A prominent star bubble. Credit: NASA / The Milky Way Project / Zooniverse
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Remember when you were a kid and blowing bubbles was such great fun? Well, stars kind of do that too. The “bubbles” are partial or complete rings of dust and gas that occur around young stars in active star-forming regions, known as stellar nurseries. So far, over 5,000 bubbles have been found, but there are many more out there awaiting discovery. Now there is a project that you can take part in yourself, to help find more of these intriguing objects.
The Milky Way Project, part of Zooniverse, has been cataloguing these cosmic bubbles thanks to assistance from the public, or “citizen scientists” – anyone can help by examining images from the Spitzer Space Telescope, specifically the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and the Multiband Imaging Photometer for Spitzer Galactic Plane Survey (MIPSGAL).
They have been seen before, but now the task is to find as many as possible in the newer, high-resolution images from Spitzer. A previous catalogue of star bubbles in 2007 listed 269 of them. Four other researchers had found about 600 of them in 2006. Now they are being found by the thousands. As of now, the new catalogue lists 5,106 bubbles, after looking at almost half a million images so far. As it turns out, humans are more skilled at identifying them in the images than a computer algorithm would be. People are better at pattern recognition and then making a judgment based on the data as to what actually is a bubble and what isn’t.
The bubbles form around hot, young massive stars where it is thought that the intense light being emitted causes a shock wave, blowing out a space, or bubble, in the surrounding gas and dust.
Eli Bressert, of the European Southern Observatory and Milky Way Project team member, stated that our galaxy “is basically like champagne, there are so many bubbles.” He adds, “We thought we were going to be able to answer a lot of questions, but it’s going to be bringing us way more questions than answers right now. This is really starting something new in astronomy that we haven’t been able to do.”
There are currently about 35,000 volunteers in the project; if you would like to take part, you can go to The Milky Way Project for more information.
The Moon rises above (below?) Earth's limb in this view from the ISS. (ESA/NASA)
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“The moon looks the same from the ISS as it does on Earth. Only we see it rise and set again and again.”
ESA astronaut André Kuipers tweeted this message earlier today, accompanied by the wonderful photo above showing a distant Moon resting along Earth’s limb. The solar panels of the docked Soyuz TMA-03M spacecraft are seen in the foreground.
André arrived at the Space Station on December 23 along with Expedition 30 crewmates Oleg Kononeko and Don Pettit.
In addition to conducting over 45 experiments for ESA, NASA and JAXA during his five months in orbit, André’s PromISSe mission will help educate children about math, science, engineering, technology, and the benefits – and challenges – of working in space.
The program will also encourage the next generation of space explorers to stay fit with the second edition of the international fitness initiative Mission X: Train Like an Astronaut.
A medical doctor, André serves as flight engineer aboard the ISS and will be highly involved in docking procedures for the new Dragon (SpaceX) and Cygnus (Orbital Sciences) capsules as part of NASA’s next-generation commercial spaceflight program.
Read ESA’s PromISSe mission blog here, and follow André Kuipers on Twitter @astro_andre for more Expedition 30 mission updates.
The Southern Cross, the Milky Way, and the Large Magellanic Cloud shine above the Atacama Large Millimeter/submillimeter Array (ALMA) as it observes on a clear night sky during its Early Science phase. Image credit: C. Padilla, NRAO/AUI/NSF
[/caption]Using the partially constructed ALMA observatory, a group of astronomers have found new evidence that helps explain how young, star-forming galaxies end up as ‘red and dead’ elliptical galaxies.
According to current galactic evolution theories, mergers of spiral galaxies are thought to explain why nearby elliptical galaxies have few young stars. Merging galaxies direct gas and dust into starburts, which are regions of rapid star formation, as well as into the central supermassive black hole at the core of the merging galaxies. As matter is piled onto a black hole, powerful jets erupt, and the region becomes a brightly shining quasar. Eventually the powerful jets emanating from the central black hole push away any potentially star-forming gas, which causes the starbursts to cease.
