Ian O'Neill, Author at Universe Today

December 9, 2008December 24, 2015 by Ian O'Neill

Carbon Dioxide Detected on Exoplanet HD 189733b

Artist's impression of a transiting exoplanet (ESA - C.Carreau)

[/caption]The Hubble Space Telescope has detected carbon dioxide on a planet orbiting another star. The star in question is HD 189733 (also known as V452 Vulpeculae, a variable star designation), a binary system over 60 light years away, and the planet is approximately the size of Jupiter (called HD 189733b). The exoplanet is already known to contain water and methane molecules from previous Hubble and Spitzer campaigns, but this is the first time CO₂ has been discovered.

But why all the fuss? CO₂ is another chemical marker for the existance of life. But HD 189733b isn’t a candidate planet for the search for life. After all, this “hot Jupiter” will not be hospitable to the development of even the most basic lifeforms (life as we know it in any case). This discovery is ground-breaking in that CO₂ can be sensed on a planet many light years from Earth…

“The carbon dioxide is kind of the main focus of the excitement, because that is a molecule that under the right circumstances could have a connection to biological activity as it does on Earth,” said Mark Swain of NASA’s Jet Propulsion Laboratory. “The very fact that we’re able to detect it, and estimate its abundance, is significant for the long-term effort of characterizing planets both to find out what they’re made of and to find out if they could be a possible host for life.”

Indeed, it wasn’t only carbon dioxide that was found; carbon monoxide was also detected in the exoplanet’s atmosphere. But the fact that CO₂ is a “tracer” for life and it has been detected on a planet other than a planet known to contain life (Earth) is incredibly significant. As time goes on, observation techniques advance, it is hoped small rocky bodies will be observed. If this can be done, an Earth-like planetary survey can be carried out.

Earth atmospheric molecules detected by Venus Express (ESA)

In fact, ESA’s Venus Express was recently used to characterize what Earth looks like from a distant vantage point, providing astronomers and future extraterrestrial hunters with a model that can be used when observing distant star systems. If a planet, with a similar chemical composition to that of the Earth is discovered, it would become a prime candidate for harbouring alien life.

So how did Hubble detect CO₂ on HD 189733b? Through a spectroscopic analysis of the infrared radiation being emitted by the hot planet, Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) spotted an abundance of CO and CO₂. Certain molecules in the exoplanet’s atmosphere absorb certain wavelengths of infrared light, leaving a spectroscopic “fingerprint” in the light detected by Hubble.

This kind of campaign is best carried out on star systems with their ecliptic plane seen edge-on to the Earth. This means the orbit of the exoplanet carries it behind the parent star and then infront of it. HD 189733b transits (or eclipses) its parent star every 2.2 days and then orbits behind the star. This is an ideal situation as astronomers are able to measure the emission from the star (when the line of sight to the exoplanet is blocked by the star) and use those measurements to subtract from spectroscopic analysis of the exoplanet. This technique isolates the exoplanet emission making it possible to analyse the chemical composition of its “day-side” atmosphere.

“We’re starting to find the molecules and to figure out how many of them there are to see the changes between the day side and the night side,” Swain said.

All these developments by Hubble will aid the future of exoplanet studies. In 2013, NASA’s James Webb Space Telescope will be launched to look out for “super-Earth” exoplanets (i.e. rocky planets larger than Earth), observing in near-infrared wavelengths. Therefore, the carbon dioxide discovery in the atmosphere of HD 189733b helps astronomers refine techniques to detect yet another tracer for life…

Source: HubbleSite

December 8, 2008December 24, 2015 by Ian O'Neill

Hubble’s Early Festivities: Imaging the M13 Globular Cluster “Snow Globe”

The hundreds of thousands of stars orbiting inside the globular cluster M13 (HST/NASA)

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This image is one of the latest views from the Hubble Space Telescope, closely resembling a toy snow globe. In this case, over a hundred thousand glittering stars are the little faux snow flakes and the cluster’s globular structure is the glass sides. The cluster of interest is M13, located over 25,000 light years away, measuring 150 light years across (that’s 0.15% the diameter of our galaxy). Although very pretty (and very festive), there are some interesting things going on inside this little cluster of stars…

The Empire Strikes Back. Globular clusters impart their wisdom to astronomers. Well, the connection was there for me anyway... — Yoda imparts his wisdom to Luke in Star Wars: The Empire Strikes Back. Globular clusters impart their wisdom to astronomers. *Well, the connection was there for me anyway*...

