New Horizons Team Sticking to Original Flight Plan at Pluto

 Unless significant new hazards are found, expect NASA’s New Horizons spacecraft to stay on its original course past Pluto and its moons, after mission managers concluded that the danger posed by dust and debris in the Pluto system is less than they once feared. The New Horizons team recently completed an 18-month study of potential impact hazards – mostly dust created by objects hitting Pluto’s small satellites – the spacecraft would face as it speeds some 30,000 miles per hour (more than 48,000 kilometers per hour) past Pluto in July 2015.

 “We found that loss of the New Horizons mission by dust impacting the spacecraft is very unlikely, and we expect to follow the nominal, or baseline, mission timeline that we’ve been refining over the past few years,” says New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory. “Still, we’ll be ready with two alternative timelines, in the event that the impact risk turns out to be greater than we think.”

 Those alternate plans (called SHBOTs, short for Safe Haven by Other Trajectories) are being developed should new information – gathered from New Horizons camera observations during the approach to Pluto, for example, or new dust-dynamics analyses – indicate less-than-smooth sailing for New Horizons.

 One plan, the Generic Inner SHBOT, is essentially the same as baseline trajectory, but with the spacecraft turned so that its 7-foot dish antenna faces the incoming dust particles; this “Antenna-to-Ram” (or ATR) configuration would protect the spacecraft underneath. The Deep Inner SHBOT also employs ATR protection, but would additionally dip the trajectory to within just 3,000 kilometers (nearly 1,900 miles) of Pluto’s surface, where atmospheric drag tends to sweep out lingering dust.

 New Horizons managers recently presented their impact-hazard outlook and if-necessary mitigation plans to an independent NASA review panel and to the NASA Science Mission Directorate Program Management Council &ndash receiving endorsements from both.

 New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, says the mission team is now finalizing plans for the Pluto encounter. In early July, the team will rehearse the most critical nine-day segment of the baseline encounter plan, putting itself and the spacecraft through the paces of the flight toward and just past Pluto and its moons.

 Stern adds that the spacecraft remains on target for a close approach to Pluto in 2015, all subsystems are performing nominally, and “the anticipated science observations will revolutionize our understanding of dwarf planets and the Kuiper belt, and excite a whole new generation of the public to the first reconnaissance of a planet on the very frontier of our solar system.” Credit: pluto.jhuapl.edu

Arecibo Radar Sees Asteroid 1998 QE2 and Moon

Arecibo Observatory catches the most detailed radar images ever of asteroid 1998 QE2 and its newly discovered moon as they safely pass our planet. Arecibo Observatory continues to take radar images of asteroid 1998 QE2 and its moon as the space rock sails safely passed earth this week. The images show a dark cratered asteroid 3 kilometers across (1.9 miles) with a companion moon 750 meters (2,500 feet) in size.

Texas tourism may go suborbital

 Only about 500 people have traveled to space, and few have traveled to space commercially. You can expect that to change — and Texas could be involved in a big way. The last decade has seen the first leisure travelers go to space. Since 2001, seven individuals have purchased eight orbital flights — one passenger flew twice — for up to $35 million per flight. Austin software and gaming mogul Richard Garriott was one of them.

 Europe’s largest spaceship reaches its orbital port

 ESA’s fourth Automated Transfer Vehicle, Albert Einstein, completed a flawless rendezvous with the International Space Station on 15 June when it docked smoothly with orbital outpost at 14:07 GMT (16:07 CEST). The Automated Transfer Vehicle (ATV) is now connected to the Space Station. “Bravo Europe, bravo ESA, bravo ATV.

Thank you Member States, thank you industry, thank you CNES, thank you Russian partner,” commented Jean-Jacques Dordain, Director General of ESA. “With the fourth ATV now ready to support and supply the Space Station with essential supplies and scientific experiments, ESA again proves itself to be a reliable partner in the international station upon which the future can be developed.”

Former army boss Walt Natynczyk tapped to lead Canadian Space Agency

Chinese astronauts warm-up work in space module

 Chinese astronauts installed new floor boards in the orbiting Tiangong-1 space module on Friday morning, according to the Beijing Aerospace Control Center. The maneuver was a warm-up task for the three-person crew that is expected to carry out scientific experiments and technical tests during the remainder of their 15-day journey. Video clips show the three astronauts, including China’s second female astronaut in space, wearing blue jumpsuits while installing the floor boards after receiving instructions from the ground control centre.

