Ethiopia has launched the initial phase of its space exploration program which includes East Africa’s largest observatory.
The $3.4 million observatory located 3200m above sea level in the outskirts of Addis Ababa is expected to begin operating in a few days. It will be run by the Ethiopian Space Science Society (ESSS) with funding from Ethiopian-Saudi business tycoon, Mohammed Alamoudi.
Two telescopes, each 1m wide, will be used to observe “extra planets, different types of stars, the Milky Way, and deep galaxies,” said the observatory’s director, Solomon Belay. “The optical astronomical telescope is mainly intended for astronomy and astrophysics observation research.”
The observatory will be used for collecting data, conducting research and building local and regional interest in astronomy, but the possibility of sending an Ethiopian to space one day cannot be ruled out.
Several sceptics have questioned the necessity of the program, considering the fact that Ethiopia is among the poorest countries in Africa and the world.
Belay however told AFP that promoting science and technology was important to Ethiopia’s development.
“If the economy is strongly linked with science, then we can transform a poor way of agriculture into industrialization and into modern agriculture,” he said.
He added that the country also stands to benefit from “astronomy tourism” since the observatory is expected to attract some fans from Africa and the world.
Ethiopia will launch its first satellite in about 3 years. The satellite is expected to be used to study meteorology and improve telecommunication in the east African nation. In preparation for this, the ESSS also plans to construct another observatory in Lalibella very soon. Already experts are reported to be exploring the site for the best area to set up the observatory.
Many African nation shave shown interest in getting close to the stars. In 2009, the African Union announced plans to set up an African Space Agency. Currently, about 8 African nations have already set up space-related programs and others, including Ghana, are expected to join the ranks in the next few years.
Quelle: Zegabi - East Africa News
A research team led by Tomoro Sashida and Tomoharu Oka (Keio University) has succeeded in precisely measuring the expansion velocity of a shockwave of the supernova remnant W44. The remnant is located in the constellation of Aquila, approximately 10,000 light-years away from our solar system. The team observed the high-temperature and high-density molecular gas in the millimeter/submillimeter wave ranges. The analysis shows that the expansion velocity of the W44 shockwave is 12.9±0.2 km/sec. In addition, it became clear that the supernova explosion released kinetic energy of (1-3)×1050 erg into the interstellar medium. The energy emitted from the Sun is approximately 3.6 × 1033 ergs/sec. Can you image how enormous amount of energy is released from the supernova explosion? Furthermore, other molecular gas with an extremely high velocity of higher than 100 km/sec was also detected. The origin of this super-high-velocity molecular gas remains unclear at the present time.
A star with a mass of more than eight times of the Sun releases tremendous energy when it is dying and undergoes a supernova explosion. The shockwave caused by the supernova explosion expands, having a strong impact on the composition and physical state of surrounding interstellar materials. It also emits kinetic energy into interstellar space. “Galactic winds” blasting out a large amount of gas are often observed in galaxies where explosively active star formations take place. The energy source of such galactic wind is also thought to be many supernova explosions.
Thus, supernova explosions have an immense influence on interstellar space. Nevertheless, there has been no quantitative research on the expansion velocity and kinetic energy of a supernova shockwave. This is because wide area must be observed in order to study the expansion velocity and kinetic energy of a supernova shockwave. Wide area observations with the existing equipment require quite long observation times. Therefore, observations of interstellar gas influenced by a supernova shockwave have been limited to a narrow area.
The research team started its observations mainly with radio telescopes in late 1990s. The purpose is to study interaction of the supernova remnant W44 and the adjacent giant molecular cloud (GMC). W44 is a roughly 6,500~25,000-year-old supernova remnant located approximately 10,000 light-years away from the solar system. Attached to the remnant is a GMC with a mass of approximately 300,000 times the mass of the Sun. Since observation began, molecular spectrum lines with a wide velocity width have been detected in the W44 molecular cloud in various places. They have been interpreted to be gas that has been accelerated by the passage of the supernova shockwave.
The research team used the 45m Telescope at Nobeyama Radio Observatory (NRO), National Astronomical Observatory of Japan (NAOJ), and the 10m ASTE (Atacama Submillimeter Telescope Experiment) telescope to make high-sensitivity video imaging observations of the full area of W44.
The observations revealed that spectrum lines with a wide velocity width were detected throughout the whole area where W44 overlapped the GMC. The research team calculated velocity centroids from these spectrum lines and examined their spatial distribution. From the distribution, a clear velocity gradient was found throughout from the center to the edge of W44. This can be thought as the expansion activity of shocked gas, or molecular gas affected by a shockwave. Based upon the uniform expansion model of the rotating spheroid, expansion velocity of 12.9±0.2 km/sec was estimated. The mass of shocked gas was evaluated as 1.2±0.6 times the mass of the Sun based on the spectral intensity. From these values, we were able to estimate the whole kinetic energy transmitted from the supernova remnant to interstellar materials as (1-3)×1050 erg. This value is equal to 10~30% of the total energy of the supernova explosion (~1051 erg), and roughly consistent with previous theoretical predictions (about 10%).