Globular clusters are very common, and many are known to surround our Milky Way galaxy. Over 150 ‘small’ clusters have been observed in our galaxy’s halo acting like cosmic artefacts; the stars contained within clusters like M13 are thought to be amongst the oldest known in the Universe. These clusters in the Milky Way halo are thought to have formed well before any stars existed in today’s Milky Way spiral disk. So these small, old clusters have some wisdom to impart on today’s astronomers as to the ancient history of our galaxy (why does Yoda from Star Wars spring to mind?).

The stars within M13 are predominantly old red giants that have expanded well beyond their original diameters and cooled significantly. These stars are stuck, gravitationally bound, orbiting a common point in the centre of the cluster’s mass. However, occasionally, as the centre of M13 is so densely packed, the old stars can stray too close, colliding, and creating a new type of star known as a “blue straggler”.

Blue stragglers appear off the main sequence of the Hertzsprung-Russell diagram (source)

Blue stragglers are formed when the gas from one star is siphoned off by another. This rejuvenates one of the stars, heating it up significantly. This phenomenon has mystified astronomers for a long time as young, blue stars were observed hiding inside clusters of old, red stars. Only recently has this collision mechanism been put forward as a possible explanation to the appearance of “young”, hot stars inside globular clusters like M13.

Putting snow globes, Yoda and blue stragglers to one side, the stunning image at the top of this post comprises of several archival observations from Hubble’s Wide Field Planetary Camera 2 and Advanced Camera for Surveys. Four separate campaigns from November 1999, April 2000, August 2005 and April 2006 were used.

What a great picture to start getting into the Christmas holiday spirit with…

Source: Space.com

December 8, 2008December 24, 2015 by Ian O'Neill

Powerful Rivers of Gas Imaged Around Star-Forming Swan Nebula

An infrared view of M17 (the Swan Nebula), a turbulent star-making cloud. (NASA/JPL-Caltech/Univ. of Wisc.)

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The turbulent and dynamic Swan Nebula (M17) has been imaged by NASA’s Spitzer Space Telescope, producing the clearest view yet of the star-forming region. Within the twisted cloud of gas and dust, violent stellar winds constantly blast the medium, generating flows around stars, creating vast bow shocks. A few massive stars in the centre of M17 are the main source of the relentless stellar “rivers” of gas, immersing smaller stars in the the flow, acting like stationary rocks on a riverbed…

This new observing campaign by Spitzer (an infrared telescope that has been in Earth orbit since 2003, and is expected to be operational until 2009), has imaged the M17 nebula with unprecedented clarity. Although it is a known fact that stellar winds inside star-forming regions generate dynamic features such as bow shocks, you cannot put a price on actually seeing these structures in an infrared image (pictured top). From analysis of these Spitzer results, Matt Povich of the University of Wisconsin has published a paper describing these new findings in the December 10th issue of the Astrophysical Journal.

“The stars are like rocks in a rushing river,” said Povich when describing the scene. “Powerful winds from the most massive stars at the center of the cloud produce a large flow of expanding gas. This gas then piles up with dust in front of winds from other massive stars that are pushing back against the flow.”

The Swan Nebula can be found in the constellation of Sagittarius, some 6000 light years away. It is a very active star-forming cloud where powerful stellar winds are eroding away the dust, clearing the region. Driving this mechanism are a group of massive stars exceeding 40 times the mass, and 100,000–1 million times the brightness, of the Sun. The stellar winds bullying smaller stars and blowing away the clouds of dust in the middle of the nebula have flow velocities exceeding 7.2 million km/hr (4.5 million mi/hr). To put this in perspective, the fast solar wind (the fastest component of our Sun’s two-component solar wind) reaches a maximum velocity of 2.8 million km/hr (1.7 million mi/hr); the stellar winds inside the Swan are 2.5 times more powerful.

