NASA's Fermi Makes First Gamma-ray Study of a Gravitational Lens

An international team of astronomers, using NASA's Fermi observatory, has made the first-ever gamma-ray measurements of a gravitational lens, a kind of natural telescope formed when a rare cosmic alignment allows the gravity of a massive object to bend and amplify light from a more distant source.
This accomplishment opens new avenues for research, including a novel way to probe emission regions near supermassive black holes. It may even be possible to find other gravitational lenses with data from the Fermi Gamma-ray Space Telescope.
We began thinking about the possibility of making this observation a couple of years after Fermi launched, and all of the pieces finally came together in late 2012," said Teddy Cheung, lead scientist for the finding and an astrophysicist at the Naval Research Laboratory in Washington.
In September 2012, Fermi's Large Area Telescope (LAT) detected a series of bright gamma-ray flares from a source known as B0218+357, located 4.35 billion light-years from Earth in the direction of a constellation called Triangulum. These powerful flares, in a known gravitational lens system, provided the key to making the lens measurement.
Astronomers classify B0218+357 as a blazar -- a type of active galaxy noted for its intense emissions and unpredictable behavior. At the blazar's heart is a supersized black hole with a mass millions to billions of times that of the sun. As matter spirals toward the black hole, some of it blasts outward as jets of particles traveling near the speed of light in opposite directions.
The extreme brightness and variability of blazars result from a chance orientation that brings one jet almost directly in line with Earth. Astronomers effectively look down the barrel of the jet, which greatly enhances its apparent emission.

Long before light from B0218+357 reaches us, it passes directly through a face-on spiral galaxy -- one very much like our own -- about 4 billion light-years away.
The galaxy's gravity bends the light into different paths, so astronomers see the background blazar as dual images. With just a third of an arcsecond (less than 0.0001 degree) between them, the B0218+357 images hold the record for the smallest separation of any lensed system known.
While radio and optical telescopes can resolve and monitor the individual blazar images, Fermi's LAT cannot. Instead, the Fermi team exploited a "delayed playback" effect.
"One light path is slightly longer than the other, so when we detect flares in one image we can try to catch them days later when they replay in the other image," said team member Jeff Scargle, an astrophysicist at NASA's Ames Research Center in Moffett Field, Calif.
In September 2012, when the blazar's flaring activity made it the brightest gamma-ray source outside of our own galaxy, Cheung realized it was a golden opportunity. He was granted a week of LAT target-of-opportunity observing time, from Sept. 24 to Oct. 1, to hunt for delayed flares.
At the American Astronomical Society meeting in National Harbor, Md., Cheung said the team had identified three episodes of flares showing playback delays of 11.46 days, with the strongest evidence found in a sequence of flares captured during the week-long LAT observations.
Intriguingly, the gamma-ray delay is about a day longer than radio observations report for this system. And while the flares and their playback show similar gamma-ray brightness, in radio wavelengths one blazar image is about four times brighter than the other.
Astronomers don't think the gamma rays arise from the same regions as the radio waves, so these emissions likely take slightly different paths, with correspondingly different delays and amplifications, as they travel through the lens.
"Over the course of a day, one of these flares can brighten the blazar by 10 times in gamma rays but only 10 percent in visible light and radio, which tells us that the region emitting gamma rays is very small compared to those emitting at lower energies," said team member Stefan Larsson, an astrophysicist at Stockholm University in Sweden.
As a result, the gravity of small concentrations of matter in the lensing galaxy may deflect and amplify gamma rays more significantly than lower-energy light. Disentangling these so-called microlensing effects poses a challenge to taking further advantage of high-energy lens observations.
The scientists say that comparing radio and gamma-ray observations of additional lens systems could help provide new insights into the workings of powerful black-hole jets and establish new constraints on important cosmological quantities like the Hubble constant, which describes the universe's rate of expansion.
The most exciting result, the team said, would be the LAT's detection of a playback delay in a flaring gamma-ray source not yet identified as a gravitational lens in other wavelengths.
A paper describing the research will appear in a future edition of The Astrophysical Journal Letters.
NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership. Fermi is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. It was developed in collaboration with the U.S. Department of Energy, with contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