In addition, the observations detected a molecular gas component with an extremely high velocity (>100 km/sec). These positions of super-high-velocity molecular gas are the exact locations where the sources of continuum radiation and a molecular hydrogen oscillation emission line are also detected. This indicates that very strong shockwaves existed locally. The origin of the super-high-velocity component remains a mystery at the present time.
The research team plans to plow ahead this research to uncover the nature of the mysterious component. Furthermore, the team will observe a larger number of shocked gases surrounding the supernovae to confront these observational results with theoretical models of a supernova shockwave.
Figure 1) Radio wave image of the direction to the supernova remnant W44. (a) Line intensity map of HCO+ J=1-0 rotational transition, (b) Line intensity map of CO J=3-2 rotational transition, (c) Line intensity map of CO J=1-0 rotational transition, (d) Intensity map of 1.4 GHz radio continuum radiation. The red cross shows the position that the “super-high-velocity component” is detected.
Figure 2) The relations between the distance from the center of supernova remnant and the radial velocity calculated from Doppler shift of spectrum line. (a) is the HCO+ J=1-0 spectrum line, (b) is the CO J=3-2 spectrum line, the red line represents the result of model fit.
Figure 3) (a) The spatial structure, (b) position-velocity diagram, and (c) CO J=3-2 emission line spectrum of the central direction of the “super-high-velocity component”
Figure 4) Image illustration of propagation W44 shockwaves in the molecular cloud.
Quelle: National Astronomical Observatory of Japan.
A research team, led by reseacher at the National Astronomical Observatory of Japan (NAOJ), discovered that the more massive black holes tend to be located in galactic environments with higher density . This finding indicates that galaxies in a dense area often merge together, causing the growth of massive black holes.
An artist’s illustration of galaxy distribution, a host galaxy of an active galactic nucleus (AGN), and an active galactic nucleus. An AGN is a luminous compact region at the center of the galaxy, powered by the accretion of gas onto the massive black hole. This research reveals that the mass of a massive black hole at the galaxy center is related to the distribution of surrounding galaxies.
The research team investigated environment in which a galaxy with a massive black hole at its center exists. The team’s research extended over data for approximately 70 million galaxies, with approximately 10,000 massive black holes researched. This vast amount of data was collected through the Virtual Observatory; it connects a variety of astronomical databases around the world via the Internet, making it possible to comprehensively use the collected data.
The difference of galactic density according to black-hole mass (the vertical axis shows the size of regions with enhanced galactic density: the bigger the size, the higher the density). The heavier black holes are located in galaxies with higher density for black holes with mass larger than ~10^8 solar mass. While the less massive black holes show no correlation between the mass of black holes and the density of galaxies.
Quelle: National Astronomical Observatory of Japan
CAPE CANAVERAL AIR FORCE STATION, Fla., Sept. 17, 2013 – Boeing [NYSE: BA] workers lift the Global Positioning System (GPS) IIF-5 satellite onto a transporter following its Aug. 1 arrival at the Navstar Processing Facility on Cape Canaveral Air Force Station, Fla.
With a launch-heavy weekend behind us—Sunday, 29 September having seen both the successful maiden flight of SpaceX’s new Falcon 9 v1.1 from Vandenberg Air Force Base, Calif., and the return to flight of the troubled Proton-M booster from Baikonur, Kazakhstan—it will be a little longer before we next hear the roar of space-bound rocket engines. United Launch Alliance (ULA) tweeted yesterday that its next flight has slipped from 17 to 23 October. In response to a request for information on their Twitter page, the company announced that the delay is “to allow technicians time to change out a faulty ground system valve on the liquid oxygen storage tank prior to launch.” The mission will see a Delta IV carry the Global Positioning System (GPS) IIF-5 satellite into a medium orbit, more than 11,000 miles above Earth.
The Delta IV will fly in its Medium+ 4,2 configuration, numerically designated to identify its 4-meter (13-foot) payload fairing and the presence of two solid-fueled Graphite Epoxy Motors (GEM)-60. The central component of the vehicle is a single Common Booster Core (CBC), which stands 134 feet tall and is powered by a single Rocketdyne-built RS-68 liquid oxygen and hydrogen engine. This will ignite at T-5 seconds and undergo several seconds of computer-controlled health checks, ahead of the ignition of the GEM-60s at T-0.01 seconds and a release of hold-down clamps and liftoff at T-0. The Medium+ 4,2 configuration of the Delta IV has the capacity to inject up to 12,890 pounds of payload into geostationary transfer orbit.
The upcoming launch will also represent the 25th Delta IV mission since the vehicle’s maiden voyage in November 2002. It has chalked up an impressive track record, with all but one of its missions classed as full successes. Only the first flight of the Delta IV Heavy in December 2004 experienced a premature shutdown of its CBCs, which caused one of its satellite cargoes to enter an incorrect orbit and the other to fail to achieve orbit entirely. Last October, a Delta IV Medium+ 4,2 experienced a problematic ascent when its RL-10B2 upper stage engine suffered a period of reduced thrust. Fortunately, the Delta’s robust system design, flight software, vehicle margins, and propellant reserves compensated for the shortfall, and the GPS IIF-3 primary payload was inserted safely into orbit.