Astronomers have, until recently, been unable to detect enough mergers at the “jet” stage to make a definite link between the outflows and the end of starburst activity. During early science observations in 2011, ALMA became the first telescope to confirm almost two dozen galaxies at the critical, yet brief stage of galaxy evolution.
“Despite ALMA’s great sensitiviy to detecting starbursts, we saw nothing, or next to nothing – which is exactly what we hoped it would see,” said Dr. Carol Lonsdale (NRAO). Lonsdale presented the findings at the American Astronomical Society’s meeting in Austin, Texas on behalf of an international team of astronomers.
ALMA was set to look for the signature of dust warmed by star-forming regions. Half of Lonsdale’s two dozen galaxies were not visible in ALMA’s observations, and the other half very dim.
“ALMA’s results reveal to us that there is little-to-no starbursting going on in these young, active galaxies. The galaxy evolution model says this is thanks to their central black holes whose jets are starving them of star-forming gas,” Lonsdale said. “On its first run out of the gate, ALMA confirmed a critical phase in the timeline of galaxy evolution.”
Infographic showing the sequence of events that model a typical galaxy becoming a so-called "red and dead" elliptical. Lonsdale and her team found a large population of galaxies, right in the middle of this sequence, between steps d and e. Image Credit: Hopkins, et al., NOAO/AURA/NSF.
After the star-forming gas is blown away, merging galaxies no longer form new stars. Once the massive, bright, blue, and short-lived stars die out, the redder, longer-lived, lower mass stars begin to dominate the population, leading to a gas-starved galaxy taking on a redder hue. To support the gas-starvation theory, astronomers needed to observe the process at work, specifically in merging galaxies with high power jets where quasars can be found.
Lonsdale added, “The missing phase had to be among quasars that could be seen brightly in infrared and radio wavelengths — mergers young enough to have their cores still swaddled in infrared-bright dust, but old enough that their black holes were well fed and producing jets observable in the radio.”
The team’s hunt for the specific type of quasars began with NASA’s Wide-field Infrared Survey Explorer (WISE) spacecraft. The WISE data consists of millions of objects in its all-sky survey of the Universe. Lonsdale led WISE’s quasar survey team that picked out the brightest, reddest objects this infrared telescope had mapped.
Selected images from among the twenty-three quasars observed with ALMA so far in its hunt for candidate starving galaxies. Image Credit: C. Lonsdale, NRAO/AUI/NSF; ALMA (NRAO/ESO/NAOJ)
Lonsdale and her team compared the WISE data against the NRAO’s VLA Sky Survey of 1.8 million radio objects. The team then used results common to both sets of data to determine the best targets for their starburst search with ALMA. Since ALMA uses longer infrared wavelengths than WISE, Lonsdale’s team was able to make the distinction between dust warmed by starburst activity and dust heated by material falling onto the central black hole.
There are 26 more WISE quasars for ALMA to survey before Lonsdale and her team publish their results. In the meantime, Lonsdale and her team will observe these galaxies with the newly re-named Karl G. Jansky Very Large Array (VLA).
“ALMA revealed to us this rare stage of galaxy starvation, and now we want to use the VLA to focus on delineating the outflows that robbed these galaxies of their fuel,” Lonsdale said. “Together, the two most sensitive radio telescope arrays in the world will help us truly understand the fate of spiral galaxies like our own Milky Way.”