So what’s the result of this powerful stellar wind engine in M17? A very obvious cavity is created inside the nebula, a process thought to spark the birth of new stars. This stellar nursery is fuelled by the compression of the edge of the cavity, producing bow shocks around anything that is relatively stationary (i.e. other stars). The direction of the bow shocks provide information about the direction of the stellar winds.

Povich studies another star forming region called RCW 49 in addition to M17, picking out the glowing gases generated inside the shock fronts maintained by the flow of stellar flows. Spitzer turns out to be the perfect tool to peer deep into nebulae, picking out the infrared emissions from bow shocks, mapping them.

“The gas being lit up in these star-forming regions looks very wispy and fragile, but looks can be deceiving,” co-author Robert Benjamin added. “These bow shocks serve as a reminder that stars aren’t born in quiet nurseries but in violent regions buffeted by winds more powerful than anything we see on Earth.”

Further observation campaigns like this one will ultimately help astronomers understand how stellar systems, like our Solar System, form out of the violence of stellar birth.

Source: NASA, Physorg.com

December 7, 2008December 24, 2015 by Ian O'Neill

Cheers! Japanese Brewery Produces Space Beer… But What’s the Point?

What could be more premium than space beer? (Sapporo Breweries)

[/caption]For the first time, beer brewed totally from barley grown in space can be enjoyed on terra firma. The Japanese-owned Sapporo Brewery is one of the oldest beer producers in the nation, so it seems fitting that the company would want to diversify into the next frontier. Although the beer wasn’t actually brewed in space, the barley ingredient was grown there. Through a joint program between Sapporo, the Russian Academy of Science and Okayama University in Japan, the small amount of barley was grown on board the ISS as part of a project to research the cultivation of foodstuffs in Earth orbit.

100 litres of Space Beer has been produced as a result of the successful microgravity barley farming effort, and a lucky 60 people will have the exclusive chance to taste the beer in Tokyo next month. Unfortunately, the Space Beer is not yet commercially available, so put that pint glass away…

Back in May, I was very excited to write about the first space beer brewing success, and Sapporo’s plans to manufacture 100 bottles of beer brewed from barley grown in space. However, my excitement quickly dissipated when I realised astronauts wouldn’t actually be drinking a cool one in orbit, and I became even less impressed when it turned out that the vast majority of the world wouldn’t actually have a chance of tasting it (unless, of course, you are in Tokyo and win the Sapporo space beer tasting lottery in January).

On further inspection, the prospect of drinking any carbonated product in microgravity becomes very unappealing. After all, bubbles don’t rise through a beer to form a nice head of foam in space; the bubbles remain suspended in the liquid. When you swallow the weightless mix of beer and CO₂ you have the rather antisocial “wet burp” scenario to contend with, making you very uncomfortable and extremely unpopular with your crewmates. Drinking and driving the Shuttle isn’t an option, and that’s not because flying a spaceship whilst intoxicated is a bad idea. It’s because you’d have a hard job keeping beer in your stomach and not all over the cabin. Ewww.

So, space beer is best served at 1-G, on Earth, and the managing director for strategy at Sapporo Breweries is very excited about how special this brewing effort is. “There’s really no beer like it because it uses 100 per cent barley. Our top seller is the Black Label brand, using additional ingredients such as rice. This one doesn’t, and is really a special beer,” said Junichi Ichikawa.

So what’s the point? Is this just a marketing gimmick, or does it have a purpose? I’m sure Sapporo are very impressed with this achievement, but what sets Space Beer apart from the stuff I’ll be drinking down the pub later?

As Ichikawa mentions, the barley used is only space produce, and there are no other ingredients (such as rice). However, I think we should ask whether there are plans to use water samples from the brand new urine recycler STS-126 installed during Space Shuttle Endeavour’s “home improvements” mission in the brewing process. I think this would make Space Beer more complete (besides, recycled wee tastes pretty good. Apparently).

The science behind growing stuff in space is also a great achievement as barley was one of several types of plant to be grown in orbit. Wheat, lettuce and peas were also grown earlier in the year and harvested. There are also plans to grow potatoes in space. All these projects aid the future of manned space travel; once we can sustain ourselves by cultivating our own produce, the dependence on Earth slowly diminishes. The operations on the ISS are a testament to these endeavours, and growing seeds and vegetables in orbit, along with recycling waste water is a tremendous achievement. Also, there appears to be no discernible difference in the DNA of plants grown in space when compared with those grown on Earth (in which case I’d expect no difference in taste between Space Beer and local pub beer anyway).