New Science Bound for Station on Orbital’s Cygnus

Delivering ants to space, sloshy fluids for robotic satellites, a study on antibiotic drug resistance and other small satellites to the International Space Station can be a tough job, and now Orbital Sciences Corporation of Dulles, Va., can help carry the load. In its first commercial resupply journey after completion of NASA’s Commercial Orbital Transportation Services program, the Orbital-1 mission will deliver some very interesting new scientific investigations to the space station.
Orbital’s Antares rocket is planned to launch Jan. 8 from Wallops Flight Facility in eastern Virginia. Antares is scheduled to deliver the Cygnus spacecraft full of new research investigations, supplies and other space station hardware to the space station on Jan. 12.
One of the new research investigations traveling to the orbiting laboratory is the Commercial Generic Bioprocessing Apparatus Science Insert - 06: Ants in Space (CSI-06). Students in grades K-12 will observe videos of these “ant-ronauts” recorded by cameras on the space station. The students will also conduct their own ant interaction investigations in their classrooms as part of a related curriculum. Educational investigations such as Ants in Space are designed to motivate budding scientists in primary and secondary school to pursue their interest in the science, technology, engineering and mathematics fields.
The Ants in Space study examines the behavior of ants by comparing groups living on Earth to those in space. The idea is that ant interactions are dependent upon the number of ants in an area. Measuring these interactions may be important in determining behavior of ants in groups. This insight may add to existing knowledge of swarm intelligence, or how the complex behavior of a group is influenced by the actions of individuals. Developing a better understanding of swarm intelligence may lead to more refined mathematical procedures for solving complex problems, like routing trucks, scheduling airlines or telecommunications efficiency.
A second investigation launching with the Orbital-1 mission is the SPHERES-Slosh study. SPHERES-Slosh will use the existing space station facility of free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES). The goal is to look at how liquids slosh around inside containers in microgravity, showing how applied external forces impact the contents of those containers. The experiments simulate how rocket fuels move around inside their tanks in response to motor thrusts used to push a rocket through space. The study of the physics of liquid motion in microgravity is important because Earth’s most powerful rockets use liquid fuels to take satellites and other spacecraft into orbit. Having a deeper understanding of rocket propellants may lower the cost of industry and taxpayer-funded satellite launches by improving fuel efficiency.
A third investigation aboard the Cygnus spacecraft is a study of drug-resistant bacteria. Drug-resistant bacteria are of increasing concern to public health. As bacteria grow more resistant to antibiotics, there are less effective pharmaceutical treatment options for people with bacterial infections. Researchers for the Antibiotic Effectiveness in Space (AES-1) investigation aboard the space station look to determine gene expression patterns and changes using E. coli. This research builds upon previous space station investigations into drug-resistant bacteria, such as the National Laboratory Pathfinder Vaccine  Methicillin-resistant Staphylococcus aureus (NLP-Vaccine-MRSA) study of what is commonly referred to as staph infection.
The findings from AES-1 may help improve antibiotic development on Earth. Improving the efficacy of antibiotics and reducing their resistance to bacteria is a priority for health care professionals.
Small, relatively inexpensive satellites, collectively referred to as CubeSats, will provide a variety of technology demonstrations using the NanoRacks Smallsat Deployment Program to launch the satellites from the station’s Japanese Experiment Module (JEM) airlock. The NanoRacks CubeSats are deployed using the JEM Small Satellite Orbital Deployer (J-SSOD). View the illustrated simulation to see how these small satellites are deployed into space.
Using crowdsourcing methods for funding, the NanoRacks-ArduSat-2 investigation will test advanced electronics and hardware in the space environment with only minimal adaptation. Built and operated by NanoSatisfi of San Francisco, sensors on the NanoRacks-ArduSat-2 are set to determine potential commercial applications for CubeSat data collection and commercial off-the-shelf electronics. Testing these sensors through this mini-satellite format may contribute to technological information that helps lower the cost of applications that use low-Earth observation techniques.
Another small satellite investigation, the NanoRacks-Planet Labs–Dove Flock-1, will use a fleet of 28 CubeSats -- individually known as the Dove satellites -- to capture imagery of Earth for use in humanitarian and environmental applications. Built and operated by Planet Labs Inc. of San Francisco, imagery from these CubeSats will help pinpoint areas for disaster relief and improving growth of agricultural products in developing countries around the globe. In addition, information from the Dove CubeSats will focus on environmental protection measures, such as monitoring deforestation and changes to polar ice caps. The data collected by Planet Labs' CubeSats will be freely available for anyone to use.
A third example of some of the CubeSats launching with the Orbital-1 mission is the NanoRacks-SkyCube, developed by Southern Stars Group LLC of San Francisco. NanoRacks-SkyCube will provide an educational demonstration of the capabilities of CubeSats. To get the attention of the public, NanoRacks-Skycube will tweet from space via Twitter, capture imagery in orbit and use a balloon during its de-orbit and reentry into Earth’s atmosphere.
These are only a few of the many investigations headed to the space station this month. Students will closely observe ant behavior, fluids will slosh about in contained spaces, drug-resistant bacteria will be scrutinized and CubeSats will test their capabilities in orbit after being deployed from the space station. For 15 years, investigations have been underway every day aboard the orbiting outpost. This Orbital Sciences launch will bring more research to ensure that science continues aboard the space station.

