Microbes taken from a deep sea vent at the bottom of the Pacific Ocean can survive in an environment that would kill anything else on Earth – they live, and thrive, in water that is 130 degrees Celsius. The scientists who discovered the microbes, called Strain 121, put the creature in an autoclave, which is designed to kill all bacteria; not only did it survive, but it kept on multiplying in the high heat. The discovery helps scientists develop new theories of how life could have originated on an early Earth that was much hotter than it is today.
Image credit: Chandra
The latest image released from the Chandra X-Ray Observatory shows the centre of M17, (a.k.a. the Horseshoe Nebula) in the constellation of Sagittarius. The resolution of Chandra is so high that it can pick out the group of massive young stars which are heating the surrounding gas from 1.5 million to 7 million degrees Celsius. The stars in the nebula are only a million years old, so the nebula is too young for one of its stars to have exploded as a supernova and heated the gas.
The Chandra image reveals hot gas flowing away from massive young stars in the center of the Horseshoe Nebula, a.k.a. M17, a.k.a. the Omega Nebula. The gas temperatures range from 1.5 million degrees Celsius (2.7 million degrees Fahrenheit) to about 7 million degrees Celsius (13 million degrees F).
A group of massive young stars responsible for the activity in the nebula is located in the bright pink region near the center of the image. Chandra’s resolving power enabled astronomers to separate the contribution from these and other stars in the nebula from the diffuse emission.
Infrared Close-Up of M17
An infrared image of the Horseshoe Nebula reveals a cloud of much cooler gas and dust shaped like a horseshoe that gives the nebula its name. The hot gas shown by the Chandra image fits inside the cool gas cloud, and appears to have formed the horseshoe shape by carving a cavity in the cool gas. This activity could lead to the formation of new stars in the Horseshoe.
The stars in the Horseshoe Nebula are only about a million years old, so the nebula is too young for one of its stars to have exploded as a supernova and heated the gas. Collisions between high-speed winds of particles flowing away from the massive stars could heat the gas, or the hot gas could be produced as these winds collide with cool clouds to form bubbles of hot gas. This hot gas appears to be flowing out of the Horseshoe like champagne flows out of a bottle when the cork is removed, so it has been termed an “X-ray champagne flow.”
A comparison with other young star clusters confirms that massive young stars are responsible for hot gas clouds like the one seen in the Horseshoe Nebula. The Arches cluster, which contains many massive young stars shows this type of cloud, whereas the central regions of the Orion Nebula, which has few massive young stars, does not.
Original Source: Chandra News Release
Image credit: NASA
A NASA panel released three options for the future of the Hubble Space Telescope after its last servicing mission in 2004 or 2005 which will extend its life to 2010. The first idea is to do another servicing mission in 2010 and keep Hubble operating as long as possible. The second option is to just do the single servicing mission around 2006 and install a propulsion device which would allow NASA to de-orbit the telescope by remote control. And the third possibility is to launch a robotic mission that will attach a propulsion device so Hubble can be de-orbited later.
An independent panel of astronomers identified three options for NASA to consider for planning the transition from the Hubble Space Telescope (HST) to the James Webb Space Telescope (JWST) at the start of the next decade.
The panel, chaired by Prof. John Bahcall, Institute for Advanced Study, Princeton, N.J., chartered by NASA earlier this year, submitted their report to the agency this week.
NASA’s current plans are to extend the life of the HST to 2010 with one Space Shuttle servicing mission (SM 4) in 2005 or 2006. The plan is tentative pending the agency’s return to flight process and the availability of Shuttle missions. NASA plans to eventually remove the HST from orbit and safely bring it down into the Pacific Ocean.
“NASA is deeply appreciative to Prof. Bahcall and the panel for getting this thoughtful report to us ahead of schedule,” said Dr. Ed Weiler, NASA’s Associate Administrator for Space Science. “We have a big job to do to study the panel’s findings and consider our options, and we will respond as soon as we have time to evaluate their report,” Weiler said.
The three options presented by the HST-JWST Transition Plan Review Panel, listed in order of priority, are:
“1. Two additional Shuttle servicing missions, SM4 in about 2005 and SM5 in about 2010, in order to maximize the scientific productivity of the Hubble Space Telescope. The extended HST science program resulting from SM5 would only occur if the HST science was successful in a peer-reviewed competition with other new space astrophysics proposals.”