If you read the last paragraph and linked the future plans to grow potatoes in space with another alcoholic beverage, Cosmonaut Boris Morukov (who spent 11 days on the ISS) has a sobering message for any space man or woman wanting to set up their own distillery to get around the “wet burp” issue: “I think we would try to grow potatoes as food, not for vodka production.”

That said, where mankind goes, alcohol is sure to follow, it’s only a matter of time when we start seeing space bars popping up in orbit, on the Moon and Mars (especially if space tourism becomes a major industry)…

Original source: Telegraph, Sapporo

December 6, 2008December 24, 2015 by Ian O'Neill

Constellation Development Pushes Ahead: Rocket Test Fire, Component Assembly

The solid rocket test fire on Thursday, and the Ares rocket patch (NASA/Spaceflight Now)

[/caption]Despite being the subject of some bad news of late, development of the Ares rocket system and Orion crew module pushes ahead. In the Utah Desert on Thursday, the oldest ever Shuttle engine was tested. The seven-year old rocket (two years past its “guarantee”) performed a 123 second burn, simulating how long it would be in use during an optimal Shuttle launch. You may be asking, what does this have to do with Ares? Data from the Shuttle engine tests will be applied to the design of the Ares 1 rocket system, aiding engine nozzle design and boosting the robustness of the future Constellation Project. Environmental change measurements caused by pressure and sound during the firing will also be assessed.

While the Utah Desert rumbles with the sound of rockets, over at NASA’s Langley Research Center, in Hampton, Virginia, the Orion crew module and tower-like launch abort system simulators are rapidly being constructed toward the goal of full-scale Ares I-X atmospheric tests in 2009…

NASA Langley technicians work to attach the external panels for the Ares I-X crew module simulator (NASA/Sean Smith)

“This test is an example of the aggressive testing program NASA pursues to assure flight safety,” said David Beaman, manager of the Reusable Solid Rocket Booster Project Office at NASA’s Marshall Space Flight Center, about Thursday’s rocket test in the Utah Desert. “It also allows us to gather information on how motors with different ages perform.”

These are significant tests for NASA, as the space agency certifies the use of the reusable shuttle solid rocket engines for five years past the date of manufacture. This most recent test was carried out on a seven-year old shuttle engine, and it appeared to function exactly as it should, if not better. This test was ground-breaking as the engine used was the oldest of its kind to be ignited.

During a shuttle launch, each solid rocket booster generates an average thrust of 2.6 million pounds for 123 seconds. The seven-year old engine surpassed this average, generating 3.3 million pounds for slightly over two minutes. The data from this test firing will be used in the continuing development of the Ares I engine and rocket nozzle.

Development of the Constellation Program doesn’t stop at exciting rocket tests, the Orion crew module is slowly taking shape too. The next hurdle for NASA engineers is to prepare Orion for full-scale launch tests beginning in 2009, including more work on assembling the Orion pad launch-abort simulator. The two-minute full-scale launches will carry an Ares test vehicle (called the Ares I-X) to an altitude of 25 miles to test the first stage performance and first stage separation, plus the parachute recovery system.

Kevin Brown, project manager for the Ares I-X Crew Module/Launch Abort System (CM/LAS) project commented on the complexity of the task in hand, saying a lot of people from NASA and external contractors are working in tandem to arrive at a common goal, on schedule. “We have a team doing fabrication and assembly work in conjunction with an off-site contractor, and we have another team readying to install about 150 sensors once the crew module and launch abort tower are completed,” he said.