The top image shows part of the Hubble Ultra Deep Field, the region where astronomers were looking for a supernova blast. The white box pinpoints the area where the supernova is later seen. The image combines observations taken in visible and near-infrared light with the Advanced Camera for Surveys and the Wide Field Camera 3. The image at bottom left, taken by the Wide Field Camera 3, is a close-up of the field without the supernova. A new bright object, identified as the supernova, appears in the Wide Field Camera 3 image at bottom right. Credit: NASA, ESA, A. Riess (Space Telescope Science Institute and The Johns Hopkins University), and S. Rodney (The Johns Hopkins University)
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Its nickname is SN Primo and it’s the farthest Type Ia supernova to have its distance spectroscopically confirmed. When the progenitor star exploded some 9 billion years ago, Primo sent its brilliant beacon of light across time and space to be captured by the Hubble Space Telescope. It’s all part and parcel of a three-year project dealing specifically with Type Ia supernovae. By splitting its light into constituent colors, researchers can verify its distance by redshift and help astronomers better understand not only the expanding Universe, but the constraints of dark energy.
“For decades, astronomers have harnessed the power of Hubble to unravel the mysteries of the Universe,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “This new observation builds upon the revolutionary research using Hubble that won astronomers the 2011 Nobel Prize in Physics, while bringing us a step closer to understanding the nature of dark energy which drives the cosmic acceleration.”
Type Ia supernovae are theorized to have originated from white dwarf stars which have collected an excess of material from their companions and exploded. Because of their remote nature, they have been used to measure great distances with acceptable accuracy. Enter the CANDELS+CLASH Supernova Project… a type of census which utilizes the sharpness and versatility of Hubble’s Wide Field Camera 3 (WFC3) to aid astronomers in the search for supernovae in near- infrared light and verify their distance with spectroscopy. CANDELS is the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and CLASH is the Cluster Lensing and Supernova Survey with Hubble.
“In our search for supernovae, we had gone as far as we could go in optical light,” said Adam Riess, the project’s lead investigator, at the Space Telescope Science Institute and The Johns Hopkins University in Baltimore, Md. “But it’s only the beginning of what we can do in infrared light. This discovery demonstrates that we can use the Wide Field Camera 3 to search for supernovae in the distant Universe.”
However, discovering a supernova like Primo just doesn’t happen overnight. It took the research team several months of work and a huge amount of near-infrared images to locate the faint signature. After capturing the elusive target in October 2010, it was time to employ the WFC3’s spectrometer to validate SN Primo’s distance and analyze the spectra for confirmation of a Type Ia supernova event. Once verified, the team continued to image SN Primo for the next eight months – collecting data as it faded away. By engaging the Hubble in this type of census, astronomers hope to further their understanding of how such events are created. If they should discover that Type Ia supernova don’t always appear the same, it may lead to a way of categorizing those changes and aid in measuring dark energy. Riess and two other astronomers shared the 2011 Nobel Prize in Physics for discovering dark energy 13 years ago, using Type Ia supernova to plot the Universe’s expansion rate.
“If we look into the early Universe and measure a drop in the number of supernovae, then it could be that it takes a long time to make a Type Ia supernova,” said team member Steve Rodney of The Johns Hopkins University. “Like corn kernels in a pan waiting for the oil to heat up, the stars haven’t had enough time at that epoch to evolve to the point of explosion. However, if supernovae form very quickly, like microwave popcorn, then they will be immediately visible, and we’ll find many of them, even when the Universe was very young. Each supernova is unique, so it’s possible that there are multiple ways to make a supernova.”
Mars fever has gripped India. In a recent report from the Planetary Science and Exploration conference that was held in December 2011, scientists from the Indian Space Research Organization (ISRO) are making preliminary plans for a robotic mission to the Red Planet sometime next year.
The possibility of an Indian mission to Mars first came up during a brainstorming session at the Physical Research Laboratory (PRL), an affiliate of the ISRO, last March. For two days, scientists and students developed their plans and proposals for a mission to the red planet.
A Mars Mission Study Team has been established to review proposed scenarios for the future mission, and an Indian chapter of the Mars Society formed last year at IIT-Mumbai.
Viking 2's view of Mars in 1976. Image credit: NASA/courtesy of nasaimages.org
The report from the meeting last month gives a concrete look at what Indian scientists have on their Martian wish list. In all, ten instruments and experiments comprise the ultimate mission.