“2. One Shuttle servicing mission, SM4, before the end of 2006, which would include replacement of HST gyros and installing improved instruments. In this scenario, the HST could be de-orbited, after science operations are no longer possible, by a propulsion device installed on the HST during SM4 or by an autonomous robotic system.”
“3. If no Shuttle servicing missions are available, a robotic mission to install a propulsion module to bring the HST down in a controlled descent when science is no longer possible.”
In addition, the panel described various ways to ensure maximum science return from the HST if none, one or two Shuttle servicing missions are available.
“A lot of astronomers and NASA officials were astonished, when we said our report was ready just one week after our public meeting. This was possible because we reached unanimous agreement on our conclusions very quickly; remarkable when you consider there were six independent-minded scientists on the panel. Our secret is we did our homework very thoroughly. Many people helped to educate us,” Bahcall said.
For information about NASA and space science on the Internet, visit:
The HST-JWST Transition Panel report is available on the Internet at:
Information about the panel, including membership and charter, is available at:
For information about the Hubble Space Telescope on the Internet, visit:
For information about the James Webb Space Telescope on the Internet, visit:
Original Source: NASA News Release
The National Oceanic and Atmospheric Administration posted satellite images online that showed the extent of the power blackout that affected more than 50 million people late last week. The photos show the areas both before and after the lights went out and demonstrate the dramatic change in power. The images were acquired by the agency’s Defense Meteorological Satellite Program (DMSP) on August 14 at 9:03 pm EDT.
The launch of a Titan 4B rocket was delayed after 200 litres of toxic nitrogen tetroxide propellant spilled out and created a dangerous gas cloud. Fortunately, none of the workers were injured by the cloud, and it dissipated before it reached the adjacent Kennedy Space Center. It’s unknown when the Titan rocket will be ready again to launch its cargo of a National Reconnaissance Office satellite. Investigators are still determining what caused the accident.
My wife and I went for our second ultrasound last week to see how our second child is coming along. We were originally booked into a terrible ultrasound clinic (we’d been there before) but we begged our midwife to get us into a place that would treat us a little better, so we ended up at a hospital without a maternity ward – they never get a chance to look at babies. We ended up giving the ultrasound technicians a welcome break from the more boring stuff they usually have to look at. They spent almost an hour with us, examining our next baby in detail; showing us the face, the heart, and every little part of the body. If you’ve never watched an ultrasound before, I can’t recommend it enough. A static photo doesn’t do justice to the little images you see of your unborn child squirming around in the womb.
Oh yeah… we’re having a boy. 🙂
P.S. I’m headed away for vacation on Friday and won’t be back until Tuesday afternoon so there’ll be a little break in the news.
Image credit: NASA
Astronomers believe that gamma-ray bursts, the most powerful explosions in the Universe, may be generating ultrahigh-energy cosmic rays, the most energetic particles in the Universe. These cosmic rays have baffled astronomers because they’re moving faster than if they were thrown out of a supernova. Evidence gathered by NASA’s de-orbited Compton Gamma-Ray Observatory showed that in one instance of a gamma ray burst, these high-energy particles dominated the area giving a connection between them, but this is hardly enough evidence to say they’re conclusively linked.
The most powerful explosions in the universe, gamma-ray bursts, may generate the most energetic particles in the universe, known as the ultrahigh-energy cosmic rays (UHECRs), according to a new analysis of observations from NASA’s Compton Gamma-Ray Observatory.
Researchers report in the August 14 edition of Nature of a newly identified pattern in the light from these enigmatic bursts that could be explained by protons moving within a hair’s breadth of light speed.
These protons, like shrapnel from an explosion, could be UHECRs. Such cosmic rays are rare and constitute an enduring mystery in astrophysics, seemingly defying physical explanation, for they are simply far too energetic to have been generated by well-known mechanisms such as supernova explosions.
“Cosmic rays ‘forget’ where they come from because, unlike light, they are whipped about in space by magnetic fields,” said lead author Maria Magdalena Gonzalez of the Los Alamos National Laboratory in New Mexico and graduate student at the University of Wisconsin. “This result is an exciting chance to possibly see evidence of them being produced at their source.”