All going well, next years tests will be successful, acting as a key stepping stone toward the first crewed launch to the International Space Station in 2015 and then carrying explorers to the Moon in 2020…

Sources: Spaceflight Now, Science Daily

December 6, 2008December 24, 2015 by Ian O'Neill

Exploding Colorado Fireball, 100 Times Brighter than the Moon (Video)

Cloudbait Observatory all-sky camera image of the bright explosion on Dec. 6th at 1:28 am MST. No larger image available (Chris Peterson)

[/caption]Last night, the Colorado skies played host to a dazzling fireball event. The meteor blasted through the atmosphere, detonated and outshone the Moon by 100 times. It is therefore expected that there were many eyewitnesses, and the Cloudbait Observatory (5 km north of the town of Guffey, CO) is appealing to people to report their accounts of the fireball. Fortunately, the observatory managed to capture an all-sky camera video of the early morning explosion.

The Colorado fireball comes shortly after a similar event over Canada on November 20th, where over two dozen meteorite fragments have been recovered from agricultural land. We wait in anticipation to see if this huge Colorado fireball produced any similar fragments, but eyewitness accounts will be critical to aid such a search…

In the early hours of this morning, a large explosion dominated the Colorado skies. It was yet another large meteor ploughing through the atmosphere, ending its journey in an energetic detonation. Fortunately this event didn’t suffer from the same affliction the Sudan 2008 TC3 meteoroid impact back on October 7th (i.e. lack of observers), and put on a show much like last month’s Saskatchewan fireball (and the October Ontario meteor). All in all, North America is having a great meteor season with no lack of observers, eye witnesses and all-sky cameras.

Discussing last night’s Colorado fireball, astronomer Chris Peterson describes the event: “In seven years of operation, this is the brightest fireball I’ve ever recorded. I estimate the terminal explosion at magnitude -18, more than 100 times brighter than a full Moon.”

Video of the Colorado fireball (Chris Peterson)

Peterson was using video recorded by Cloudbait Observatory’s all-sky camera, dedicated to meteor spotting, when the surprise magnitude -18 burst lit up the skies.

Although the all-sky camera caught the fireball in the act, more information is needed about its location and altitude. There is every possibility that this fireball produced fragments that landed on the surface (much like last month’s Canadian fireball). For meteorite hunters to find these pieces, eye-witnesses need to contact the Cloudbait Observatory to file their reports.

Additional details of the event (from Cloudbait):
* Camera name: Cloudbait (map)
* Camera description: Cloudbait Observatory
* Camera coordinates: N38.786111 W105.483611
* Camera altitude: 2768 meters
* Total events for this site: 15906
* Event time: 2008-12-06 01:06:28 MST
* Image coordinates: (0.407,0.251) – (0.516,0.179)
* Azimuth: 79.8 – 117.9
* Altitude: ???
* Approximate duration: 1.0 seconds (28 video frames)
* Fireball: Yes

Source: Space Weather

December 5, 2008December 24, 2015 by Ian O'Neill

Report: Early Warning System Needed for LHC

Replacement parts for the LHC arrived over the weekend. Repair costs are thought to top £14 million ($20 million) (CERN)

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The replacement parts for the damaged components of the Large Hadron Collider (LHC) are arriving, and cautious estimates push the recommissioning date back to July 2009. We now know the repair job will cost several million dollars (£14 million according to a recent report) and scientists have identified the cause of the September 19th quench that kick-started an explosive helium leak, buckling and ripping the heavy supercooled magnets from their mounts. But how can this be avoided in the future? After all, the LHC is the most complex experiment ever constructed, there are a huge number of variables that could spell disaster when the LHC is switched back on again. The “S34 Incident” was triggered by a small electrical fault, what can prevent this from happening in the future?

According to the official report, the LHC requires an additional “early warning system” that will be tailored to detect small electrical shorts, hopefully shutting the system down before any further damage to the LHC blocks the search for the Higgs boson again…

It looks like official reports are being published thick and fast. Yesterday, I reported on two CERN reports that contained further details behind the problems faced by the engineers and physicists working on the repair of the LHC. One report suggested that it was an option to push back the date of LHC commissioning until 2010, whereas the other identified July 2009 as a good date to begin circulating protons once more. Now, a BBC news item has exposed some more facts behind the future of the LHC, indicating an early warning system is being considered to prevent an accident like the S34 Incident from happening again.