Russia to Unveil New Piloted Spacecraft at MAKS Airshow

 A mock-up of Russia’s new piloted spacecraft will be showcased in August at the MAKS airshow near Moscow, Russia’s space chief said Friday. The new craft, being developed by the Russian spaceship manufacturer RKK Energia, is expected to make its maiden flight in 2018. “At the MAKS airshow, we will soon see the mock-up of the spaceship, which will fly in 2018,” space chief Vladimir Popovkin said at a meeting with President Vladimir Putin and Russian cosmonauts.

Testing times for SpaceX’s new Falcon 9 v.1.1

Engineers at SpaceX’s Rocket Development and Test Facility in McGregor, Texas are continuing to conduct a series of firings of the company’s upgraded Falcon 9 v.1.1 launch vehicle – which is scheduled to debut this summer. Testing on the core stage – with its new Merlin 1D engines – has proven to be challenging, due to a number of aborted firings. SpaceX have successfully flown the Falcon 9 v1.0 – powered by nine SpaceX Merlin 1C engines arranged in a “tic-tac-toe” pattern – via the first five F9 launches, including four launches of the Dragon spacecraft – three of which resulted in a successful mission to the International Space Station (ISS).

Mars Rover Opportunity Trekking Toward More Layers

Approaching its 10th anniversary of leaving Earth, NASA’s Mars Exploration Rover Opportunity is on the move again, trekking to a new study area still many weeks away. The destination, called “Solander Point,” offers Opportunity access to a much taller stack of geological layering than the area where the rover has worked for the past 20 months, called “Cape York.” Both areas are raised segments of the western rim of Endeavour Crater, which is about 14 miles (22 kilometers) in diameter.

 ”Getting to Solander Point will be like walking up to a road cut where you see a cross section of the rock layers,” said Ray Arvidson of Washington University, St. Louis, deputy principal investigator for the mission.

Several types of downhill flow features have been observed on Mars. This image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter is an example of a type called “linear gullies.” Image credit: NASA/JPL-Caltech/Univ. of Arizona

Astronomers Gear Up to Discover Earth-Like Planets

 If one looks only for the shiniest pennies in the fountain, chances are one misses most of the coins because they shimmer less brightly. This, in a nutshell, is the conundrum astronomers face when searching for Earth-like planets outside our solar system. Astronomers at the University of Arizona are part of an international team of exoplanets hunters developing new technology that would dramatically improve the odds of discovering planets with conditions suitable for life – such as having liquid water on the surface. The team presented its results at a scientific conference sponsored by the International Astronomical Union in Victoria, British Columbia.

 Terrestrial planets orbiting nearby stars often are concealed by vast clouds of dust enveloping the star and its system of planets. Our solar system, too, has a dust cloud, which consists mostly of debris left behind by clashing asteroids and exhaust spewing out of comets when they pass by the sun. “Current technology allows us to detect only the brightest clouds, those that are a few thousand times brighter than the one in our solar system,” said Denis Defrère, a postdoctoral fellow in the UA’s department of astronomy and instrument scientist of the Large Binocular Telescope Interferometer, or LBTI.

 

MOON RADIATION FINDINGS MAY REDUCE HEALTH RISKS TO ASTRONAUTS

Space scientists from the University of New Hampshire (UNH) and the Southwest Research Institute (SwRI) report that data gathered by NASA’s Lunar Reconnaissance Orbiter (LRO) show lighter materials like plastics provide effective shielding against the radiation hazards faced by astronauts during extended space travel. The finding could help reduce health risks to humans on future missions into deep space.

Aluminum has always been the primary material in spacecraft construction, but it provides relatively little protection against high-energy cosmic rays and can add so much mass to spacecraft that they become cost-prohibitive to launch.

The scientists have published their findings online in the American Geophysical Union journal Space Weather. Titled “Measurements of Galactic Cosmic Ray Shielding with the CRaTER Instrument,” the work is based on observations made by the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on board the LRO spacecraft. Lead author of the paper is Cary Zeitlin of the SwRI Earth, Oceans, and Space Department at UNH. Co-author Nathan Schwadron of the UNH Institute for the Study of Earth, Oceans, and Space is the principal investigator for CRaTER.

Says Zeitlin, “This is the first study using observations from space to confirm what has been thought for some time — that plastics and other lightweight materials are pound-for-pound more effective for shielding against cosmic radiation than aluminum. Shielding can’t entirely solve the radiation exposure problem in deep space, but there are clear differences in effectiveness of different materials.”

The plastic-aluminum comparison was made in earlier ground-based tests using beams of heavy particles to simulate cosmic rays. “The shielding effectiveness of the plastic in space is very much in line with what we discovered from the beam experiments, so we’ve gained a lot of confidence in the conclusions we drew from that work,” says Zeitlin. “Anything with high hydrogen content, including water, would work well.”