Gamma-ray bursts — a mystery scientists are finally beginning to unravel — can shine as brilliantly as a million trillion suns, and many may be from an unusually powerful type of exploding star. The bursts are common yet random and fleeting, lasting only seconds.
Cosmic rays are atomic particles (for example, electrons, protons or neutrinos) moving close to light speed. Lower-energy cosmic rays bombard the Earth constantly, propelled by solar flares and typical star explosions. UHECRs, with each atomic particle carrying the energy of a baseball thrown in the Major Leagues, are a hundred-million times more energetic than the particles produced in the largest human-made particle accelerators.
Scientists say the UHECRs must be generated relatively close to the Earth, for any particle traveling farther than 100 million light years would lose some of its energy by the time it reached us. Yet no local source of ordinary cosmic rays seems powerful enough to generate a UHECR.
The Gonzalez-led paper focuses not specifically on UHECR production but rather a new pattern of light seen in a gamma-ray burst. Digging deep into the Compton Observatory archives (the mission ended in 2000), the group found that a gamma-ray burst from 1994, named GRB941017, appears different from the other 2,700-some bursts recorded by this spacecraft. This burst was located in the direction of the constellation Sagitta, the Arrow, likely ten billion light years away.
What scientists call gamma rays are photons (light particles) covering a wide range of energies, in fact, over a million times wider than the energies our eyes register as the colors in a rainbow. Gonzalez’s group looked at the higher-energy gamma-ray photons. The scientists found that these types of photons dominated the burst: They were at least three times more powerful on average than the lower-energy component yet, surprisingly, thousands of times more powerful after about 100 seconds.
That is, while the flow of lower-energy photons hitting the satellite’s detectors began to ease, the flow of higher-energy photons remained steady. The finding is inconsistent with the popular “synchrotron shock model” describing most bursts. So what could explain this enrichment of higher-energy photons?
“One explanation is that ultrahigh-energy cosmic rays are responsible, but exactly how they create the gamma rays with the energy patterns we saw needs a lot of calculating,” said Dr. Brenda Dingus of LANL, a co-author on the paper. “We’ll be keeping some theorists busy trying to figure this out.”
A delayed injection of ultrahigh-energy electrons provides another way to explain the unexpectedly large high-energy gamma-ray flow observed in GRB 941017. But this explanation would require a revision of the standard burst model, said co-author Dr. Charles Dermer, a theoretical astrophysicist at the U.S. Naval Research Laboratory in Washington. “In either case, this result reveals a new process occurring in gamma-ray bursts,” he said.
Gamma-ray bursts have not been detected originating within 100 million light years from Earth, but through the eons these types of explosions may have occurred locally. If so, Dingus said, the mechanism her group saw in GRB 941017 could have been duplicated close to home, close enough to supply the UHECRs we see today.
Other bursts in the Compton Observatory archive may have exhibited a similar pattern, but the data are not conclusive. NASA’s Gamma-ray Large Area Space Telescope (GLAST), scheduled for launch in 2006, will have detectors powerful enough to resolve higher-energy gamma-ray photons and solve this mystery.
Co-authors on the Nature report also include Ph.D. graduate student Yuki Kaneko, Dr. Robert Preece, and Dr. Michael Briggs of the University of Alabama in Huntsville. This research was funded by NASA and the Office of Naval Research.
UHECRs are observed when they crash into our atmosphere, as is illustrated in the figure. The energy from the collision produces an air shower of billions of subatomic particles and flashes of ultraviolet light, which are detected by special instruments.
The National Science Foundation and international collaborators have sponsored instruments on the ground, such as the High Resolution Fly’s Eye in Utah (http://www.cosmic-ray.org/learn.html) and the Auger Observatory in Argentina (http://www.auger.org/). In addition, NASA is working with the European Space Agency to place the Extreme Universe Space Observatory (http://aquila.lbl.gov/EUSO/) on the International Space Station. The proposed OWL mission would, from orbit, look downward towards air showers, viewing a region as large as Texas.
