Astronomy Cast has recently uploaded several new podcasts, and while we normally post them separately here on Universe Today, since there are a number of them arriving at once, here’s a list of the new ones:
We’ve recently had a ‘changing of the guard’ at Astronomy Cast as far as getting things posted to the AC website and getting podcasts loaded to the feed, and are now getting caught up. But as you probably know, Fraser and Pamela now record Astronomy Cast as part of Google+ Hangouts. You can watch them record live at Google+ (they usually record on Mondays at 12 noon Pacific time) or at the AstrosphereVids You Tube channel (where you can watch past Hangouts as well).
Dark matter: it’s invisible, it’s elusive, it’s controversial… and it’s everywhere — in the Universe, yes, but especially in the world of astrophysics, where researchers have been exhaustively trying to reveal its true identity for decades.
Now, scientists with the international Super Cryogenic Dark Matter Search (SuperCDMS) experiment are reporting the detection of a particle that’s thought to make up dark matter: a weakly-interacting massive particle, or WIMP. According to a press release from Texas A&M University (whose high-energy physicist Rupak Mahapatra is a principal investigator in the experiment) SuperCDMS has identified a WIMP-like signal at the 3-sigma level, which indicates a 99.8 percent chance of an actual discovery — a “concrete hint,” as it’s being called.
“In high-energy physics, a discovery is only claimed at 5-sigma or better,” Mahapatra said. “So this is certainly very exciting, but not fully convincing by the standards. We just need more data to be sure. For now, we have to live with this tantalizing hint of one of the biggest puzzles of our time.”
If this is indeed a WIMP it will be the first time such a particle has been directly observed, lending more insight into what dark matter is… or isn’t.
Notoriously elusive, WIMPs rarely interact with normal matter and therefore are difficult to detect. Scientists believe they occasionally bounce off, or scatter like billiard balls from, atomic nuclei, leaving behind a small amount of energy capable of being tracked by detectors deep underground, particle colliders such as the Large Hadron Collider at CERN and even instruments in space like the Alpha Magnetic Spectrometer (AMS) mounted on the International Space Station.
The CDMS experiment, located a half-mile underground at the Soudan mine in northern Minnesota and managed by the United States Department of Energy’s Fermi National Accelerator Laboratory, has been searching for dark matter since 2003. The experiment uses very sophisticated detector technology and advanced analysis techniques to enable cryogenically cooled (almost absolute zero temperature at -460 degrees F) germanium and silicon targets to search for the rare recoil of dark matter particles.
This newly-announced detection actually comes from data acquired during an earlier phase of the experiment.
“This result is from data taken a few years ago using silicon detectors manufactured at Stanford that are now defunct,” Mahapatra said. “Increased interest in the low mass WIMP region motivated us to complete the analysis of the silicon-detector exposure, which is less sensitive than germanium for WIMP masses above 15 giga-electronvolts [one GeVa is equal to a billion electron volts] but more sensitive for lower masses. The analysis resulted in three events, and the estimated background is 0.7 events.”
Although Mahapatra says the result is certainly encouraging and worthy of further investigation, he cautions it should not be considered a discovery just yet.
“We are only 99.8 percent sure, and we want to be 99.9999 percent sure,” Mahapatra said. “At 3-sigma, you have a hint of something. At 4-sigma, you have evidence. At 5-sigma, you have a discovery.”
“In medicine, you can say you are curing 99.8 percent of the cases, and that’s OK. When you say you’ve made a fundamental discovery in high-energy physics, you can’t be wrong.”
– Dr. Rupak Mahapatra, SuperCDMS principal investigator, Texas A&M University
The collaboration will continue to probe this WIMP sector using the SuperCDMS Soudan experiment’s operating germanium detectors and is considering using larger, more advanced 6-inch silicon detectors developed at the Texas A&M’s Department of Electrical Engineering in future experiments.
The team has detailed its results in a paper published in arXiv that eventually will appear in Physical Review Letters. Mahapatra will also announce the results today at 12 p.m. CDT in a talk at the Mitchell Institute for Fundamental Physics and Astronomy.