Obvious buckling of the accelerator magnets (CERN)

The incident, known as a “quench”, was caused by an electrical short between two of the 1200 electromagnets that make up the ring of the particle accelerator. This seemingly small fault was anything but; it initiated the rapid release of a tonne of helium, buckling and breaking the magnets between Sectors 3-4. Describing what happened, LHC project leader Professor Lyn Evans said, “Basically, they have been pulled off their feet and the interconnects have been broken.”

The electrical fault occurred right at the end of the commissioning process, even after the first protons had circulated around the long accelerator ring on September 10th. At the time, the LHC had seven of its eight sectors powered up to full energy, but the quench occurred right at the end of the process. “We are extremely disappointed, especially as we had already commissioned seven of the eight sections of the LHC up to full energy,” Evans said. “This was the last sector to be commissioned and this was really the very last electrical circuit. I must say it felt like a real kick in the teeth.”

If the experiments had continued as planned, scientists would be analysing the ground-breaking particle collision data by now, but it looks like CERN will be taking an even more cautious approach form here on in. “You can think of the LHC as a Formula 1 racing car. It’s a complex tool, a complex machine,” commented Dr Francisco Bertinelli, one of the engineers repairing the magnets. “We will not run it from zero to top speed over one afternoon. We will build up our confidence and lower our risks.”

Generally, although frustrated, scientists are very excited about the future for the LHC. Prof. Tejinder Verdee of Imperial College London reminds us why this is only a minor glitch in the grand scheme of things: “This science has the potential to alter the way we see nature and the way nature operates at a fundamental level so this potential still remains, albeit a few months delayed. The great science is still out there ahead of us, which is greatly motivating.”

The unravelling of the fabric of the Universe has just been delayed and the physics revolution can wait a few more months…

Source: BBC

December 5, 2008December 24, 2015 by Ian O'Neill

First Images Emerge of Damage to the LHC, Replacements Arrive

A series of problems forced LHC shutdown (CERN/LHC)

[/caption]On September 19th, CERN announced that the Large Hadron Collider had suffered a major incident, known as a “quench”. An electrical short between two of the superconducting magnets had kick-started a helium coolant leak inside the tunnels housing the accelerator ring. The quench caused the magnets to rapidly heat up, severely damaging them. The violent release of coolant ripped equipment from their concrete anchors, ensuring a huge repair operation would need to be carried out. However, it was a while before engineers were able to access the damage and the news wasn’t good: The LHC would be out of commission until the spring of 2009 at the earliest. That was such a sad day.

The first replacement magnet for sector 3-4 arrived at CERN last Saturday (CERN)

Late last month, CERN Director-General Robert Aymar gave a presentation to the 84th Plenary Meeting of the European Committee for Future Accelerators, showing the first public images of the quench aftermath, an accident that has become known as the “S34 Incident”.

In addition to these images, there are suggestions that there may be no particle collisions next year. Although the most recent report doesn’t appear to back up these plans, and replacement parts have started to arrive at the facility (above), it looks like the first collisions probably won’t happen until July 2009 at the earliest (that’s four months later than previously estimated)…

Obvious damage to concrete, where a magnet has been lifted off its mount (the red boxes) that secured it to the floor (CERN)

It looks like the September 19th quench between Sectors 3-4 of the LHC ring is now being referred to as the “S34 Incident“. And what an incident it was. Fortunately nobody was injured during the quench, but the LHC wasn’t so lucky. For a rundown of the official account of the S34 Incident, I’ll hand over to Robert Aymar’s November 28th presentation (page 15):

Within the first second, an electrical arc developed and punctured the helium enclosure, leading to release of helium into the insulation vacuum of the cryostat. The spring-loaded relief discs on the vacuum enclosure opened when the pressure exceeded atmospheric, thus relieving the helium to the tunnel. They were however unable to contain the pressure rise below the nominal 0.15 MPa absolute in the vacuum enclosures of subsector 23-25, thus resulting in large pressure forces acting on the vacuum barriers separating neighboring subsectors, which most probably damaged them. These forces displaced dipoles in the subsectors affected from their cold internal supports, and knocked the Short Straight Section cryostats housing the quadrupoles and vacuum barriers from their external support jacks at positions Q23, Q27 and Q31, in some locations breaking their anchors in the concrete floor of the tunnel. The displacement of the Short Straight Section cryostats also damaged the “jumper” connections to the cryogenic distribution line, but without rupture of the transverse vacuum barriers equipping these jumper connections, so that the insulation vacuum in the cryogenic line not degrade.