However, the incident led to an investigation into the cause of the glitch. Experts from ULA and the Air Force implemented a number of corrective actions. These included thorough inspections of engine and Delta IV systems for damage or the presence of “foreign objects,” coupled with in-flight helium purges to critical components and changes to how the restartable RL-10B2 was thermally conditioned during ascent, ahead of its first “burn.” The commonality of the RL-10B2 on the Delta IV and the RL-10A on the Atlas V—also operated by ULA—meant both vehicles were grounded, pending a resolution of the problem. As the Delta IV work continued, an Atlas V successfully delivered the Air Force’s X-37B spacecraft into orbit without incident in December 2012.
Finally, with a clean bill of health, the Delta IV returned to flight in late May 2013, delivering the U.S. Air Force’s fifth Wideband Global Satcom (WGS-5) into orbit, followed by the sixth in early August. Both missions flew in the Medium+ 5,4 configuration, with a larger 5-meter (16-foot) payload fairing, a modified second stage with 5-meter liquid hydrogen tank and “stretched” liquid oxygen tank, and four GEM-60 boosters. Three weeks later, on 28 August, the Delta IV Heavy—which utilizes three CBCs and is presently the largest rocket in operational service, anywhere in the world—successfully lofted the National Reconnaissance Office’s NROL-65 classified payload into orbit.
According to schedules posted by Spaceflight Now, liftoff of the GPS IIF-5 mission from Space Launch Complex (SLC)-37 at Cape Canaveral Air Force Station, Fla., is scheduled for 5:53 p.m. EDT on 23 October, at the start of a planned 19-minute “window” for that day. At T-5 seconds, its single RS-68 first-stage engine will roar to life, followed at T-0.01 seconds by the ignition of the two side-mounted GEM-60 boosters. At T-0, the 206-foot-tall Delta will be released from the pad surface and commence a fast climb away from SLC-37. About eight seconds after liftoff, the vehicle will execute an automated pitch, yaw, and roll program maneuver to establish itself on the proper flight azimuth for delivery of GPS IIF-5 into orbit. Powered by its RS-68 engine and twin boosters, it will burst through the sound barrier at about T+47 seconds. At one minute into the flight, it will encounter a period of maximum aerodynamic turbulence on the airframe, known colloquially as “Max Q.”
Following the separation of the GEM-60s, about 105 seconds into the flight, the RS-68 will continue the push toward orbit for a further three minutes. It will shut down and be discarded about four minutes after launch, after which the Delta Cryogenic Second Stage (DCSS)—powered by the Pratt & Whitney RL-10B2 engine which caused such troubles during its last Delta IV Medium+ 4,2 outing in October 2012—will roar to life and take over. Twelve minutes after leaving SLC-37, the DCSS will achieve an initial “parking orbit” and will shut down, then coast for several minutes, before reorienting itself for a second burn. After the completion of the three-minute-long second burn, the DCSS and the GPS IIF-5 payload will coast for three hours, preparatory to a third burn. This final burn will last about two minutes and will position GPS IIF-5 correctly for separation from its Payload Attach Fitting (PAF) at about 3.5 hours into the flight.
Weighing 3,600 pounds, GPS IIF-5 is the latest in an “interim” class of Global Positioning System satellites to keep a critical worldwide positioning, velocity, and timing asset operational until the next-generation GPS Block IIIA comes online sometime in 2014. The spacecraft boasts improved-accuracy positioning systems, a reprogrammable processor, capable of future upgrades, an interference-free civilian signal for commercial aviation search-and-rescue, and better resistance to electronic jamming through the new “M-code” military GPS signal. The first member of the planned 12-strong constellation of Block IIF satellites was launched in May 2010. It was followed by GPS IIF-2 in July 2011, GPS IIF-3 in October 2012, and GPS IIF-4—aboard an Atlas V—in May 2013.
“As each IIF satellite becomes operational, we continue the seamless transformation of the GPS constellation into an even more accurate, reliable, and durable navigation resource for the U.S. military and the global civilian user community,” said Craig Cooning, vice president and general manager of GPS Block IIF prime contractor Boeing Space & Intelligence Systems. “Our efficient pulse-line manufacturing process, adapted from Boeing’s commercial airplane production lines, also ensures that we deliver each spacecraft on time and on cost.”
In the meantime, the U.S. Air Force awarded Lockheed Martin a $1.4 billion contract in May 2008 to develop the Block IIIA network, which may eventually consist of as many as 32 satellites. At present, the Air Force has formally contracted for four Block IIIAs. With 500 times the transmitter power of current systems, Block IIIA will also benefit from new navigational warfare capabilities, enabling them to shut off GPS service to limited geographical locations whilst maintaining service to U.S. and allied forces. The GPS system is operated and controlled by the 50th Space Wing, located at Schriever Air Force Base, Colo.
United Launch Alliance’s scheduled Oct. 23 launch of a U.S. Air Force satellite is being postponed as the rocketmaker continues to investigate the cause of a fuel leak during the launch of the same kind of rocket a year ago.
The Centennial-based company announced the reasons for delay Friday. It’s the second rescheduling of the Boeing Co.-built GPS IIF-5 satellite lift off on a Delta IV rocket.
ULA has been continuing to investigate anomolies from the successful Oct. 4, 2012 launch of a GPS satellite aboard a Delta IV. Pratt & Whitney Rocketdyne of Canoga Park, Calif., makes the RL-10B-2 engine used in the Delta IV rocket’s upper stage. That engine didn’t produce the expected thrust during last year’s launch.
