall Space Flight Center. Engineers at the center are testing the nozzle to ensure that it is Center. Engineers at the center are testing the nozzle to ensure that it is strong enough to withstand uneven forces. Testing at Marshall's Nozzle Test Facility enables Pratt & Whitney Rocketdyne design engineers to apply test data to the computer analyses used to design the nozzle. Testing began in March 2008. (more)

Read more about J-2X testing and NASA's Ares rockets:
http://www.nasa.gov/mission_pages/const ... ust08.html

COMPUTATIONAL COSMOLOGY

Mapping the Universe to the Beginning of Time
From Scidacreview.org




- The cosmic microwave background, radiation left over from the Big Bang, provides scientists with clues about the early Universe and the parameters of cosmology in general. The 2006 Nobel Prize in Physics was awarded for experiments resulting in data that support the Big Bang model. Further work in this field promises to yield more discoveries about the fundamental nature of our Universe.


Understanding Our Universe -- One of the biggest questions—both literally and figuratively--since the dawn of humankind is: What is our place in the Universe? This desire to understand our place has driven scientific discovery throughout history, from the ancients Greeks and Chinese to the Aztecs and Mayans, to Copernicus and Galileo, to Sputnik and the Hubble Space Telescope. In the past century, this quest has become more focused, leading to a standard model of cosmology in which the Universe comes into existence with a Big Bang, which creates space and starts time. Detailed measurements of this cosmos suggest that the matter we can see—planets, stars, and galaxies—make up less than 5% of the Universe.

Up to one quarter of the Universe is now thought to be the invisible dark matter. The remainder is posited to be dark energy, the force driving the expansion of the Universe. The fundamental questions in modern cosmology concern the nature of the dark Universe (dark matter, and especially dark energy). What is it? How has it evolved? What does it tell us about our future? Through increasingly precise observations and experiments, we can find evidence with which to address these questions.


Spiegel Video: Planck's scan of the sky and what happend before the big bang

- One of the keys to understanding our Universe is the relic radiation from the Big Bang, known as the cosmic microwave background. The routine observations of Planck are planned to last 15 months, allowing two complete surveys of the sky.


One of the keys to understanding our Universe is the relic radiation from the Big Bang, known as the cosmic microwave background. Last scattered some 400,000 years after the Big Bang (about 14 billion years ago), the CMB provides the earliest possible image of the Universe, and encoded within this image are signatures of the fundamental parameters of cosmology. Since the CMB was first detected in 1965, a number of ground-based, balloon-, and satellite-borne experiments using increasingly precise instrumentation have been conducted to measure and characterize the CMB. Such experiments scan the sky with incredibly sensitive thermometers tuned to microwave frequencies for as long as possible. Continued...





• The Standard Hot Big Bang Model of the Universe - A Summary by David Harrison

"A variation of Big Bang cosmology is called the Bang-Bang-Bang one. If the universe is closed it will end in a Big Crunch. But the conditions of the Big Crunch are identical to the conditions of the Big Bang. Thus the end of this cycle of the universe is the beginning of the next.

In the early 1960's Huston Smith had an interview with the Dalai Lama. The Dalai Lama asked about the current status of scientific cosmological theories. Smith outlined the Steady State model, the Big Bang model, and the Bang-Bang-Bang one. The Dalai Lama remarked that of the three, the last one was closest to correct.


• Vedic cosmology - planetarium


Here is one of my favorite images of a Bang-Bang-Bang cosmology. "O King of Gods. I have known the dreadful dissolution of the universe. I have seen all perish, again and again, at the end of every cycle. At that terrible time, every single atom dissolves into the primal pure waters of eternity, whence originally all arose. Everything then goes back into the fathomless, wild infinity of the ocean, which is covered with utter darkness and is empty of every sign of animate being. Ah, who will count the universes that have passed away, or the creations that have risen afresh, again and again, from the formless abyss of the vast waters? Who will number the passing ages of the world, as they follow each other endlessly? And who will search through the wide infinities of space to count the universes side by side, each containing its Brahma, its Vishnu, and its Shiva?"

-- Vishnu, in the Brahma-vaivarta Purana from H. Zimmer, Myths and Symbols in Indian Art and Civilization. Continued...

Cygnus Loop Supernova Remnant

This 1991 image from NASA's Hubble Space Telescope captures a small section of the Cygnus Loop supernova remnant. The Cygnus Loop marks the edge of a bubble-like, expanding blast wave from a colossal stellar explosion which occurred about 15,000 years ago. Supernova remnants play an important role in stellar evolution by enriching space with heavy elements, and triggering new star formation by compressing interstellar gas.

The image shows the structure behind the shock waves in the Cygnus Loop with unprecedented clarity, allowing astronomers to compare directly the actual structure of the shock with theoretical model calculations for the first time. Besides supernova remnants, these shock models are important in understanding a wide range of astrophysical phenomena, ranging from winds in newly-formed stars to cataclysmic stellar outbursts. As the supernova blast wave slams into tenuous clouds of interstellar gas, the resulting collision heats and compresses the gas, causing it to glow. The shock acts as a searchlight by revealing the structure of the interstellar medium.

A bluish ribbon of light stretching left to right across the picture might be a knot of gas ejected by the supernova. This interstellar "bullet," traveling over three million miles per hour (5 million km), is just catching up with the shock front, which has been slowed by plowing into interstellar material. The Cygnus Loop appears as a faint ring of glowing gases about three degrees across (six times the diameter of the full moon), located in the northern constellation Cygnus the Swan. The supernova remnant is within the plane of our Milky Way Galaxy and is 2,600 light-years away.

Image credit: NASA and J.J. Hester (Arizona State University)

NASA Image: Supernova Remnant

NASA Image: Munich International Airport - Germany's second-busiest airport