A victim of Hurricane Sandy provides the foreground for a stunning view of star trails over Seaside Heights, New Jersey. The Jet Star roller coaster and three other amusement rides fell into the ocean after the partial collapse of Casino Pier during Hurricane Sandy. The roller coaster sitting in the ocean became an iconic symbol of the hurricane’s destruction last fall. Astrophotographer Jack Fusco captured this absolutely incredible shot of the Jet Star under a blanket of stars on April 9, 2013. The Jet Star will soon be dismantled and removed. As one commenter on Flickr said, this shot will live on even after the roller coaster is gone.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
Spacewalkers will replace a faulty navigational aid Friday to ensure that a cargo spacecraft in June docks safely with the International Space Station.
Expedition 35 cosmonauts Pavel Vinogradov and Roman Romanenko will venture into space to remove and replace a broken retroreflector on the Russian Zvezda station module. The first spacecraft to use the new retroreflector will be the European Space Agency’s automated transfer vehicle (ATV) Albert Einstein, which is scheduled to dock with the station in June.
The ATV has a videometer on board that shoots laser beams at retroreflectors on the outside of the station. Then, the videometer analyzes the pattern of light that is returned. Based on this pattern, it navigates towards the station and in for a docking.
Albert Einstein will carry about two tons of cargo to the station, including water, oxygen, and extra fuel to boost the space station’s orbit. Tipping the scales at 44,611 pounds (20,235 kg), this ATV will be the heaviest ever lifted by an Ariane rocket.
Replacing the retroreflector won’t be the cosmonauts’ only task. They’ll retrieve an experiment, called Biorisk, that is supposed to evaluate how much microbes affect spacecraft structures. They may also take the Vinoslivost experiment (which looks at how exposed materials behave in space) back inside, depending on how much time they have.
These experiments are part of the long-term mandate of the station’s activities to study how well people and structures survive after years in space. Based on the results, engineers back on Earth can make adjustments for spacecraft under development, making them more robust for long-term missions.
Additionally, the cosmonauts plan to install the Obstanovka experiment, which will look at “space weather” in the Earth’s ionosphere. This region of the atmosphere is where auroras arise after the Sun’s particles strike the area.
Besides producing these pretty patterns, space weather has a darker side: it can cause communications shortouts or hurt satellites. That’s why NASA has the Solar Dynamics Observatory and other spacecraft keeping a close eye on the sun. The agency wants to improve space weather predictions to protect infrastructure on Earth.
You can watch Expedition 35’s first spacewalk on NASA Television at 9:30 a.m. EDT (1:30 p.m. UTC) on Friday. The cosmonauts should head outside around 10:06 a.m. EDT (2:06 p.m. UTC). This could change depending on how quickly the cosmonauts depressurize the Pirs airlock and complete their pre-spacewalk checklist.
This spacewalk will be the seventh for Vinogradov and the first for Romanenko. Including this upcoming spacewalk, there have been 167 spacewalks performed to construct the space station and do maintenance.
Here’s a question… how long does it take sunlight to reach Earth? This sounds like a strange question, but think about it. Sunlight travels at the speed of light. Photons emitted from the surface of the Sun need to travel across the vacuum of space to reach our eyes.
The short answer is that it takes sunlight an average of 8 minutes and 20 seconds to travel from the Sun to the Earth.
If the Sun suddenly disappeared from the Universe (not that this could actually happen, don’t panic), it would take a little more than 8 minutes before you realized it was time to put on a sweater.
Here’s the math. We orbit the Sun at a distance of about 150 million km. Light moves at 300,000 kilometers/second. Divide these and you get 500 seconds, or 8 minutes and 20 seconds.
This is an average number. Remember, the Earth follows an elliptical orbit around the Sun, ranging from 147 million to 152 million km. At its closest point, sunlight only takes 490 seconds to reach Earth. And then at the most distant point, it takes 507 seconds for sunlight to make the journey.