En route to Mars, a Mars Radiation Spectrometer (Maris) will measure and characterize background levels of charged particles in interplanetary space. This data will play a vital role in determining radiation levels facing humans going to Mars.
Once at Mars, the proposed Indian mission will focus on the Martian atmosphere.
A Probe For Infrared Spectroscopy for Mars (Prism) is designed to study the spatial and seasonal variations of atmospheric gases on Mars’ atmosphere throughout the mission’s lifetime. The Mars Exospheric Neutral Composition Analyzer (Menca) is designed to analyze the planet’s upper atmosphere-exosphere, the region roughly 400 km (248 miles) above the surface.
Specific instruments are designed to study the composition of the atmosphere. A Methane Sensor For Mars (MSM) has been proposed to detect traces of the gas in the atmosphere. Another instrument, Tis, will measure thermal emissions to help scientists generate a map reflecting the composition and mineralogy of the planet. It will also help the team monitor carbon dioxide levels.
A Plasma and Current Experiment (Pace) will assess the escape rate of the atmosphere and the structure of the “tail” this escaping atmosphere creates. Radio and microwave instruments will also be on board the spacecraft to measure the planet’s surface activity. A suite of instruments will also be on hand to detect plasma waves in the atmosphere.
Mars's atmosphere is only 1 percent as thick as Earth's. Image credit: NASA
Visual measurements are also part of the proposed mission. The Mars Color Camera (MCC) is designed to photograph the Martian surface from a highly elliptical orbit, roughly 500 km by 80,000 km (310 miles by 49,700 miles). The camera will be able to take high resolution images of the topography of the surface and map the polar caps, both of which are expected to help scientists understand surface events like dust storms.
According to ISRO scientists, the proposed mission could launch as early as November 2013, which would have the spacecraft enter into orbit around Mars in September 2014. A launch so relatively soon is appealing to many Indian scientists, many of whom argue that a mission to Mars should take priority over a mission to the Moon.
After all, India has already reached the Moon with the successful Chandrayaan-2 spacecraft. Why not keep the momentum going and aim for a new and exciting target with the next mission?
Phobos-Grunt plunged to Earth into the Pacific Ocean on Jan 15, 2012 - Crash Zone Map shows orbital track of Phobos-Grunt on Final Orbit before crashing to Earth in the Pacific Ocean west of South America on Jan 15, 2012.
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Story and Crash Zone Map updated 1 p.m. EST Jan 16
Today (Jan. 15) was the last day of life for Russia’s ambitious Phobos-Grunt mission to Mars after a desperate two month race against time and all out attempts to save the daring spaceship by firing up a malfunctioning thruster essential to putting the stranded probe on a trajectory to the Red Planet, failed.
According to the Russian news agency Ria Novosti, the doomed Phobos-Grunt spacecraft apparently plunged into the southern Pacific Ocean today, (Jan. 15) at about 12:45 p.m. EST, 21:45 Moscow time [17:45 GMT] after a fiery re-entry into the Earth’s atmosphere.
“Phobos-Grunt fragments have crashed down in the Pacific Ocean,” Russia’s Defense Ministry official Alexei Zolotukhin told RIA Novosti. He added that the fragments fell 1,250 kilometers to the west of the Chilean island of Wellington.
Universe Today will monitor the developing situation and update this story as warranted. On Jan. 16 Roscosmos confirmed the demise of Phobos-Grunt at 12:45 p.m. EST in the Pacific Ocean – during its last orbit; #1097.
Artist’s concept of Phobos-Grunt re-entry and breakup in the Earth’s atmosphere on Jan 15, 2012
The demise of the Phobos-Grunt spacecraft was expected sometime today, (Jan 15) after a fiery and destructive fall back to Earth, said Roscosmos, the Russian Federal Space Agency, in an official statement released early today before the crash.