These scientists record the flashes and take a census of the subatomic shrapnel, working backward to calculate how much energy a single particle needs to make the atmospheric cascade. They arrive at a shocking figure of 10^20 electron volts (eV) or more. (For comparison, the energy in a particle of yellow light is 2 eV, and the electrons in your television tube are in the thousand electron volt energy range.)
These ultrahigh-energy particles experience the bizarre effects predicted by Einstein’s theory of special relativity. If we could observe them coming from a remote corner of the cosmos, say a hundred million light years away, we’d have to be patient — it will take a hundred million years to complete the journey. However, if we could travel with the particles, the trip is over in less than a day due to the dilation of time of rapidly moving objects as measured by an observer.
The highest energy cosmic rays cannot even reach us if produced from distant sources, because they collide and lose energy with the cosmic microwave photons left over from the big bang. Sources of these cosmic rays must be found relatively close to us, at a distance of several hundred million light years. Stars that explode as gamma-ray bursts are found within this distance, so intensive observational efforts are underway to find gamma-ray burst remnants distinguished by radiation halos made by the cosmic rays.
Few kinds of celestial objects possess the extreme conditions required to blast particles to UHECR speeds. If gamma-ray bursts produce UHECRs, they probably do so by accelerating particles in jets of matter ejected from the explosion at close to the speed of light. Gamma-ray bursts have the power to accelerate UHECRs, but the gamma-ray bursts observed so far have been remote, billions of light years away. This doesn’t mean they can’t happen nearby, within the UHECR cutoff distance.
A leading contender for long-lived kinds of gamma-ray bursts like GRB941017 is the supernova/collapsar model. Supernovae happen when a star many times more massive than the Sun exhausts its fuel, causing its core to collapse under its own gravity while its outer layers are blown off in an immense thermonuclear explosion. Collapsars are a special type of supernova where the core is so massive it collapses into a black hole, an object so dense that nothing, not even light, can escape its gravity within the black hole’s event horizon. However, observations indicate black holes are sloppy eaters, ejecting material that passes near, but does not cross, their event horizons.
In a collapsar, the star’s core forms a disk of material around the newly formed black hole, like water swirling around a drain. The black hole consumes most of the disk, but some matter is blasted in jets from the poles of the black hole. The jets tear through the collapsing star at close to the speed of light, and then punch through gas surrounding the doomed star. As the jets crash into the interstellar medium, they create shock waves and slow down. Internal shocks also form in the jets as their leading edges slow and are slammed from behind by a stream of high-speed matter. The shocks accelerate particles that generate gamma rays; they could also accelerate particles to UHECR speeds, according to the team.
“It’s like bouncing a ping pong ball between a paddle and a table,” said Dingus. “As you move the paddle closer to the table, the ball bounces faster and faster. In a gamma-ray burst, the paddle and the table are shells ejected in the jet. Turbulent magnetic fields force the particles to ricochet between the shells, accelerating them to almost the speed of light before they break free as UHECRs.”
Detection of neutrinos from gamma-ray bursts would clinch the case for cosmic ray acceleration by gamma-ray bursts. Neutrinos are elusive particles made when high-energy protons collide with photons. Neutrinos have no electrical charge, so still point back to the direction of their source.
The National Science Foundation is currently building IceCube (http://icecube.wisc.edu/), a cubic kilometer detector located in the ice under the South Pole, to search for neutrino emission from gamma-ray bursts. However, the characteristics of nature’s highest-energy particle accelerators remain an enduring mystery, though acceleration by the exploding stars that make gamma-ray bursts has been in favor ever since Mario Vietri (Universita di Roma) and Eli Waxman (Weizmann Institute) proposed it in 1995.
The team believes that while other explanations are possible for this observation, the result is consistent with UHECR acceleration in gamma-ray bursts. They saw both low-energy and high-energy gamma rays in the GRB941017 explosion. The low-energy gamma rays are what scientists expect from high-speed electrons being deflected by intense magnetic fields, while the high-energy rays are what’s expected if some of the UHECRs produced in the burst crash into other photons, creating a shower of particles, some of which flash to produce the high-energy gamma rays when they decay.
The timing of the gamma-ray emission is also significant. The low-energy gamma rays faded away relatively quickly, while the high-energy gamma rays lingered. This makes sense if two different classes of particles – electrons and the protons of the UHECRs – are responsible for the different gamma rays. “It’s much easier for electrons than protons to radiate their energy. Therefore, the emission of low-energy gamma rays from electrons would be shorter than the high-energy gamma rays from the protons,” said Dingus.