But the story of light gets even more interesting, when you think about the journey light needs to make inside the Sun.
You probably know that photons are created by fusion reactions inside the Sun’s core. They start off as gamma radiation and then are emitted and absorbed countless times in the Sun’s radiative zone, wandering around inside the massive star before they finally reach the surface.
What you probably don’t know, is that these photons striking your eyeballs were ACTUALLY created tens of thousands of years ago and it took that long for them to be emitted by the sun.
Once they escaped the surface, it was only a short 8 minutes for those photons to cross the vast distance from the Sun to the Earth
As you look outward into space, you’re actually looking backwards in time.
The light you see from your computer is nanoseconds old. The light reflected from the surface of the Moon takes only a second to reach Earth. The Sun is more than 8 light-minutes away. And so, if the light from the nearest star (Alpha Centauri) takes more than 4 years to reach us, we’re seeing that star 4 years in the past.
There are galaxies millions of light-years away, which means the light we’re seeing left the surface of those stars millions of years ago. For example, the galaxy M109 is located about 83.5 million light-years away.
If aliens lived in those galaxies, and had strong enough telescopes, they would see the Earth as it looked in the past. They might even see dinosaurs walking on the surface.
NASA is picking up the construction pace on the inaugural space-bound Orion crew capsule at the Kennedy Space Center (KSC) in Florida – and accelerating towards blastoff on the unmanned Exploration Flight Test-1 mission (EFT-1) slated for September 2014 atop a mammoth Delta 4 Heavy Booster which will one day lead to deep space human forays to Asteroids and Mars.
Orion was at the center of an impressive and loud beehive of action packed assembly activities by technicians during my recent exclusive tour of the spacecraft to inspect ongoing progress inside the renovated Orion manufacturing assembly facility in the Operations and Checkout Building (O & C) at KSC.
“We plan to power up Orion for the first time this summer,” said Scott Wilson in an exclusive interview with Universe Today beside the Orion vehicle. Wilson is Orion’s Production Operations manager for NASA at KSC.
The Orion EFT-1 flight is a critical first step towards achieving NASA’s new goal of capturing and retrieving a Near Earth Asteroid for eventual visit by astronauts flying aboard an Orion vehicle by 2021 – if NASA’s budget request is approved.
KSC will have a leading role in NASA’s asteroid retrieval project that could occur some four years earlier than President Obama’s targeted goal of 2025 for a human journey to an asteroid.
Capturing an asteroid and dispatching astronauts aboard Orion to collect precious rock samples will aid our scientific understanding of the formation of the Solar System as well as bolster Planetary Defense strategies – the importance of which is gathering steam following the unforeseen Russian meteor strike in February which injured over 1200 people and damaged over 3000 buildings.
Dozens of highly skilled workers were busily cutting metal, drilling holes, bolting screws and attaching a wide range of mechanical and electrical components and bracketry to the Orion pressure vessel’s primary structure as Universe Today conducted a walk around of the EFT-1 capsule, Service Module and assorted assembly gear inside the O&C.
Lockheed Martin is the primary contractor for Orion. A growing number of employees hired by Lockheed and United Space Alliance (USA) are “working 2 shifts per day 7 days a week to complete the assembly work by year’s end,” said Jules Schneider, Orion Project manager for Lockheed Martin at KSC, during an exclusive interview with Universe Today.
I watched as the workers were boring hundreds of precision holes and carefully tightening the high strength steel bolts to attach the top to bottom ring segments made of titanium to the main load paths on the pressure vessel.
“We are installing lots of wiring to support ground test instrumentation for the strain gauges as well as microphones and accelerometers.”
“The simulated back shell panels are being installed now as guides,” said Wilson. “The real back shell panels and heat shield will be installed onto the structure later this year.”
“The heat shield is the biggest one ever built, 5 meters in diameter. Its bigger than Apollo and Mars Science Lab. It varies in thickness from about 1 to 3 inches depending on the expected heating.”