“It was determined that a fuel leak occurred within the engine system and that this fuel leak caused the low thrust,” the ULA statement said.
An earlier phase of the investigation into the anomaly delayed a launch last November of an experimental, unmanned Air Force space plane. ULA recently updated conclusions from last year’s flight data and is delaying this month’s GPS IIF launch while it determines whether the new conclusions suggest changes to the engine should be made.
The upcoming Nov. 18 launch scheduled for the Mars Atmosphere and Volatile Evolution mission (MAVEN) is unaffected by the investigation, ULA said. That launch is aboard one of ULA's Atlas V rockets.
The center of the Milky Way galaxy imaged by NASA's Spitzer Space Telescope.
For NASA and its dozens of missions, data pour in every day like rushing rivers. Spacecraft monitor everything from our home planet to faraway galaxies, beaming back images and information to Earth. All those digital records need to be stored, indexed and processed so that spacecraft engineers, scientists and people across the globe can use the data to understand Earth and the universe beyond.
At NASA's Jet Propulsion Laboratory in Pasadena, Calif., mission planners and software engineers are coming up with new strategies for managing the ever-increasing flow of such large and complex data streams, referred to in the information technology community as "big data."
How big is big data? For NASA missions, hundreds of terabytes are gathered every hour. Just one terabyte is equivalent to the information printed on 50,000 trees worth of paper.
"Scientists use big data for everything from predicting weather on Earth to monitoring ice caps on Mars to searching for distant galaxies," said Eric De Jong of JPL, principal investigator for NASA’s Solar System Visualization project, which converts NASA mission science into visualization products that researchers can use. "We are the keepers of the data, and the users are the astronomers and scientists who need images, mosaics, maps and movies to find patterns and verify theories."
Building Castles of Data
De Jong explains that there are three aspects to wrangling data from space missions: storage, processing and access. The first task, to store or archive the data, is naturally more challenging for larger volumes of data. The Square Kilometer Array (SKA), a planned array of thousands of telescopes in South Africa and Australia, illustrates this problem. Led by the SKA Organization based in England and scheduled to begin construction in 2016, the array will scan the skies for radio waves coming from the earliest galaxies known.
JPL is involved with archiving the array's torrents of images: 700 terabytes of data are expected to rush in every day. That's equivalent to all the data flowing on the Internet every two days. Rather than build more hardware, engineers are busy developing creative software tools to better store the information, such as "cloud computing" techniques and automated programs for extracting data.
"We don't need to reinvent the wheel," said Chris Mattmann, a principal investigator for JPL's big-data initiative. "We can modify open-source computer codes to create faster, cheaper solutions." Software that is shared and free for all to build upon is called open source or open code. JPL has been increasingly bringing open-source software into its fold, creating improved data processing tools for space missions. The JPL tools then go back out into the world for others to use for different applications.
"It's a win-win solution for everybody," said Mattmann.
In Living Color
Archiving isn't the only challenge in working with big data. De Jong and his team develop new ways to visualize the information. Each image from one of the cameras on NASA's Mars Reconnaissance Orbiter, for example, contains 120 megapixels. His team creates movies from data sets like these, in addition to computer graphics and animations that enable scientists and the public to get up close with the Red Planet.
"Data are not just getting bigger but more complex," said De Jong. "We are constantly working on ways to automate the process of creating visualization products, so that scientists and engineers can easily use the data."
Data Served Up to Go
Another big job in the field of big data is making it easy for users to grab what they need from the data archives.
"If you have a giant bookcase of books, you still have to know how to find the book you're looking for," said Steve Groom, manager of NASA's Infrared Processing and Analysis Center at the California Institute of Technology, Pasadena. The center archives data for public use from a number of NASA astronomy missions, including the Spitzer Space Telescope, the Wide-field Infrared Survey Explorer (WISE) and the U.S. portion of the European Space Agency's Planck mission.
Sometimes users want to access all the data at once to look for global patterns, a benefit of big data archives. "Astronomers can also browse all the 'books' in our library simultaneously, something that can't be done on their own computers," said Groom.
"No human can sort through that much data," said Andrea Donnellan of JPL, who is charged with a similarly mountainous task for the NASA-funded QuakeSim project, which brings together massive data sets -- space- and Earth-based -- to study earthquake processes.
QuakeSim's images and plots allow researchers to understand how earthquakes occur and develop long-term preventative strategies. The data sets include GPS data for hundreds of locations in California, where thousands of measurements are taken, resulting in millions of data points. Donnellan and her team develop software tools to help users sift through the flood of data.
Ultimately, the tide of big data will continue to swell, and NASA will develop new strategies to manage the flow. As new tools evolve, so will our ability to make sense of our universe and the world.
A big asteroid sailed past Earth last month, and astronomers haven't yet totally excluded the possibility that it'll hit us when it comes around in 2032. If the past is any guide, we won't have to worry about asteroid 2013 TV135 — but it's a reminder that we'll have to fend off a killer space rock one of these days.