Since the re-entry was uncontrolled, the exact time and location could not be precisely calculated beforehand. Mission Poster for the Russian Phobos-Grunt soil sample return spacecraft that launched to Mars and its moon Phobos on 9 November 2011. The mission did not depart Earth orbit when the upper stage engines failed to ignite. Credit: Roskosmos ( Russian Federal Space Agency)/IKI
The actual crash time of the 13,500 kg space probe was slightly earlier than predicted.
Roscosmos head Vladimir Popovkin had previously stated that perhaps 20 to 30 fragments weighing perhaps 400 pounds (180 kg) might survive and would fall harmlessly to Earth.
The spacecraft burst into a large quantity of pieces as it hit the atmosphere, heated up and broke apart. But the actual outcome of any possible fragments is not known at this time.
Shortly after launching from the Baikonur Cosmodrome on Nov. 9, 2011, the probe became stuck in low Earth orbit after its MDU upper stage engines repeatedly failed to ignite and send the ship on a bold sample return mission to the tiny Martian Moon Phobos.
Phobos-Grunt was loaded with over 11,000 kg of toxic propellants, including dimethylhydrazine and dinitrogen tetroxide, that went unused due to the thruster malfunction and that were expected to be incinerated during the plunge to Earth.
Frictional drag forces from the Earth’s atmosphere had gradually lowered the ship’s orbit in the past two months to the point of no return after all attempts to fire the thrusters and raise the orbit utterly failed.
The audacious goal of Phobos-Grunt was to carry out history’s first ever landing on Phobos, retrieve 200 grams of soil and bring the treasured samples back to Earth for high powered analysis that could help unlock secrets to the formation of Mars, Phobos and the Solar System.
Phobos-Grunt spacecraft being encapsulated inside the nose cone by technicians at the Baikonur Cosmodrome prior to Nov. 9, 2011 blastoff. Credit: Roscosmos
The Holy Grail of planetary science is to retrieve Martian soil samples – and scientists speculated that bits of the Red Planet could be intermixed with the soil of its mini moon Phobos, barely 15 miles in diameter.
The science return from Phobos-Grunt would have been first rate and outstanding.
It’s a sad end to Russia’s attempts to restart their long dormant interplanetary space science program.
The $165 mission was Russia’s first Mars launch in more than 15 years.
Radar image of the Russian Mars orbiter Phobos-Grunt, created with the TIRA space observation radar by researchers at the Fraunhofer Institute in Germany. One can clearly see the extended solar panels (centre) and the tank ring (bottom)
Credit: Fraunhofer FHR
Click to enlarge
Roscosmos had stated that the Atlantic Ocean – to the west of Africa – was at the center of the predicted crash zone. But nothing was certain and the probe had the possibility to crash sooner, perhaps over the Pacific Ocean or South America or later over Africa, Europe or Russia.
Roscosmos had predicted the time of the plunge to Earth to be from 12:50 p.m. EST and 1:34 p.m. EST (1750 to 1834 GMT) or 21:50 to 22: 34 Moscow time on January 15. The last orbit carried the probe over the Pacific Ocean towards South America on a northeasterly heading.
Russia enlisted assistance from ESA and the US in a bid to establish contact with the probe to reorient itself and fire up its engines for a belated journey to the Red Planet. Other than extremely brief signals the efforts proved futile and today’s Pacific plunge is the unfortunate end result.
Hopefully the Russians will not give up in despair, but rather fix the flaws and launch an exciting new Mars mission.
NASA has had better luck with their Mars mission this season.
The Curiosity Mars Science Lab rover is precisely on course to the Red Planet following the Jan 11 firing of the cruise stage thrusters for the first of up to 6 Trajectory Correction Maneuvers – read the details here
Phobos-Grunt imaged while flying over Holland on Dec 28, 2011 by astrophotographer Ralf Vandebergh. Solar panels are deployed. Credit: Ralf Vandebergh
Hubble image of a Proplyd-like object in Cygnus OB2. Credit: Z. Levay and L. Frattare, STScI
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The well known Orion Nebula is perhaps the most well known star forming regions in the sky. The four massive stars known as the trapezium illuminate the massive cloud of gas and dust busily forming into new stars providing astronomers a stunning vista to explore stellar formation and young systems. In the region are numerous “protoplanetary disks” or proplyds for short which are regions of dense gas around a newly formed star. Such disks are common around young stars and have recently been discovered in an even more massive, but less well known star forming region within our own galaxy: Cygnus OB2.