The space-based results were a product of CRaTER’s ability to accurately gauge the radiation dose of cosmic rays after passing through a material known as “tissue-equivalent plastic,” which simulates human muscle tissue. Prior to CRaTER and recent measurements by the Radiation Assessment Detector (RAD) on the Mars rover Curiosity, the effects of thick shielding on cosmic rays had only been simulated in computer models and in particle accelerators, with little observational data from deep space.

The CRaTER observations have validated the models and the ground-based measurements, meaning that lightweight shielding materials could safely be used for long missions, provided their structural properties can be made adequate to withstand the rigors of spaceflight.

Since LRO’s launch in 2009, the CRaTER instrument has been measuring energetic charged particles — particles that can travel at nearly the speed of light and may cause detrimental health effects — from galactic cosmic rays and solar particle events. Fortunately, Earth’s thick atmosphere and strong magnetic field provide adequate shielding against these dangerous high-energy particles.

ZOË ROBOT RETURNS TO CHILE’S ATACAMA DESERT TO SEARCH FOR SUBSURFACE LIFE

The autonomous, solar-powered Zoë, which became the first robot to map microbial life during a 2005 field expedition in Chile’s Atacama Desert, is heading back to the world’s driest desert this month on a NASA astrobiology mission led by Carnegie Mellon University and the SETI Institute. This time, Zoë is equipped with a one-meter drill to search for subsurface life.

As before, Zoë will be testing technologies and techniques that will be necessary for exploring life on Mars. NASA’s Curiosity rover is finding life-friendly areas on the Red Planet, and the space agency now is deciding how best to equip a rover set to follow in Curiosity’s tracks in 2020.

“Direct evidence of life, if it exists, is more likely underground, beyond the current reach of rovers,” said David Wettergreen, research professor in Carnegie Mellon’s Robotics Institute and the principal investigator for the Life in the Atacama project. So Zoë has been fitted with a drill made by Honeybee Robotics than can bore deep into the ground. “Chances improve with greater depth but we are first developing one-meter capability and integrating with a mobile robot,” Wettergreen added.

The robot’s auger will dredge up soil samples that can be analyzed with several on-board instruments. One of these is the Mars Microbeam Raman Spectrometer, an early candidate for the 2020 Mars mission, which can analyze mineral and elemental composition of soil.

“We are measuring the subsurface habitats in which life survives, determining what factors are important, and learning about one of the Earth’s harshest climates,” said planetary geologist Nathalie Cabrol, senior research scientist at the Carl Sagan Center of the SETI Institute, who is the science lead for the Life in the Atacama project.

In addition to Honeybee, the project includes collaborators at Universidad Catolica del Norte in Chile, the University of Tennessee, Washington University and the Jet Propulsion Laboratory. The project is supported by a $3 million grant from NASA.

Last year, in the first year of the three-year project, Cabrol, Wettergreen and other team members went to the Atacama without Zoë, visiting a variety of sites. They used a neutron detection instrument that measures hydrogen abundance to quantify moisture, several spectrometers to measure mineral and elemental composition of soils, and other instruments. They bored holes with hand-held drilling equipment and manually operated the instruments.

The findings from the first-year experiments will provide a comparison to what the robot can do automatically during field experiments this year and next.

The expedition confirmed that microorganisms are present in the Atacama soils, though extremely scarce. It also discovered a problem with the neutron detection instrument, called the Dynamic Albedo of Neutrons (DAN). The radioactive tritium in its neutron generator had decayed to the point that it could no longer function. Wettergreen said NASA had planned to use an identical DAN instrument aboard Curiosity later in its mission, but changed tempo once the Atacama discovery showed that the instrument would not survive as long as planned.

Zoë will undergo engineering tests in Chile this week in preparation for two weeks of scientific field experiments. The scientific trek will begin June 17 and will cover a 30-50 kilometer traverse in the hyper-arid core of the desert. One or two drilling operations are anticipated each day. The scientists plan to post updates during the trek on the project website: http://www.frc.ri.cmu.edu/projects/atacama/

Though previous expeditions with Zoë have emphasized technology for autonomous operation of the robot, Wettergreen said the focus this time will be on gathering scientific data. “Now, we think of the robot as a tool to collect specific data from specific locations, rather than as a machine that drives around,” he said.

One technical goal is to have multiple days of completely autonomous operation executing the scientists’ plans regarding where they want the robot to go and how much data to collect at each point, then hibernating for the night and automatically resuming its plan when the Sun returns.

Zoë is a four-wheeled robot, about 9 feet long and 6 feet wide. A solar array measuring three square meters lies flat atop its body, generating power with high-efficiency gallium arsenide solar cells. Because it is totally solar-powered, the robot operates primarily during the day, though it may do some processing of scientific samples overnight.