“We are making good progress on the Orion Service module too. The outer panels will be installed soon,” Wilson explained.
The olive green colored crew module was clamped inside the birdcage-like Structural Assembly Jig during my visit. The Jig has multiple degrees of freedom to maneuver the capsule and more easily enable the detailed assembly work.
“The technicians are installing strain gauges and secondary structure components to get it ready for the upcoming structural loads test,” said Schneider.
“After that we need to finish installing all the remaining parts of the primary structure and a significant portion of the secondary structure.”
For the next stage of processing, the EFT-1 crew module has been lifted out of the birdcage Jig and moved onto an adjacent dedicated work station for loads testing at the Operations and Checkout building.
As reported in my earlier article the Orion pressure vessel sustained three ‘hairline” cracks in the lower half of the aft bulkhead during proof pressure testing of the vessel and welds at the O & C.
I was observing as the technicians were carefully milling out the miniscule bulkhead fractures.
Workers have now installed custom built replacement brackets and reinforcing doublers on the aft bulkhead.
“We will do the protocol loads test with pressure using about 9 different load cases the vehicle will see during the EFT-1 flight. Chute deployment and jettison motor deployment is a driving load case,” said Schneider.
“We will also squeeze the capsule,” said Wilson.
“That structural loads testing of the integrated structure will take about 6 to 8 weeks. There are thousands of gauges on the vehicle to collect data,” Schneider elaborated.
“The test data will be compared to the analytical modeling to see where we are at and how well it matched the predictions – it’s like acceptance testing.”
“After we finish the structural loads tests we can than start the assembly and integration of all the other subsystems.”
“When we are done with the ground testing program then we remove all the ground test instrumentation and start installing all the actual flight systems including harnesses and instrumentation, the plumbing and everything else,” Schneider explained.
Orion hardware built by contractors and subcontractors from virtually every state all across the U.S is being delivered to KSC for installation onto EFT-1. Orion is a nationwide human spaceflight project.
During the unmanned Orion EFT-1 mission, the capsule will fly on a two orbit test flight to an altitude of 3,600 miles above Earth’s surface, farther than any human spacecraft has gone in 40 years.
It will then fire braking rockets to plunge back to Earth, re-enter the atmosphere at about 20,000 MPH and test numerous spacecrafts systems, the heat shield and all three parachutes for an ocean splashdown.
Meanwhile other Orion EFT-1 components such as the emergency Launch Abort System (LAS) and Service Module are coming together – read my Orion follow-up reports.
Humans have not ventured beyond low Earth orbit since the Apollo Moon landings ended in 1972. Orion will change that.
Learn more about Orion, Antares, SpaceX, Curiosity and NASA robotic and human spaceflight missions at Ken’s upcoming lecture presentations:
April 20/21 : “Curiosity and the Search for Life on Mars – (in 3-D)”. Plus “The Space Shuttle Finale and the Future of NASA – Orion, SpaceX, Antares and more!” NEAF Astronomy Forum, Rockland Community College, Suffern, NY. 3-4 PM Sat & Sunday. Display table all day.
April 28: “Curiosity and the Search for Life on Mars – (in 3-D)”. Plus the Space Shuttle, SpaceX, Antares, Orion and more. Washington Crossing State Park, Titusville, NJ, 130 PM
A key mystery in observational lunar astronomy may be at least partially resolved.
An interesting study appeared recently in the British Astronomical Association’s (BAA) March 2013 edition of their Lunar Section Circular. The study is one of the most comprehensive looks at possible connections between Transient Lunar Phenomena and the Solar Cycle.
Transient Lunar Phenomena (or TLPs) are observations collected over the years of flashes or glows on the Moon. Since these phenomena often rely on a report made by a solitary observer, they have been very sparsely studied.
The term itself was coined by Sir Patrick Moore in 1968. One of the very earliest reports of a TLP event was the flash seen on the dark limb of the waxing crescent Moon by Canterbury monks in 1178.