–Robert Aymar, Status of CERN Activities, page 15.

The first image (pictured above) clearly shows the extent of the concrete damage that occurred during the huge pressure forces generated by the leaking helium, ripping the electromagnets off their supports (the red boxes in the photo) and shattering the floor.

In this second image, the extent of the damage is pretty clear. Assuming the accelerator beam-line used to be straight (unfortunately, there is no “before” picture), the violent displacement of a huge magnet (weighing several tonnes) is obvious.

Later in the presentation, Aymar points out that 5 quadrupole and 24 dipole magnets need to be repaired and around 57 magnets have to be removed to be cleaned. This will be a huge task, one that will last many months. According to one eagle-eyed blogger at High Energy PhDs, a previous report presented a few days before the Aymar report signalled that there may be no high energy particle collisions until 2010. Jorg Winnenger outlined two possibilities for the LHC: 1) Partial operations in 2009, allowing only low-energy particle acceleration to await full-scale repairs through the 2009-10 winter shutdown, or 2) Forget 2009 operations and work toward full-scale experiments in 2010. Aymar’s more recent report did not mention these scenarios, simply stating, “the LHC will restart operation in the next spring.”

Early progress: replacement parts were inspected at CERN over the weekend (CERN)

This might be a little optimistic, as other quarters are signalling a July 2009 “cool-down” before operations can begin.

Judging by the mixed signals, we’ll have to wait patiently until it is clear as to when the LHC is expected to recover. Either way, it will be a long, painstaking and expensive task that needs to be completed as soon as possible. I really hope we don’t have to wait until 2010 until restart.

Good luck to all involved in the LHC repairs.

Sources: US/LHC Blog, CERN Photos, Stephanie Majewski, High Energy PhDs

December 3, 2008December 24, 2015 by Ian O'Neill

Swift Detects X-Ray Emissions from Comets

Swift's Ultraviolet/Optical Telescope (UVOT) captured Comet 73P/Schwassmann-Wachmann 3's fragment C as it passed the famous Ring Nebula (oval, bottom) on May 7, 2006 (NASA)

[/caption]Things appeared to get a little strange in the field of X-ray astronomy when the NASA/ESA ROSAT observatory started seeing emissions from a series of comets. This discovery in 1996 was a conundrum; how could X-rays, more commonly associated with hot plasmas, be produced by some of the coldest bodies in the Solar System? In 2005, NASA’s Swift observatory was launched to look out for some of the most energetic events in the observable Universe: gamma-ray bursts (GRBs) and supernovae. But in the last three years, Swift has also proven itself to be an expert comet hunter.

If X-rays are usually emitted by multi-million Kelvin plasmas, how can X-rays possibly be generated by comets composed of ice and dust? It turns out there is an interesting quirk as comets interact with the solar wind within 3AU from the solar surface, allowing instrumentation designed to observe the most violent explosions in the Universe to also study the most elegant objects closer to home…

“It was a big surprise in 1996 when the NASA-European ROSAT mission showed that comet Hyakutake was emitting X-rays,” said Dennis Bodewits, NASA Postdoctural Fellow at the Goddard Space Flight Centre. “After that discovery, astronomers searched through ROSAT archives. It turns out that most comets emit X-rays when they come within about three times Earth’s distance from the sun.” And it must have been a very big surprise for researchers who assumed ROSAT could only be used to glimpse the transient flash of a GRB or supernova, possibly spawning the birth of black holes. Comets simply did not feature in the design of this mission.

However, since the launch of another GRB hunter in 2005, NASA’s Swift Gamma-ray Explorer has spotted 380 GRBs, 80 supernovae and… 6 comets. So how can a comet possibly be studied by equipment intended for something so radically different?

As comets begin their death-defying sunward orbit, they heat up. Their frozen surfaces begin to blast gas and dust into space. Solar wind pressure causes the coma (the comet’s temporary atmosphere) to eject gas and dust behind the comet, away from the Sun. Neutral particles will be carried away by solar wind pressure, whereas charged particles will follow the interplanetary magnetic field (IMF) as an “ion tail”. Comets therefore can often be seen with two tails, a neutral tail and an ion tail.