SHINING A LIGHT ON COOL POOLS OF GAS IN THE GALAXY

Newly formed stars shine brightly, practically crying out, “Hey, look at me!” But not everything in our Milky Way galaxy is easy to see. The bulk of material between the stars in the galaxy — the cool hydrogen gas from which stars spring — is nearly impossible to find.

A new study from the Hershel Space Observatory, a European Space Agency mission with important NASA participation, is shining a light on these hidden pools of gas, revealing their whereabouts and quantities. In the same way that dyes are used to visualize swirling motions of transparent fluids, the Herschel team has used a new tracer to map the invisible hydrogen gas.

The discovery reveals that the reservoir of raw material for making stars had been underestimated before — almost by one third — and extends farther out from our galaxy’s center than known before.

“There is an enormous additional reservoir of material available to form new stars that we couldn’t identify before,” said Jorge Pineda of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of a new paper on the findings published in the journal Astronomy and Astrophysics.

“We had to go to space to solve this mystery because our atmosphere absorbs the specific radiation we wanted to detect,” said William Langer of JPL, principal investigator of the Herschel project to map the gas. “We also needed to see far-infrared light to pinpoint the location of the gas. For both these reasons, Herschel was the only telescope for the job.”

Stars are created from clouds of gas, made of hydrogen molecules. The first step in making a star is to squeeze gas together enough that atoms fuse into molecules. The gas starts out sparse but, through the pull of gravity and sometimes other constricting forces, it collects and becomes denser. When the hydrogen gets dense enough, nuclear fusion takes place and a star is born, shining with starlight.

Astronomers studying stars want to follow this journey, from a star’s humble beginnings as a cloud of molecules to a full-blown blazing orb. To do so requires mapping the distribution of the stellar hydrogen fuel across the galaxy. Unfortunately, most hydrogen molecules in space are too cold to give off any visible light. They lurk unseen by most telescopes.

For decades, researchers have turned to a tracer molecule called carbon monoxide, which goes hand-in-hand with the hydrogen molecules, revealing their location. But this method has limitations. In regions where the gas is just beginning to pool — the earliest stage of cloud formation — there is no carbon monoxide.

“Ultraviolet light destroys the carbon monoxide,” said Langer. “In the space between stars, where the gas is very thin, there is not enough dust to shield molecules from destruction by ultraviolet light.”

A different tracer — ionized carbon — does, however, linger in these large but relatively empty spaces, and can be used to pin down the hydrogen molecules. Researchers have observed ionized carbon from space before, but Herschel has, for the first time, provided a dramatically improved geographic map of its location and abundance in the galaxy.

“Thanks to Herschel’s incredible sensitivity, we can separate material moving at different speeds,” said Paul Goldsmith, a co-author and the NASA Herschel Project Scientist at JPL. “We finally can get the whole picture of what’s available to make future generations of stars.”

STACKING UP A CLEARER PICTURE OF THE UNIVERSE

Researchers from the International Centre for Radio Astronomy Research (ICRAR) have proven a new technique that will provide a clearer picture of the universe’s history and be used with the next generation of radio telescopes such as the Square Kilometre Array (SKA).

In research published today in the Monthly Notices of the Royal Astronomical Society [preprint: http://arxiv.org/abs/1305.1968], ICRAR PhD Candidate Jacinta Delhaize has studied distant galaxies en masse to determine one of their important properties — how much hydrogen they contain — by ‘stacking’ their signals.

As astronomers use telescopes to peer into space, they get a glimpse at what the universe was like in the past, often billions of years ago. This allows them to compare the present state of the universe to its history and map how it’s changed over time, giving clues to its origins and future.

“Distant, younger, galaxies look very different to nearby galaxies, which means that they’ve changed, or evolved, over time,” said Delhaize. “The challenge is to try and figure out what physical properties within the galaxy have changed, and how and why this has happened.”

Delhaize said that one of the pieces of the puzzle is hydrogen gas and how much of it galaxies contained through the history of the universe.

“Hydrogen is the building block of the universe, it’s what stars form from and what keeps a galaxy ‘alive’,” said Delhaize.

“Galaxies in the past formed stars at a much faster rate than galaxies now. We think that past galaxies had more hydrogen, and that might be why their star formation rate is higher.

Delhaize and her supervisors set out to observe how much hydrogen was in far away galaxies, but the faint radio signals of this distant hydrogen gas are almost impossible to detect directly. This is where the new stacking technique comes in.

To gather enough data for her research, Delhaize combined weak signals from thousands of individual galaxies, stacking them to produce a strong averaged signal that is easier to study.