Ukrainian astronomers discovered 2013 TV135 just 10 days ago, well after the asteroid had its close encounter with Earth on Sept. 16. Actually, it wasn't all that close: The distance was 4.2 million miles (6.7 million kilometers), or about 17 times as far away as the moon. But based on the rough estimates of its orbital path, experts rated its chances of colliding with Earth during a follow-up encounter in 2032 at 1 in 63,000.
"To put it another way, that puts the current probability of no impact in 2032 at about 99.998 percent," Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory, said Thursday in a statement. "This is a relatively new discovery. With more observations, I fully expect we will be able to significantly reduce, or rule out entirely, any impact probability for the foreseeable future."
Russia sounds alarm
Earth has faced tougher odds: At one point, astronomers gave the asteroid Apophis a 1-in-40 chance of hitting Earth in 2029. Further observations ruled out any chance of impact in the foreseeable future, and the case of 2013 TV135 will almost certainly play out the same way.
That didn't stop Russian Deputy Prime Minister Dmitry Rogozin, who has space research as part of his portfolio, from tweeting an alarm. "'A 400-meter asteroid threatens to blow up the Earth,'" he wrote in Russian. "Well, that's a super goal for domestic space."
Just last month, Energy Secretary Ernst Moniz signed an agreement with Russian officials that the Energy Department said would include seeing whether nuclear weapons could be used as a means of asteroid defense.
Nukes or not, asteroid defense is an international issue well worth contemplating: A space rock that's 1,300 feet (400 meters) wide could destroy a region or set off a huge tsunami if there were a direct hit. The asteroid that caused a meteor blast over Russia earlier this year, injuring more than 1,600 people, was a mere 17 meters (54 feet) wide when it hit Earth's atmosphere.
The United Nations is in the midst of figuring out the procedure for international action in the event of an asteroid catastrophe — and NASA's OSIRIS-REx mission, due for launch to asteroid Bennu in 2016, may help astronomers develop strategies for diverting a potentially threatening space rock. But for now, the big challenge is to identify and characterize near-Earth objects on a timely basis. The fact that 2013 TV135 was discovered only after last month's close encounter demonstrates how far we have yet to go.
Nukes or not, asteroid defense is an international issue well worth contemplating: A space rock that's 1,300 feet (400 meters) wide could destroy a region or set off a huge tsunami if there were a direct hit. The asteroid that caused a meteor blast over Russia earlier this year, injuring more than 1,600 people, was a mere 17 meters (54 feet) wide when it hit Earth's atmosphere.
A potentially catastrophic asteroid has been discovered by astronomers, who say there’s a slim chance that the 410-meter-wide minor planet will crash into Earth in 2032, creating a blast 50 times greater than the biggest nuclear bomb.
The asteroid, described as 2013 TV135, was found in the Camelopardalis (Giraffe) constellation by the Crimean Astrophysical Observatory in southern Ukraine, the Minor Planet Center of the International Astronomers Union said.
“On the night of October 12, I was watching the Giraffe constellation, it was an in-depth monitoring as part of the comet search program,” Gennady Borisov from the Crimean Astrophysical Observatory told Itar-Tass news agency. “This is when the asteroid… was discovered. The first observations show that it moves quickly and is relatively close.”
The discovery has been confirmed by astronomers in Italy, Spain, the UK and Russia. In Russia, it was seen with telescopes at the Master Observatory in the Siberian republic of Buryatia, the IAU Minor Planet Center said.
The asteroid has been added to the List of the Potentially Hazardous Asteroids, which includes celestial bodies with orbits closer than 7.5 million kilometers from the Earth’s orbit.
However, the threat posed by 2013 TV135 is minor, as it only has a one in 63,000 chance of colliding with our planet, according to available estimates.
Astronomers say the asteroid’s orbit will be about 1.7 million kilometers away from the Earth’s orbit on August 26, 2032.
If the asteroid hits Earth, it would create an explosion equivalent to 2,500 megatons of TNT, which is 50 times greater than the biggest nuclear bomb ever detonated.
Scientists will be able to better evaluate the impact risk of 2013 TV135, and even determine its possible impact site on Earth by 2028, Timur Kryachko from the Crimean Astrophysical Observatory told the RIA Novosti news agency.
The discovery was mentioned by Russian Deputy Prime Minister Dmitry Rogozin, who is pushing for the development of anti-asteroid defense systems.
“Here’s a super-task for our space industry,” Rogozin said of the asteroid on his Twitter page.
The 2013 TV135 has been given a 1 out of 10 rating on the Torino Scale, used to estimate asteroid impact hazards, which means it “poses no unusual level of danger” and “the chance of collision is extremely unlikely.”
According to NASA’s Near Earth Object Program, there is currently just one asteroid that has the same rating. It’s called 2007 VK184. At 130 meters wide, it has 1 in 1,820 chance of impacting Earth on June 3, 2048.
The chances that any other near-Earth asteroid will crash into earth in the next 100 years is estimated at “effectively zero” by NASA.
Ring of fire: HST image of the most distant gravitational lens
The most distant gravitational lens yet has been found at a colossal distance of 9.4 billion light-years. The chance discovery by an international team of astronomers not only allowed the team to directly measure the mass of the distant galaxy that caused the lensing but has also led to questions about the more distant object whose light was lensed. The magnified object is a type of dwarf galaxy that is thought to be rare and the chances that such a peculiar galaxy would be gravitationally lensed are small. Therefore its observation suggests that current theories have underestimated the number of such galaxies in the early universe.