Ten times more massive than its more famous counterpart in Orion, Cygnus OB2 is a star forming region that is a portion of a larger collection of gas known as Cygnus X. The OB2 region is notable because, like the Orion nebula, it contains several exceptionally massive stars including OB2-12 which is one of the most massive and luminous stars within our own galaxy. In total the region has more than 65 O class stars, the most massive category in astronomers classification system. Yet for as bright as these stars are, Cygnus OB2 is not a popular target for amateur astronomers due to its position behind a dark obscuring cloud which blocks the majority of visible light.
But like many objects obscured in this manner, infrared and radio telescopes have been used to pierce the veil and study the region. The new study, led by Nicholas Wright at the Harvard-Smithsonian Center for Astrophysics, combines infrared and visual observations from the Hubble Space telescope. The observations revealed 10 objects similar in appearance to the Orion proplyds. The objects had long tails being blown away from the central mass due to the strong stellar winds from the central cluster similar to how proplyds in Orion point away from the trapezium. On the closer end, the objects were brightly ionized.
Yet despite the similarities, the objects may not be true proplyds. Instead, they may be regions known as “evaporating gaseous globules” or EGGs for short. The key difference between the two is whether or not a star has formed. EGGs are overdense regions within a larger nebula. Their size and density makes them resistant to the ionization and stripping that blows away the rest of the nebula. Because the interior regions are shielded from these dispersive forces, the center may collapse to form a star which is the requirement for a proplyd. So which are these?
In general, the newly discovered objects are far larger than those typically found in Orion. While Orion proplyds are nearly symmetric across an axis directed towards the central cluster, the OB2 objects have twisted tails with complex shapes. The objects are 18-113 thousand AU (1 AU = the distance between the Earth and Sun = 93 million miles = 150 million km) across making them significantly larger than the Orion proplyds and even larger than the largest known proplyds in NGC 6303.
Yet as different as they are, the current theoretical understanding of how proplyds work doesn’t put them beyond the plausible range. In particular, the size for a true proplyd is limited by how much stripping it feels from the central stars. Since these objects are further away from OB2-12 and the other massive stars than the Orion proplyds are from the trapezium, they should feel less dispersive forces and should be able to grow as large as is seen. Attempting to pierce the thick dust the objects contain and discover if central stars were present, the team examined the objects in the infrared and radio. Of the ten objects, seven had strong candidates central stellar sources.
Still, the stark differences make conclusively identifying the objects as either EGGs or proplyds difficult. Instead, the authors suggest that these objects may be the first discovery of an inbetween stage: old, highly evolved EGGs which have nearly formed stars making them more akin to young proplyds. If further evidence supports this, this finding would help fill in the scant observational details surrounding stellar formation. This would allow astronomers to more thoroughly test theories which are also tied to the understanding of how planetary systems form.
A bubbling cauldron of star birth is highlighted in this new image from NASA's Spitzer Space Telescope. Image credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA
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Thanks to the incredible infra-red imagery of NASA’s Spitzer Space Telescope, we’re able to take a look into a tortured region of star formation. Infrared light in this image has been color-coded according to wavelength. Light of 3.6 microns is blue, 4.5-micron light is blue-green, 8.0-micron light is green, and 24-micron light is red. The data was taken before the Spitzer mission ran out of its coolant in 2009, and began its “warm” mission. This image reveals one of the most active and tumultuous areas of the Milky Way – Cygnus X. Located some 4,500 light years away, the violent-appearing dust cloud holds thousands of massive stars and even more of moderate size. It is literally “star soup”…
“Spitzer captured the range of activities happening in this violent cloud of stellar birth,” said Joseph Hora of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., who presented the results today at the 219th meeting of the American Astronomical Society in Austin, Texas. “We see bubbles carved out by massive stars, pillars of new stars, dark filaments lined with stellar embryos and more.”