Other reports, such as a daylight “star near of the daytime crescent Moon” seen by the residents of Saint-Denis, France on January 13, 1589 was almost certainly a close conjunction of the planet Venus. Bright planets such as Venus can be easily seen next to the Moon in the daytime.
A stunning illusion also occurs when the Moon occults, or passes in front of a bright star or planet. In fact, there’s a name for this psychological phenomenon of a bright star seeming to “hang” between the horns of the Moon just prior to an occultation, known as the Coleridge Effect. This takes its name from a line in Coleridge’s Rime of the Ancient Mariner;
“Till clomb above the eastern bar, the horned Moon with one bright star,
Within nether tip.”
Okay, we’ve never seen the “horned Moon clomb,” either. But this does describe a real illusion often seen during an occultation. The mind thinks that gap between the horns of the Moon should be transparent, and the lingering planet or star seems to cross that space on the dark limb, if only for a second. Incidentally, South American residents will get to check this out during the next occultation of Venus this year on September 8th.
So, what does this have to do with the 11-year solar cycle? Well, when you strip away many of the dubious observations of TLPs over the years, a core of well- documented events described by seasoned observers remains. Anyone who has sketched such a complex object as the Moon realizes that fine detail becomes apparent on scrutiny that may be missed in a casual glance. But one persistent assertion that has gone around the astronomical community for years is that an increase in the number of TLP events is linked to the peak of the solar cycle.
This was first suggested in 1945 by H. Percy Wilkins. A later study by Barbara Middlehurst in 1966 disproved the idea, citing no statistical correlation between sunspot activity and TLPs.
Of course, pundits have tried unsuccessfully to link the solar cycle to just about everything, from earthquakes to human activity to booms and busts of the stock market. Most flashes on the dark limb of the Moon are suspected to be meteorite impacts. In fact, the advent of high-speed photography has been able to reveal evidence for lunar strikes during intense meteor showers such as the Leonids and Geminids.
What’s at little less clear are the source of luminous “hazes” or “glows” noted by observers. Keep in mind; we’re talking subtle effects noted after meticulous study. NASA even commissioned a study of TLPs named Project Moon-Blink during the early Apollo program. About a third of TLP events have been observed near the bright crater Aristarchus. Researchers even managed to get Neil Armstrong to make an observation of the crater during a pass on Apollo 11. He noted that “there’s an area that is considerably more illuminated than the surrounding area. It seems to have a slight amount of fluorescence.”
But what’s interesting in the recent BAA study conducted by Jill Scambler is the amount of data that was available. The study was a comprehensive analysis of TLPs noted by the BAA, the Association of Lunar and Planetary Observers (ALPO) and NASA from 1700 to 2010. Observations were weighted from 1 to 5, with 1 for reports from inexperienced observers to 5 for definitive and unambiguous TLP events.
The periodogram analysis comparing the frequency of TLPs with the sunspot cycle utilized a tool available from NASA’s Exoplanet Database to evaluate the data. If there was any mechanism whereby TLPs were being generated by solar activity, it had been suggested previously by Wilkins that perhaps out-gassing was being caused be solar irradiation or lunar dust was becoming electrostatically charged and suspended.
In fact, Surveyor 7 witnessed such a phenomenon during lunar twilight. To date, no human has witnessed a sunrise or sunset from the surface of the Moon, although astronauts witnessed several from lunar orbit.
The final conclusion of the BAA study cites that “Although there are theories that might infer that TLP would be more frequent during solar activity, from a sunspot cycle perspective there is no evidence to support this.”
The report provides an interesting perspective on the topic, especially with solar cycle 24 peaking over the next year. It also seems that reports of TLPs have declined in past decades. One of the most famous examples was the flash imaged on the Moon (thought to be a Leonid) by Leon Stuart in 1953. But in the modern era of astrophotography with the Moon under nearly continuous scrutiny, where are all the images of TLPs?
Granted, a core number (2%) of events suggest evidence of real activity on a Moon that we most often think of as geologically dead. As for the spurious sightings, it helps to recall the number of “sightings” in the 19th century of Vulcan transiting the face of the Sun. Where is Vulcan today, with the Sun being monitored around the clock?