A gravitational lens is a large galaxy or group of galaxies that bends or "lenses" light from a distant source as it travels towards an observer. The effect was predicted by Einstein's general theory of relativity. In rare cases the lens, the distant light source and the observer line up precisely and the result is an "Einstein ring" – a perfect circle of light around the lensing mass. However, if there is any misalignment along the way, astronomers observe partial arcs, spots and other such distorted images, depending on the relative positions of the bodies.
Such a lensing effect has proved to be useful – researchers can determine the mass of the lensing galaxy including its dark matter content – thanks to the amount of distortion or lensing observed. The lensing effect also acts as a "natural telescope" of sorts, magnifying details of distant galaxies that would be difficult to observe otherwise. Indeed, ever since the first evidence of such lensing was seen in 1979, astronomers and cosmologists have used the phenomenon to find distant objects and supernovae and to even map the dark-matter content of our universe.
Now, a team led by Arjen van der Wel from the Max Planck Institute for Astronomy in Heidelberg, Germany, along with colleagues in Italy and the US, has, rather accidently, detected the furthest such lens. Van der Wel was reviewing observations made with the Large Binocular Telescope in Arizona that were part of another study that looked at the spectra of massive, old galaxies."[I] noticed a galaxy that was decidedly odd. It looked like an extremely young galaxy, and at an even larger distance than I was aiming for," says Van der Wel. Intrigued by the anomalous object, he looked at other images of the object taken with the Hubble Space Telescope as part of the CANDELS and COSMOS surveys and once more the object looked like an old galaxy but with some irregular features. As a result, Van der Wel suspected that he might be looking at a gravitational lens. He combined all the available images of the object and corrected for the haze of the lensing galaxy's stars to see a "quadruple lens" that formed an almost perfect Einstein ring.
The researchers found that after being deflected, light from the lens travelled nearly 9.4 billion years to reach us, corresponding to a redshift of z = 1.53. This puts the lens much further away than other lenses discovered to date. From the amount of distortion observed, the researchers calculated that the lens galaxy has a total mass of 8 × 1010 solar mass. From that, nearly 75% of this is made up of stars, meaning that the rest of the mass could consist of dark matter. But Van der Wel explains that uncertainties are such that all mass in the lens can be accounted for by stars only.
Seeing an Einstein ring also means that both the lens and the background light source are aligned to better than 0.01 arcseconds – that is equivalent to a 1 mm separation at a distance of 20 km. Van der Wel tells physicsworld.com that this was indeed a rare alignment – "If the light rays are darts thrown in New York City, then they managed to hit the bullseye of a dartboard in Boston. Now, the universe throws many darts around (there are many background galaxies) and has many dartboards (many potential foreground lenses), but not that many. The chances of hitting a dartboard are not so small, but the chances of hitting the bullseye..." exclaims Van der Wel.
But the distance and fortuitous alignment were not the only surprises from this study. The background light-source galaxy (even more distant at z = 3.41) itself proved to be a "star-bursting dwarf galaxy". This is a comparatively low-mass galaxy (only about 100 million solar mass worth of stars) that is extremely young (only about 10–40 million years old) and produces new stars at an enormous rate. Such dwarf starburst galaxies are thought to be rare and the chance of these peculiar galaxies being lensed is small. Yet this is the second starbursting dwarf galaxy found to be lensed. This might force astronomers to re-think their models of galaxy evolution as starbursting dwarf galaxies might be much more common than previously thought. "Perhaps only one in a hundred faint galaxies is a starbursting dwarf galaxy. That combined with the chance alignment makes this a very unlikely object," says Van der Wel.
The research is to be published in Astrophysical Journal Letters. A preprint is available on arXiv.
This picture from the NASA/ESA Hubble Space Telescope shows the most distant gravitational lens yet discovered. The light from the more distant object is bent around the nearer object by its strong gravitational pull to form a ring of multiple images. The chance of finding such an exact alignment is small, suggesting that there may be more star-forming galaxies in the early universe than expected. (Courtesy: NASA/ESA/A van der Wel)
Quelle: Physics World
Observations from NASA's Kepler spacecraft have uncovered a 'tilted' solar system, a finding that gives clues as to how some planets come to orbit their stars on paths that are misaligned with the stars' equators, astronomers report today in Science.
The planets of Earth's Solar System formed from a flat disc of gas and dust revolving around the Sun's equator, so they all started out in nearly the same plane. Earth’s orbit makes an angle of just 7.2 degrees with the plane of the Sun’s equator.
Five years ago, however, astronomers were shocked to find planets orbiting at steep angles to their stars’ equators. Some planets even went around their suns backwards — they orbit in the opposite direction to the star’s rotation . But no one had seen a misaligned multiplanetary solar system until now.
For the latest study, astronomer Daniel Huber of NASA’s Ames Research Center in Moffett Field, California, and his colleagues looked at Kepler-56, a star roughly 860 parsecs (2,800 light years) from Earth. It has two large planets that lie in the same planeand circle closer to their sun than Mercury does to ours. Kepler detected the planets as they blocked the star's light, so their orbits are oriented edge-on to our line of sight.