This interaction between the solar wind and comet has another effect: charge exchange.

Energetic solar wind ions impact the coma, capturing electrons from neutral atoms. As the electrons become attached to their new parent nuclei (the solar wind ion), energy is released in the form of X-rays. As the coma can measure several thousand miles in diameter, the comet atmosphere has a huge cross section, allowing a vast number of these charge exchange events to occur. Comets suddenly become significant X-ray generators as they get blasted by solar wind ions. The total power output from the coma can top a billion Watts.

Charge exchange can occur in any system where a hot stream of ions interact with a cooler neutral gas. Using missions such as Swift to study the interaction of comets with the solar wind can provide a valuable laboratory for scientists to understand otherwise confusing X-ray emissions from other systems.

Source: Physorg.com

December 1, 2008December 24, 2015 by Ian O'Neill

Old Space Observatory Spare Parts to Search for Dirty Bombs

The Compton Gamma Ray Observatory shortly after deployment by shuttle Atlantis (STS-37) on April 5th, 1991 (NASA)

[/caption]From 1991 to 2000, the Compton Gamma Ray Observatory dominated the search for the largest explosions ever observed in the cosmos: gamma-ray bursts (or GRBs). Unfortunately after nearly a decade of highly successful observations, June 4th 2000, NASA made the unpopular decision to de-orbit the observatory in response to a mechanical failure on the spacecraft (despite protests by some scientists, pointing out that the observatory could have continued operations).

To one scientist, Jim Ryan, the demise of the project he had tirelessly worked on since 1984 was a hard pill to swallow. However, in a surprise turn of events, the US Department of Energy tracked down Ryan and asked whether his research could be applied a little closer to home. In a flash of inspiration, the scientist realised spare parts left over from the Compton Gamma Ray Observatory could be used to pinpoint emissions from a potential “dirty bomb”, possibly providing security services with an early warning capability against a radioactive terrorist attack…

Although a dirty bomb has never been detonated and remain a speculative means by terrorists to cause maximum disruption to a populated area, the Department of Energy considers the threat to be very real. This is probably because a small amount of radioactive material could be used in the construction of a relatively cheap conventional bomb and plans by groups to use such weaponry have been uncovered in the past. The key power of a dirty bomb (otherwise known as a “radiological dispersal device”) isn’t the immediate health risk to a local population (apart from the obvious damage that could be caused by the conventional explosives used in the device), it is the lasting fear, panic and economic damage such a terror attack could cause. The residual radiation left over from a dirty bomb is of course a concern, but studies show that it is the psychological damage of such an attack that would have the greater effect.

So, the Department of Energy gave Dr Ryan a call to ask whether his work at the University of New Hampshire’s Space Science Center could be used to seek out radioactive devices. At the time, he was working on an instrument to be sent within the orbit of Mercury to detect low energy neutrons being emitted from the Sun. It just so happened that the neutron energy range matched that of the emission from plutonium.

“You don’t have to be an astrophysicist to see the connection,” Ryan commented on the government interest in using his techniques to search for nuclear devices on Earth.

However, during a visit to a National Guard exercise on Cape Cod, Jim Ryan was inspired by another space mission. The exercise carried out last year was to test security agent’s ability to track down dirty bombs (not nuclear weapons containing plutonium). Dirty bombs emit a different type of radiation (not the low energy neutrons emitted from a plutonium device), and Ryan realised that parts from his old and beloved Compton Gamma Ray Observatory may be resurrected to help serve national security tasks. Rather than manually scanning suspect radioactive devices with a hand-held Geiger counter, the gamma ray radiation can be detected at a safe distance and pinpointed. The problem with Geiger counters is that although they detect gamma radiation, you have to be standing right next to the radioactive source to know where it is. Using Compton Gamma Ray Observatory techniques can make the search safer and a lot more accurate.

“It lives on and does something that is useful to society as well as pure academic science,” Ryan said during a presentation to a Homeland Security conference in May. “[It is] poetic justice,” that the techniques by the spacecraft will be re-used by the modern fight against international terrorism.

Source: Boston.com