“What we are trying to achieve with stacking is sort of like detecting a faint whisper in a room full of people shouting,” said Delhaize. “When you combine together thousands of whispers, you get a shout that you can hear above a noisy room, just like combining the radio light from thousands of galaxies to detect them above the background.”

The research used CSIRO’s Parkes radio telescope to survey a large section of the sky for 87 hours, collecting signals from hydrogen over an unmatched volume of space and up to two billion years back in time.

“The Parkes telescope views a big section of the sky at once, so it was quick to survey the large field we chose for our study,” said ICRAR Deputy Director and Jacinta’s supervisor, Professor Lister Staveley-Smith.

Delhaize said observing such a large volume of space meant that she could accurately calculate the average amount of hydrogen in galaxies at a certain distance from Earth, corresponding to a particular period in the universe’s history. This provides information that can be used in simulations of the universe’s evolution and clues to how galaxies formed and changed over time.

Next generation telescopes like the international Square Kilometre Array (SKA) and CSIRO’s Australian SKA Pathfinder (ASKAP) will be able to observe even larger volumes of the universe with higher resolution.

“That makes them fast, accurate and perfect for studying the distant universe. We can use the stacking technique to get every last piece of valuable information out of their observations,” said Delhaize. “Bring on ASKAP and the SKA!”

BLACK HOLE NAPS AMIDST STELLAR CHAOS

Nearly a decade ago, NASA’s Chandra X-ray Observatory caught signs of what appeared to be a black hole snacking on gas at the middle of the nearby Sculptor galaxy. Now, NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR), which sees higher-energy X-ray light, has taken a peek and found the black hole asleep.

“Our results imply that the black hole went dormant in the past 10 years,” said Bret Lehmer of the Johns Hopkins University, Baltimore, and NASA’s Goddard Space Flight Center, Greenbelt, Md. “Periodic observations with both Chandra and NuSTAR should tell us unambiguously if the black hole wakes up again. If this happens in the next few years, we hope to be watching.” Lehmer is lead author of a new study detailing the findings to appear in the Astrophysical Journal.

The slumbering black hole is about 5 million times the mass of our Sun. It lies at the center of the Sculptor galaxy, also known as NGC 253, a so-called starburst galaxy actively giving birth to new stars. At 13 million light-years away, this is one of the closest starbursts to our own galaxy, the Milky Way.

The Milky Way is all around more quiet than the Sculptor galaxy. It makes far fewer new stars, and its behemoth black hole, about 4 million times the mass of our Sun, is also snoozing.

“Black holes feed off surrounding accretion disks of material. When they run out of this fuel, they go dormant,” said co-author Ann Hornschemeier of Goddard. “NGC 253 is somewhat unusual because the giant black hole is asleep in the midst of tremendous star-forming activity all around it.”

The findings are teaching astronomers how galaxies grow over time. Nearly all galaxies are suspected to harbor supermassive black holes at their hearts. In the most massive of these, the black holes are thought to grow at the same rate that new stars form, until blasting radiation from the black holes ultimately shuts down star formation. In the case of the Sculptor galaxy, astronomers do not know if star formation is winding down or ramping up.

“Black hole growth and star formation often go hand-in-hand in distant galaxies,” said Daniel Stern, a co-author and NuSTAR project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “It’s a bit surprising as to what’s going on here, but we’ve got two powerful complementary X-ray telescopes on the case.”

Chandra first observed signs of what appeared to be a feeding supermassive black hole at the heart of the Sculptor galaxy in 2003. As material spirals into a black hole, it heats up to tens of millions of degrees and glows in X-ray light that telescopes like Chandra and NuSTAR can see.

Then, in September and November of 2012, Chandra and NuSTAR observed the same region simultaneously. The NuSTAR observations — the first-ever to detect focused, high-energy X-ray light from the region — allowed the researchers to say conclusively that the black hole is not accreting material. NuSTAR launched into space in June of 2012.

In other words, the black hole seems to have fallen asleep. Another possibility is that the black hole was not actually awake 10 years ago, and Chandra observed a different source of X-rays. Future observations with both telescopes may solve the puzzle.

“The combination of coordinated Chandra and NuSTAR observations is extremely powerful for answering questions like this,” said Lou Kaluzienski, NuSTAR Program Scientist at NASA Headquarters in Washington. “Now, we can get all sides of the story.”

The observations also revealed a smaller, flaring object that the researchers were able to identify as an “ultraluminous X-ray source,” or ULX. ULXs are black holes feeding off material from a partner star. They shine more brightly than typical stellar-mass black holes generated from dying stars, but are fainter and more randomly distributed than the supermassive black holes at the centers of massive galaxies. Astronomers are still working to understand the size, origins and physics of ULXs.