Kepler-56 is a giant star that's four times larger than the Sun and emits nine times more light. To determine the star’s orientation, researchers used Kepler to study variations in its brightness, which arise from the star's vibrations and look different depending on whether the star is viewed equator-on, pole-on or somewhere in between.
The observations revealed that the plane of the star's equator tilts 45 degrees to the planets’ orbits. “It was a big surprise,” Huber says.
To find out what caused the tilting, the astronomers measured the velocity of Kepler-56 through space using the 10-metre Keck I telescope on Mauna Kea in Hawaii. “That revealed the culprit,” Huber says: a distant body whose gravitational pull tugs the star and also tilts the planets’ orbits. Despite the enormous tilt, the planets' orbits stay aligned with each other because they're in resonance: one planet takes twice as long as the other to circle the star, so they periodically nudge each other through their gravity. Their orbits therefore remain co-planar even as they deviate radically from the star's equator.
“It’s a fascinating discovery,” says Amaury Triaud, an astronomer at the Massachusetts Institute of Technology in Cambridge. “It’s nature: you observe, and you find extraordinary stuff.”
...werden Web-Seiten wie der NASA eingestellt und man bekommt statt neuester Informationen diesen Text zu lesen:
Due to the lapse in federal government funding, this website is not available.
We sincerely regret this inconvenience.
For information about available government services, visit USA.gov.
Este sitio web no se está disponible durante el cierre del Gobierno.
Lamentamos profundamente las molestias que esto pueda causar.
Visite GobiernoUSA.gov para informarse sobre los servicios gubernamentales disponibles durante el cierre del Gobierno.
Wann kommt die US-POLITIK zur Besinnung, daß das Wohl Vieler mehr wiegt als die Macht Weniger. Möge das Volk die richtige Antwort geben bei der nächsten Wahl!
(CNN) -- The world-famous Hubble Space Telescope is owned by the U.S. government and operated cooperatively by NASA and an institute under contract to NASA. Now that the government has shut down, the institute can still use existing resources to continue Hubble operations for as long as possible. Its staff has tried to ensure that -- to the extent possible -- the shutdown will not affect telescope operations.
But events can overtake plans. If Hubble encounters a problem or a glitch, as happens occasionally, science operations will be suspended and the spacecraft will be locked into safe mode until government employees can issue spacecraft commands to restore operations.
Safe mode means orienting the delicate instruments away from the sun while keeping the solar panels illuminated, to make sure no instrument loses power and is ruined. But in safe mode, the instruments won't record any of the light coming to the telescope.
The approximate cost of one hour of Hubble observing is somewhere between $8,000 and $25,000, depending on whether one adds the costs of operating and refurbishing the facility to its initial construction costs. That means a two-week government shutdown could waste $3 million, $5 million, even $8 million of taxpayer investment.
Frankly, the loss to science is far greater. Each year thousands of astronomers from around the world compete to decide where Hubble will point -- toward particular stars or planets or galaxies or gravitational lenses. Special science panels spend weeks setting priorities for the most important proposed science investigations. For every 10 hours of observing time astronomers want to use, only 1 hour is eventually approved.
U.S. shutdown threatens launch of NASA's next mission to Mars
That means each week the government is shut down could cost dozens to hundreds of critical astronomical observations.
The James Webb Space Telescope, Hubble's successor, is undergoing critical tests at the Goddard Space Flight Center. This has to be done at extremely cold temperatures, mimicking conditions in space, and the amount of time to cool the system down is one of the drivers of schedule and therefore cost.
As long as the government remains shut down, the testing will have to wait. If the shutdown lasts more than a few weeks, the JWST instrument module will have to be warmed up, probably pushing the launch date forward by a few months and raising the cost commensurately (about $1 million per day).
NASA operates dozens of scientific spacecraft. A few look out at the cosmos, like Hubble. Many monitor the sun and the particle environment around Earth. Such observations have provided early warning of major sunstorms (known by solar scientists as "coronal mass ejections") that can knock out communications satellites and other fragile electronics.
To check on the number of satellites that might be affected by the shutdown, this author tried to access a NASA website, only to see the following message: "Due to the lapse in federal government funding, this website is not available. We sincerely regret the inconvenience."
This prompted further searching. The main NASA website defaults to the same error message. The education and outreach pages maintained by astronomers at the Goddard Space Flight Center -- and read by schoolchildren across the country -- are not accessible.
The Jet Propulsion Laboratory, because it is run under contract to NASA, still has a visible website. Their flagship mission, the Mars Science Laboratory and its Curiosity Rover, is apparently still active, operated by team members who work for JPL or Caltech or other participating institutions other than the federal government.
But as for Hubble, if there is any kind of glitch, federal civil servants will be essential to the recovery of rover operations.
NASA grounded by government shutdown
The work doesn't disappear, either. Scientists at NASA and the National Science Foundation are some of the hardest working people I know. The government shutdown means they are forbidden to do any work. They can't take their laptops home or phone into teleconferences from home, the way I might if a hurricane or snowstorm threatened Yale.
So, you might think they are having a nice (though unpaid) vacation. But actually, the same work is sitting on their desk when they get back, and it all has to get done. So it means they'll work longer hours to catch up and for most civil servant scientists, there is no such thing as overtime pay.