The Compton Gamma Ray Observatory was the second of NASA’s Great Observatories and the gamma-ray equivalent to the Hubble Space Telescope and the Chandra X-ray Observatory. Compton was launched aboard the Space Shuttle Atlantis in April 1991, and at 17 tons, was the largest astrophysical payload ever flown at that time. At the end of its pioneering mission, Compton was deorbited and re-entered the Earth’s atmosphere on June 4, 2000.
Original Source: NASA News Release
Image credit: NASA
The Canadian Space Agency’s SCISAT satellite was successfully launched Wednesday morning on board a Pegasus XL rocket. The L-1011 carrier aircraft deployed the three-stage Pegasus rocket at 0210 GMT (22:10 EDT Tuesday) at 12,000 metres, which then blasted up to a 650 km polar orbit. During its two-year mission, SCISAT will help a team of international scientists improve their understanding of ozone layer depletion – especially over Canada and the Arctic.
SAINT-HUBERT, Aug. 13 /CNW Telbec/ – The Canadian Space Agency (CSA)
today confirmed the successful launch of its SCISAT satellite last night from
NASA’s launch facilities near Lompoc, California. During its two-year mission,
SCISAT will help a team of Canadian and international scientists improve their
understanding of the depletion of the ozone layer, with a special emphasis on
the changes occurring over Canada and in the Arctic.
“This leading-edge Canadian technology will improve our scientific
understanding of the complex chemical changes occurring in the upper
atmosphere, particularly in the far north”, said Mr. Allan Rock, Minister of
Industry.” The SCISAT mission illustrates how Canadian universities,
government and industry can work together to put innovative technologies at
the service of scientific research,” added Minister Rock.
SCISAT was launched yesterday at 19:10 PDT, approximately 160 km offshore
from the Vandenberg Air Force Base. The 150 kg satellite was packed in the
nose of a Pegasus XL rocket dropped at 40,000 feet over the Pacific Ocean from
a Lockeed-1011 aircraft. The satellite was successfully brought to its 650 km-
high polar orbit by the 3-stage Pegasus rocket.
“SCISAT sets a milestone in Canadian space science,” said Marc Garneau,
President of the CSA. “Following the MOST space telescope launched in June,
SCISAT is the second science satellite successfully placed in orbit by Canada
in the last 45 days. This illustrates the growing importance of space science
for Canada and for the Canadian Space Program.”
A scientific team of researchers from around the world, lead by Professor
Peter Bernath of the University of Waterloo, will participate in the
Atmospheric Chemistry Experiment (ACE) which aims to measure and understand
the chemical processes that control the distribution of ozone in the Earth’s
atmosphere, particularly at high latitudes. The data, recorded as SCISAT
orbits the Earth, will provide scientists with improved measurements relating
to global ozone processes. It will also help policy makers assess existing
environmental policy and develop protective measures for improving the health
of our atmosphere and preventing further ozone depletion.
The primary scientific instrument on board SCISAT is a Fourier Transform
Spectrometer (ACE-FTS), built by ABB of Qu?bec City. A second instrument named
MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and
Troposphere Retrieved by Occultation), built by EMS Technologies of Ottawa,
will also fly on the satellite. Dr. Tom McElroy of Environment Canada is the
principal investigator for MAESTRO, and will be supported by Professor James
Drummond of the University of Toronto.
For more background information on the SCISAT mission, please visit the
CSA website at: http://www.space.gc.ca/scisat1
Original Source: CSA News Release
With Mars approaching, people have been a lot more interested in getting to know their night sky. One of the best resources for this is a website called Skymaps.com. It offers a free map of the night sky from both the Northern and Southern hemispheres which you can download and print off each month. It also has a calendar of astronomy-related events happening for the month and a list of objects which are visible with the naked eye/binoculars/telescope. The best thing to do is sign up for the monthly newsletter so you’re notified as soon as a new map is ready.