“These stellar-mass black holes are bumping along near the center of this galaxy,” said Hornschemeier. “They tend to be more numerous in areas where there is more star-formation activity.”

If and when the Sculptor’s slumbering giant does wake up in the next few years amidst all the commotion, NuSTAR and Chandra will monitor the situation. The team plans to check back on the system periodically.

A VIDEO MAP OF MOTIONS IN THE NEARBY UNIVERSE

An international team of researchers, including University of Hawaii at Manoa astronomer Brent Tully, has mapped the motions of structures of the nearby universe in greater detail than ever before. The maps are presented as a video, which provides a dynamic three-dimensional representation of the universe through the use of rotation, panning, and zooming. The video was announced last week at the conference “Cosmic Flows: Observations and Simulations” in Marseille, France, that honored the career and 70th birthday of Tully.

The Cosmic Flows project has mapped visible and dark matter densities around our Milky Way galaxy up to a distance of 300 million light-years.

The team includes Helene Courtois, associate professor at the University of Lyon, France, and associate researcher at the Institute for Astronomy (IfA), University of Hawaii (UH) at Manoa, USA; Daniel Pomarede, Institute of Research on Fundamental Laws of the universe, CEA/Saclay, France; Brent Tully, IfA, UH Manoa; and Yehuda Hoffman, Racah Institute of Physics, University of Jerusalem, Israel.

The large-scale structure of the universe is a complex web of clusters, filaments, and voids. Large voids — relatively empty spaces — are bounded by filaments that form superclusters of galaxies, the largest structures in the universe. Our Milky Way galaxy lies in a supercluster of 100,000 galaxies.

Just as the movement of tectonic plates reveals the properties of Earth’s interior, the movements of the galaxies reveal information about the main constituents of the universe: dark energy and dark matter. Dark matter is unseen matter whose presence can be deduced only by its effect on the motions of galaxies and stars because it does not give off or reflect light. Dark energy is the mysterious force that is causing the expansion of the universe to accelerate.

The video captures with precision not only the distribution of visible matter concentrated in galaxies, but also the invisible components, the voids and the dark matter. Dark matter constitutes 80 percent of the total matter of our universe and is the main cause of the motions of galaxies with respect to each other. This precision 3-D cartography of all matter (luminous and dark) is a substantial advance.

The correspondence between wells of dark matter and the positions of galaxies (luminous matter) is clearly established, providing a confirmation of the standard cosmological model. Through zooms and displacements of the viewing position, this video follows structures in three dimensions and helps the viewer grasp relations between features on different scales, while retaining a sense of orientation.

The scientific community now has a better representation of the moving distribution of galaxies around us and a valuable tool for future research.

 NASA’S HUBBLE UNCOVERS EVIDENCE OF FARTHEST PLANET FORMING FROM ITS STAR

Astronomers using NASA’s Hubble Space Telescope have found compelling evidence of a planet forming 7.5 billion miles away from its star, a finding that may challenge current theories about planet formation.

Of the almost 900 planets outside our solar system that have been confirmed to date, this is the first to be found at such a great distance from its star. The suspected planet is orbiting the diminutive red dwarf TW Hydrae, a popular astronomy target located 176 light-years away from Earth in the constellation Hydra the Sea Serpent.

Hubble’s keen vision detected a mysterious gap in a vast protoplanetary disk of gas and dust swirling around TW Hydrae. The gap is 1.9 billion miles wide, and the disk is 41 billion miles wide. The gap’s presence likely was caused by a growing, unseen planet that is gravitationally sweeping up material and carving out a lane in the disk, like a snow plow.

The planet is estimated to be relatively small, at 6 to 28 times more massive than Earth. Its wide orbit means it is moving slowly around its host star. If the suspected planet were orbiting in our solar system, it would be roughly twice Pluto’s distance from the Sun.

Planets are thought to form over tens of millions of years. The buildup is slow, but persistent as a budding planet picks up dust, rocks, and gas from the protoplanetary disk. A planet 7.5 billion miles from its star should take more than 200 times longer to form than Jupiter did at its distance from the Sun because of its much slower orbital speed and the deficiency of material in the disk. Jupiter is 500 million miles from the Sun and it formed in about 10 million years.

TW Hydrae is only 8 million years old, making it an unlikely star to host a planet, according to this theory. There has not been enough time for a planet to grow through the slow accumulation of smaller debris. Complicating the story further is that TW Hydrae is only 55 percent as massive as our Sun.

“It’s so intriguing to see a system like this,” said John Debes of the Space Telescope Science Institute in Baltimore, Md. Debes leads a research team that identified the gap. “This is the lowest-mass star for which we’ve observed a gap so far out.”