According to popular theory, stars are created in regions similar to Cygnus X. As their lives progress, they drift away from each other and it is surmised the Sun once belonged to a stellar association formed in a slightly less extreme environment. In regions like Cygnus X, the dust clouds are characterized with deformations caused by stellar winds and high radiation. The massive stars literally shred the clouds that birth them. This action can stop other stars from forming… and also cause the rise of others.
“One of the questions we want to answer is how such a violent process can lead to both the death and birth of new stars,” said Sean Carey, a team member from NASA’s Spitzer Science Center at the California Institute of Technology, Pasadena, Calif. “We still don’t know exactly how stars form in such disruptive environments.”
Thanks to Spitzer’s infra-red data, scientists are now able to paint a clearer picture of what happens in dusty complexes. It allows astronomers to peer behind the veil where embryonic stars were once hidden – and highlights areas like pillars where forming stars pop out inside their cavities. Another revelation is dark filaments of dust, where embedded stars make their home. It is visions like this that has scientists asking questions… Questions such as how filaments and pillars could be related.
“We have evidence that the massive stars are triggering the birth of new ones in the dark filaments, in addition to the pillars, but we still have more work to do,” said Hora.
Christmas Eve photo of the Strait of Hormuz from the International Space Station. The image of the Strait of Hormuz (center) and the Persian Gulf region was shot on Christmas Eve, 24 December 2011. 20% of the world’ s oil supply passes through the Strait every day. Iran has threatened to close the Strait to oil shipments. Note the thin atmosphere and curvature of the Earth. ISS module above. Photo Credit: NASA
[/caption]A beautiful and peaceful Christmas-time picture of The Strait of Hormuz was shot from the International Space Station (ISS) soaring some 250 miles (400 kilometers) overhead on Christmas Eve, 24 Dec 2011.
Today, the economically vital Strait of Hormuz is a ‘Flashpoint of Tension’ between Iran and the US and much of the rest of the world community because of official threats by Iranian government officials to shut the highly strategic waterway to crude oil tankers that transport the lifeblood of the world’s economy.
The timely image above was just tweeted by NASA Astronaut Ron Garan who wrote; “Interesting peaceful pic of the #StraightofHormuz #FromSpace taken on Christmas Eve (12/24/11) from the #ISS”. Garan served aboard the ISS from April to September 2011 as a member of the Expedition 27/28 crews.
The Strait of Hormuz lies at the mouth of the Persian Gulf between Iran and the Arabian Peninsula and is a major chokehold of the world’s energy consumption.
At its narrowest point, the Strait is only 34 miles (54 kilometers) wide. The vital shipping lanes span barely 2 miles (3 kilometers) in width in each direction (see maps below).
See more ISS photos of the Persian Gulf region and the Strait, below.
Image of the Strait of Hormuz and Persian Gulf region
Taken from the International Space Station on Sept. 30, 2003. United Arab Emirates, Oman and Saudi Arabia at left, Iran at right. Credit: NASA
Each and every day, about 20% of the world’s daily petroleum consumption is shipped through the extremely narrow channel on gigantic Oil tankers. Any disruption of petroleum shipments would instantly send crude oil prices skyrocketing to exhorbitant levels that could wreak havoc and rapidly lead to a worldwide economic depression and a devastating war between Iran and the US and its allies.
Red arrow indicates location of the Strait of Hormuz in relation to the Arabian Peninsula.
In recent days Iranian boats have approached US Naval warships at high speeds while they were heading through the Strait of Hormuz – playing a potentially deadly game of cat and mouse that could spin out of control in a single misstep, even if unintentional.
Clashes would easily disrupt the crude oil tanker shipping traffic.