We’re not immune to this sort of “echo effect” in the modern world of astronomy, either. For example, whenever an impact scar or flash is noted on Jupiter, as occurred in 2009 and 2012, other sightings are “seen” throughout the solar system. A similar psychological phenomenon occurred when Comet Holmes brightened in 2007. For a time, reports flying around the Internet suggested many comets where suddenly increasing in brightness!
It also interesting to note that many features such as Aristarchus and Ina Caldera also have a high brightness or albedo. Although the Full Moon seems pearly white, the albedo of the Moon is actually quite low at (13%), about that of worn asphalt. Bright ejecta and rays tend to stand out, especially approaching a Full Moon, such as occurs on May 25th.
You can even enhance the saturation of those lunar pics to bring out subtle color and reveal that the Moon isn’t as monochromatic as it appears to the naked eye;
Kudos to the team at the BAA for casting a critical scientific eye on a little studied phenomenon. Perhaps missions such as the Lunar Atmosphere and Dust Environment Explorer (LADEE) departing for the Moon this summer will shed more light on the curious nature of Transient Lunar Phenomena.
-The study can be read in the March 2013 edition of the British Astronomical Association’s Lunar Section Circular available as a free pdf.
The Week in Space Pictures was something new we launched last week and we’re trying to improve on it with this eye-catching info graphic. Let us know what you think!
NASA’s Near-Earth Object Office says that new observations of comet C/2013 A1 (Siding Spring) have allowed further refinements of the comet’s orbit, helping to determine the chances it could hit Mars in October of 2014. Shortly after its discovery in December 2012, astronomers thought there was an outside chance that a newly discovered comet might be on a collision course with Mars.
While the latest orbital plot places the comet’s closest approach to Mars slightly closer than previous estimates, the new data now significantly reduces the probability the comet will impact the Red Planet, JPL said, from about 1 in 8,000 to about 1 in 120,000.
The closest approach is now estimated at about 68,000 miles (110,000 kilometers). The most previous estimates had it whizzing by at 186,000 miles (300,000 kilometers).
The latest estimated time for close approach to Mars is about 11:51 a.m. PDT (18:51 UTC) on Oct. 19, 2014. At the time of closest approach, the comet will be on the sunward side of the planet.
The comet was discovered in the beginning of 2013 by comet-hunter Robert McNaught at the Siding Spring Observatory in New South Wales, Australia. When the discovery was initially made, astronomers at the Catalina Sky Survey in Arizona looked back over their observations to find “prerecovery” images of the comet dating back to Dec. 8, 2012. These observations placed the orbital trajectory of comet C/2013 A1 right through Mars orbit on Oct. 19, 2014.
JPL says future observations of the comet are expected to refine the orbit further. The most up-to-date close-approach data can be found at JPL’s Small Body Database.
An interesting news item from Iran’s Entkhab news agency: Iranian scientist Ali Razeghi – who is also the managing director of Iran’s Center for Strategic Inventions — has registered a new invention of his own making: a time machine.
It’s doesn’t actually take anyone to the past or future, but produces printed reports with details about the future, and can “predict five to eight years of the future life of any individual, with 98 percent accuracy” according to Razeghi, as quoted in The Telegraph.
“My invention easily fits into the size of a personal computer case and can predict details of the next 5-8 years of the life of its users,” he says. It will not take you into the future, it will bring the future to you.”
Razeghi, 27, says he has been working the project for 10 years and this is the 179th invention he has registered.
The “time machine” would be a good resource for governments, he said, but he doesn’t want to launch a prototype at this point because “the Chinese will steal the idea and produce it in millions overnight.”
Razeghi said his latest project has been criticized by friends for “trying to play God” with ordinary lives and history. “This project is not against our religious values at all,” Razaghi was quoted. “The Americans are trying to make this invention by spending millions of dollars on it where I have already achieved it by a fraction of the cost.”