An alternative planet-formation theory suggests that a piece of the disk becomes gravitationally unstable and collapses on itself. In this scenario, a planet could form more quickly, in just a few thousand years.

“If we can actually confirm that there’s a planet there, we can connect its characteristics to measurements of the gap properties,” Debes said. “That might add to planet formation theories as to how you can actually form a planet very far out.”

The TW Hydrae disk also lacks large dust grains in its outer regions. Observations from the Atacama Large Millimeter Array in Chile show dust grains roughly the size of a grain of sand are not present beyond about 5.5 billion miles from the star, just short of the gap.

“Typically, you need pebbles before you can have a planet. So, if there is a planet and there is no dust larger than a grain of sand farther out, that would be a huge challenge to traditional planet formation models,” Debes said.

The team used Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) to observe the star in near-infrared light. The researchers then compared the NICMOS images with archival Hubble data and optical and spectroscopic observations from Hubble’s Space Telescope Imaging Spectrograph (STIS). Debes said researchers see the gap at all wavelengths, which indicates it is a structural feature and not an illusion caused by the instruments or scattered light.

RADIO ASTRONOMERS USE PRECISION PULSAR POSITIONS TO BREAK DISTANCE RECORD

An international team of scientists led by astronomer Adam Deller (ASTRON) have used the Very Long Baseline Array (VLBA) to set a new distance accuracy record, pegging a pulsar called PSR J2222-0137 at 871.4 light-years from Earth. They did this by observing the object over a two-year period to detect its parallax, the slight shift in apparent position against background objects when viewed from opposite ends of Earth’s orbit around the Sun. With an uncertainty less than four light-years, this distance measurement is 30 percent more accurate than that of the previous-best pulsar distance.

The VLBA observations were even able to discern the orbital motion of the pulsar around its as-yet undetected companion object, despite this motion being no larger than a small coin observed at a tenth of the distance to the Moon. The results of the research have been published in The Astrophysical Journal

By showing that PSR J2222-0137 is 15% closer than previous estimates, this impressive achievement can advance our understanding of the system. With the distance to the pulsar pinned down, proposed highly sensitive visible-light observations should determine the nature of the undetected companion. If no source can be found, the companion must be a neutron star, while a white-dwarf companion will show up as a faint optical source.

The accuracy of the new measurement promises to help in the quest to detect the elusive gravitational waves predicted by general relativity. By monitoring an array of pulsars across the Milky Way galaxy, scientists hope to measure the distortions of space-time caused by the passage of gravitational waves. Knowing the distances to these pulsars extremely precisely can improve the sensitivity of the technique to detect individual sources of gravitational waves. The VLBA is operated by the National Radio Astronomy Observatory (NRAO).

NASA’S CHANDRA TURNS UP BLACK HOLE BONANZA IN GALAXY NEXT DOOR

Using data from NASA’s Chandra X-ray Observatory, astronomers have discovered an unprecedented bonanza of black holes in the Andromeda Galaxy, one of the nearest galaxies to the Milky Way.

Using more than 150 Chandra observations, spread over 13 years, researchers identified 26 black hole candidates, the largest number to date, in a galaxy outside our own. Many consider Andromeda to be a sister galaxy to the Milky Way. The two ultimately will collide, several billion years from now.

“While we are excited to find so many black holes in Andromeda, we think it’s just the tip of the iceberg,” said Robin Barnard of Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and lead author of a new paper describing these results. “Most black holes won’t have close companions and will be invisible to us.”

The black hole candidates belong to the stellar mass category, meaning they formed in the death throes of very massive stars and typically have masses five to 10 times that of our Sun. Astronomers can detect these otherwise invisible objects as material is pulled from a companion star and heated up to produce radiation before it disappears into the black hole.

The first step in identifying these black holes was to make sure they were stellar mass systems in the Andromeda Galaxy itself, rather than supermassive black holes at the hearts of more distant galaxies. To do this, the researchers used a new technique that draws on information about the brightness and variability of the X-ray sources in the Chandra data. In short, the stellar mass systems change much more quickly than the supermassive black holes.

To classify those Andromeda systems as black holes, astronomers observed that these X-ray sources had special characteristics: that is, they were brighter than a certain high level of X-rays and also had a particular X-ray color. Sources containing neutron stars, the dense cores of dead stars that would be the alternate explanation for these observations, do not show both of these features simultaneously. But sources containing black holes do.

The European Space Agency’s XMM-Newton X-ray observatory added crucial support for this work by providing X-ray spectra, the distribution of X-rays with energy, for some of the black hole candidates. The spectra are important information that helps determine the nature of these objects.