Image credit: NASA
Berto Monard, an amateur astronomer from South Africa was lucky enough to spot the afterglow from a powerful gamma-ray burst – beating professional astronomers to the target. The 40-second-long burst was discovered by NASA’s HETE spacecraft, which provided Monard rough coordinates of where to look. He was able to provide the astronomy community with a precise location so they can follow up days or weeks later to try and determine what actually caused the explosion.
Armed with a 12-inch telescope, a computer, and a NASA email alert, Berto Monard of South Africa has become the first amateur astronomer to discover an afterglow of a gamma-ray burst, the most powerful explosion known in the Universe.
The discovery highlights the ease in tapping into NASA’s burst alert system, as well as the increasing importance that astronomy enthusiasts play in helping scientists understand fleeting and random events, such as star explosions and gamma-ray bursts.
This 40-second-long burst was detected by NASA’s High-Energy Transient Explorer (HETE) on July 25. Monard’s positioning of the lingering afterglow, and thus burst location, has given way to precision follow-up study, an opportunity that very well might have been missed: At the time of the burst, thousands of professional astronomers were attending the International Astronomical Union conference in Sydney, Australia, far away from their observatories.
“I have seen a multitude of stars and galaxies and even supernovae, but this gamma-ray burst afterglow is among the most ancient light that has ever graced my telescope,” Monard said. “The explosion that caused this likely occurred billions of years ago, before the Earth was formed.”
Gamma-ray bursts, many of which now appear to be massive star explosions billions of light years away, only last for a few milliseconds to upwards of a minute. Prompt identification of an afterglow, which can last for hours to days in lower-energy light such as X ray and optical, is crucial for piecing together the explosion that caused the burst.
Monard notified the pros of the burst location within seven hours of the HETE detection. The Interplanetary Network (IPN), comprising six orbiting gamma-ray detectors, confirmed the location shortly thereafter.
Because of the nature of gamma-ray light, which cannot be focused like optical light, HETE locates bursts to only within a few arcminutes. (An arcminute is about the size of an eye of a needle held at arm’s length.) Most gamma-ray bursts are exceedingly far, so myriad stars and galaxies fill that tiny circle. Without prompt localization of a bright and fading afterglow, scientists have great difficulty locating the gamma-ray burst
location days or weeks later.
The study of gamma-ray bursts (and increasing ease of amateur participation) comes through two innovations: faster burst detectors like HETE and a near-instant information relay system called the Gamma-ray Burst Coordinates Network, or GCN, which is located at NASA Goddard Space Flight Center in Greenbelt, Md.
The typical pattern follows: HETE detects a burst and, within a few seconds to about a minute, relays a location to the GCN. Instantly, the automated GCN notifies scientists and amateur astronomers worldwide about the burst event via email, pagers, and a Web site.
Monard is a member of the American Association of Variable Star Observers (AAVSO). This organization operates the AAVSO International High Energy Network, which acts as a liaison between the amateur and the professional communities. Monard essentially used GCN information passed through the AAVSO and other network groups and turned his telescope to the location determined by HETE.
“In the past two years, HETE has opened the door wide for rapid follow-up studies by professional astronomers,” said HETE Principal Investigator George Ricker of MIT. “Now, with GRB030725, the worldwide community of dedicated and expert amateur astronomers coordinated through the AAVSO is leaping through that door to join the fun.”
Monard, a Belgian national living in South Africa, has other discoveries under his belt, including ten supernovae and several outbursts from neutron star systems, as part of his participation with the worldwide Center for Backyard Astrophysics network and the Variable Star Network.
The AAVSO, founded in 1911, is a non-profit, scientific organization with members in 46 countries. It coordinates, compiles, digitizes and disseminates observations on stars that change in brightness (variable stars) to researchers and educators worldwide. Its International High Energy Network was created with cooperation from NASA.
HETE was built by the Massachusetts Institute of Technology under NASA’s Explorer Program. HETE is a collaboration among NASA, MIT, Los Alamos National Laboratory; France’s Centre National d’Etudes Spatiales, Centre d’Etude Spatiale des Rayonnements, and Ecole Nationale Superieure de l’Aeronautique et de l’Espace; and Japan’s Institute of Physical and Chemical Research (RIKEN). The science team includes members from the University of California (Berkeley and Santa Cruz) and the University of Chicago, as well as from Brazil, India and Italy.