Several Iranian speedboats came within about 800 yards of the US vessels in recent days as a war of words has flared over oil and Iran’s nuclear program as tensions escalate.
Video Caption: Iranian speedboats closely approach US Navy ships at high speed in the Strait of Hormuz on Jan. 6, 2012. Credit: US Dept of Defense
The US and allied fleet operates in the Gulf region to protect the oil shipments and the oil installations of a number of Arab countries including Saudi Arabia.
Persian Gulf and Strait of Hormuz from cargo bay of NASA Space Shuttle - May 27, 2000. Credit: NASA Map of Strait of Hormuz showing political boundaries and narrow maritime shipping lanes. Wikipedia
An international crew of six men from the US, Russia and Holland are currently in residence aboard the ISS running science experiments.
ISS Expedition 30 Commander and US astronaut Dan Burbank snapped gorgeous photos of Comet Lovejoy during this Christmas season – look here.
Strait of Hormuz and Persian Gulf region
Look here for dazzling photos of the ISS crossing the Moon – shot just days ago from NASA’s Johnson Space Center in Houston
Today's Journal Club is about a new addition to the Standard Model of fundamental particles.
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According to Wikipedia, a journal club is a group of individuals who meet regularly to critically evaluate recent articles in scientific literature. Being Universe Today if we occasionally stray into critically evaluating each other’s critical evaluations, that’s OK too. And of course, the first rule of Journal Club is… don’t talk about Journal Club.
So, without further ado – today’s journal article on the dissection table is about using our limited understanding of dark matter to attempt visualise the cosmic web of the very early universe.
So… dark matter, pretty strange stuff huh? You can’t see it – which presumably means it’s transparent. Indeed it seems to be incapable of absorbing or otherwise interacting with light of any wavelength. So dark matter’s presence in the early universe should make it readily distinguishable from conventional matter – which does interact with light and so would have been heated, ionised and pushed around by the radiation pressure of the first stars.
This fundemental difference may lead to a way to visualise the early universe. To recap those early years, first there was the Big Bang, then three minutes later the first hydrogen nuclei formed, then 380,000 years later the first stable atoms formed. What follows from there is the so-called dark ages – until the first stars began to form from the clumping of cooled hydrogen. And according to the current standard model of Lambda Cold Dark Matter – this clumping primarily took place within gravity wells created by cold (i.e. static) dark matter.
This period is what is known as the reionization era, since the radiation of these first stars reheated the interstellar hydrogen medium and hence re-ionized it (back into a collection of H+ ions and unbound electrons).
While this is all well established cosmological lore – it is also the case that the radiation of the first stars would have applied a substantial radiation pressure on that early dense interstellar medium.
So, the early interstellar medium would not only be expanding due to the expansion of the universe, but also it would be being pushed outwards by the radiation of the first stars – meaning that there should be a relative velocity difference between the interstellar medium and the dark matter of the early universe – since the dark matter would be immune to any radiation pressure effects.
To visualize this relative velocity difference, we can look for hydrogen emissions, which are 21 cm wavelength light – unless further red-shifted, but in any case these signals are well into the radio spectrum. Radio astronomy observations at these wavelengths offer a window to enable observation of the distribution of the very first stars and galaxies – since these are the source of the first ionising radiation that differentiates the dark matter scaffolding (i.e. the gravity wells that support star and galaxy formation) from the remaining reionized interstellar medium. And so you get the first signs of the cosmic web when the universe was only 200 million years old.
Higher resolution views of this early cosmic web of primeval stars, galaxies and galactic clusters are becoming visible through high resolution radio astronomy instruments such as LOFAR – and hopefully one day in the not-too-distant future, the Square Kilometre Array – which will enable visualisation of the early universe in unprecedented detail.
So – comments? Does this fascinating observation of 21cm line absorption lines somehow lack the punch of a pretty Hubble Space Telescope image? Is radio astronomy just not sexy? Want to suggest an article for the next edition of Journal Club?