“By observing in snapshots covering more than a dozen years, we are able to build up a uniquely useful view of M31,” said co-author Michael Garcia, also of CfA. “The resulting very long exposure allows us to test if individual sources are black holes or neutron stars.”

The research group previously identified nine black hole candidates within the region covered by the Chandra data, and the present results increase the total to 35. Eight of these are associated with globular clusters, the ancient concentrations of stars distributed in a spherical pattern about the center of the galaxy. This also differentiates Andromeda from the Milky Way as astronomers have yet to find a similar black hole in one of the Milky Way’s globular clusters.

Seven of these black hole candidates are within 1,000 light-years of the Andromeda Galaxy’s center. That is more than the number of black hole candidates with similar properties located near the center of our own galaxy. This is not a surprise to astronomers because the bulge of stars in the middle of Andromeda is bigger, allowing more black holes to form.

“When it comes to finding black holes in the central region of a galaxy, it is indeed the case where bigger is better,” said co-author Stephen Murray of Johns Hopkins University and CfA. “In the case of Andromeda we have a bigger bulge and a bigger supermassive black hole than in the Milky Way, so we expect more smaller black holes are made there as well.”

This new work confirms predictions made earlier in the Chandra mission about the properties of X-ray sources near the center of M31. Earlier research by Rasmus Voss and Marat Gilfanov of the Max Planck Institute for Astrophysics in Garching, Germany, used Chandra to show there was an unusually large number of X-ray sources near the center of M31. They predicted most of these extra X-ray sources would contain black holes that had encountered and captured low mass stars. This new detection of seven black hole candidates close to the center of M31 gives strong support to these claims.

“We are particularly excited to see so many black hole candidates this close to the center, because we expected to see them and have been searching for years,” said Barnard.

THE FLARE STAR WX UMA BECOMES 15 TIMES BRIGHTER IN LESS THAN 3 MINUTES

Astrophysicists at the University of Santiago de Compostela (Spain) and the Byurakan Observatory (Armenia) have detected a star of low luminosity which within a matter of moments gave off a flare so strong that it became almost 15 times brighter. The star in question is the flare star WX UMa.

“We recorded a strong flare of the star WX UMa, which became almost 15 times brighter in a matter of 160 seconds,” explains to SINC the astrophysicist Vakhtang Tamazian, professor at the University of Santiago de Compostela. The finding has been published in the ‘Astrophysics’ journal.

This star is in the Ursa Major constellation, around 15.6 light-years from the Earth, and it forms part of a binary system. Its companion shines almost 100 times brighter, except at times such as that observed, in which the WX UMa gives off its flares. This can happen several times a year, but not as strongly as that which was recorded in this instance.

Dr. Tamazian and other researchers detected this exceptional brightness from the Byurakan Observatory in Armenia. “Furthermore, during this period of less than three minutes the star underwent an abrupt change from spectral type M to B; in other words, it went from a temperature of 2,800 kelvin (K) to six or seven times more than that.”

Based on their spectral absorption lines, stars are classified using letters. Type M stars have a surface temperature of between 2,000 and 3,700 K; type B between 10,000 and 33,000 K.

WX UMa belongs to the limited group of “flare stars,” a class of variable stars which exhibit increases in brightness of up to 100 factors or more within a matter of seconds or minutes. These increases are sudden and irregular, practically random, in fact. They then return to their normal state within tens of minutes.

Scientists do not know how this flaring arises, but they know how it develops: “For some reason a small focus of instability arises within the plasma of the star, which causes turbulence in its magnetic field,” explains Tamazian. “A magnetic reconnection then occurs, a conversion of energy from the magnetic field into kinetic energy, in order to recover the stability of the flow, much like what happens in an electric discharge.”

Next, kinetic energy in the plasma transforms into thermal energy in the upper layers of the atmosphere and the star’s corona. This significant rise in the temperature and brightness of the star enables astronomers to detect changes in the radiation spectrum.

“Photometric and spectroscopic monitoring of this kind of flare stars is very relevant because it provides us with information about the changing states and physical processes, which are in turn key to studying the formation and evolution of stars,” Tamazian explains.

Additionally, in cases of binary systems such as that which unites WX UMa with its companion, “observation of flares acquires a special importance, because we can investigate whether there is any relation between the frequency of flares and the position of the pair of stars on their orbit, a question which remains open.”

To carry out this study, in which flares in other binary systems (HU Del, CM Dra and VW Com) have also been analyzed, the SCORPIO camera of the Byurakan Astrophysical Observatory was used. This camera enables both the spectrum and the brightness of these objects to be detected.

Flare stars are intrinsically weak, and can therefore only be observed at relatively short distances in astronomic terms, specifically in the vicinity of the Sun, up to a distance of a few tens of light-years.