A NASA colleague at the Goddard Space Flight Center is designing a powerful new telescope. For the past few weeks, we've had intensive discussions with colleagues around the world about the science this telescope will be able to do.
Now, there is radio silence. His last e-mail said, "This is going to be my last e-mail before the government shutdown ends. Any work during a shutdown is deemed a violation of the Anti-Deficiency Act. You are welcome to continue to e-mail me, but I might not be able to respond until the federal government opens for business."
We are all waiting.
Russian ‘Pirates’ Offer NASA Help in Times of Crisis
MOSCOW, October 4 (RIA Novosti) - The Pirate Party of Russia has offered NASA the use of its dedicated servers to temporarily host the US space agency’s website as it has been shut down “due to the lapse in federal government funding.”
NASA was supposed to be marking its 55th birthday this week, but the US space agency gave furlough notices, not birthday invitations, to nearly all of its 18,000 employees, and began fretting about future missions as funding dried up with the US government shutdown.
“We would like to offer you bulletproof collocation or dedicated servers on our hosting platform till the end of the crisis,” the Pirate Party said in a statement posted on its website Thursday.
“We stand for Internet privacy, and as the result you would not have to worry about programs such as PRISM and other illegal activities of secret services of different countries. Your traffic, your activity and the activity of your users will be in safety,” the statement said.
The Pirate Party, founded in 2009, is active in Russia as a public movement, but the Justice Ministry has refused to register it as a political party, claiming that the name “pirate” is a reference to a criminal offense.
It claims representation in 48 regions of Russia with 5,000 applicants and at least 30,000 supporters. The stated goals of the party include promoting e-democracy, the freedom of information and the protection of personal privacy.
The party reportedly operates on a monthly budget of 6,000 rubles ($200) and a dedicated grassroots effort.
As the U.S. government shutdown grinds through its fourth day, science projects are falling like flies as they get starved of funds. And now, one of the most symbolic of scientific institutions has become the latest casualty of the political ineptitude on Capitol Hill.
Today, as of 7pm Eastern Time, the National Radio Astronomy Observatory (site offline) will shut down all of its North American facilities. This includes the Karl G. Jansky Very Large Array (VLA) and the Very Long Baseline Array (VLBA) in New Mexico, plus the Robert C. Byrd Green Bank Telescope in West Virginia. Apart from a skeleton crew that will remain behind as security for the radio antennae, the vast majority of the NRAO’s 475 employees will be laid off in an unpaid furlough.
The NRAO is funded by the National Science Foundation (site offline) and since the government shutdown on Oct. 1, the NRAO only had a week’s worth of operating funds (left over from the last fiscal year, which ended on Sept. 30) that sustained the organization through to today.
“We’re really at a dead halt,” NRAO Director Anthony Beasley told Science Insider.
Ripples of the shutdown are being felt at international radio telescopes too. The recently-completed Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, for example, is heavily funded by U.S. participation. Although the U.S. contingent has “some additional resources in the bank in Chile,” according to Beasley, that will only last for another 3-4 weeks should the the deadlock in D.C. continue that long.
Critical systems are being maintained by around 90 employees who have to weather the funding storm. Cryogenically cooled electronics, for example, need to be maintained — simply switching off these systems would be prohibitively damaging and expensive. But if the shutdown pushes into November, the NRAO may not have enough reserves to pay for its electricity bills. “This is a very difficult situation,” said Beasley.
Amid all the bad news, there are a couple of glimmers of hope for space, particularly the planetary sciences. The NASA Mars rovers Curiosity and Opportunity, for example, remain up and running (for the time being) as the scientists and engineers at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., are contractors managed by Caltech. Also, NASA’s next Mars mission, the Mars Atmosphere and Volatile Evolution (MAVEN) orbiter, was granted an emergency exception under federal law to continue preparations for its Nov. 18 launch to the red planet. If preparations were suspended, and the mission missed its primary 20-day launch window, the launch could have been bumped to 2016. The new Mars orbiter is considered critical for continued and uninterrupted communications with NASA’s surface missions.
But for the NRAO, there is little good news — North America is about to go “radio blind” and there’s little anyone can do about it.
The radio observatories shut down will impact the science community severely. Several thousand scientists use the data from NRAO installations and hundreds of them, according to Beasley, are considered “heavy” users. The radio observatories study everything from star formation, galactic evolution to the origins of our Cosmos.
Of course, the government shutdown doesn’t only affect radio observatories. All sciences that depend on government funds have been impacted; every facet of U.S. society has been hit and people are suffering as a result. Government employees have been furloughed and the public that depend on those services will have to do without. The nation’s infrastructure and economy will be greatly affected.
In the pursuit of an idiotic ideology, a very small group of politicians (with no idea about what they are fighting for, let alone the consequences) has shut down our eyes on the Cosmos. This is a reckless act that isn’t just a blip on the radar of knowledge; it will reverberate far beyond the shutdown — hurting science and the inquiring minds who investigate that science — long after the politicians decide to work for the U.S. people again.
Excerpt from President Obama's letter to federal government employees:
"Today, I am writing to simply say: Welcome back. Thank you for your service."