Space Station Live: Orion Update From Astronaut Lee Morin

Astronaut Lee Morin, the head of the Rapid Prototyping Lab, talks with NASA Public Affairs Officer Amiko Kauderer about the latest development milestones for the Orion MPCV, including recent ascent and abort sims, in advance of EFT-1 in 2014.

Decade-Old Rover Adventure Continues on Mars and Earth

Eighth graders didn't have Facebook or Twitter to share news back then, in January 2004. Bekah Sosland, 14 at the time, learned about a NASA rover landing on Mars when the bouncing-ball video on the next morning's Channel One news in her Fredericksburg, Texas, classroom caught her eye.
"I wasn't particularly interested in space at the time," she recalled last week inside the spacecraft operations facility where she now works at NASA's Jet Propulsion Laboratory in Pasadena, Calif.  "I remember I was talking with friends, and out of the corner of my eye I noticed this thing bouncing and rolling on a red surface. I watched as it stopped and opened up, and it had this rover inside."
That animation portrayed how NASA landed the Mars rovers Spirit and Opportunity three weeks apart, using airbags to cushion the impact at the start of the missions, planned to last for three months. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, PST) and worked for six years. Opportunity landed on Jan. 25, UT (Jan. 24, PST) and is still exploring, with Sosland now on the team planning what it does each day.

"I watched that news and said, 'This is amazing: a rover on another planet!' Gears started turning in my head that day about engineering and space -- thinking about a career. It was definitely a milestone in my life and something I'll always remember."
On her path to that career, high-school teacher Brett Williams in Fredericksburg inspired her to build real rockets, and she completed a 2013 engineering degree from the University of Texas, Austin. But nobody in 2004 was predicting that either Spirit or Opportunity might still be roving Mars in summer 2013, which is when Sosland joined JPL.
"I certainly never thought I'd have an opportunity to work on Opportunity," she said. "That only became possible because this mission has been going so incredibly long. The reason Opportunity has worked so long is the people who built it and operate it. I'm loving that I can be a part of this team now."
Most of the engineers who operated Spirit and Opportunity during the three-month prime missions in 2004 have switched to other projects, including later Mars spacecraft. Sosland is among several on Opportunity's team today who were in school a decade ago.
Unlike her, Mike Seibert in late 2003 was eagerly tracking the run-up to the rover landings, while he was an engineering undergraduate at the University of Colorado. He had even ordered cardboard 3-D glasses in anticipation of images from stereo cameras on Spirit and Opportunity.
"I was living in my fraternity's house in Boulder that January. People thought I was weird, wearing 3-D glasses and looking at those pictures from Mars," said Seibert.
Less than two years later, he was working on the rover team at JPL. He has, since then, served as a mission manager and in other roles for both Spirit and Opportunity and participated in many key moments of the extended missions.
The dramatic landings and overland expeditions of Spirit and Opportunity have also inspired countless students who have not gained a chance to work on the rover team, but have participated in the adventure online by exploring images from the rovers or other activities.
What an adventure it's been. Though Spirit and Opportunity were built as nearly identical twins, and both succeeded in the main goal of finding evidence for ancient watery environments on Mars, their stories diverged early.
Spirit was sent to a crater where the basin's shape and apparent inflow channels seen from orbit suggested a lake once existed. Opportunity's landing area, almost exactly halfway around the planet, was selected mainly on the basis of a water-clue mineral detected from orbit, rather than landform shapes. Spirit's destination did not pan out initially. The crater may have held a lake, but if there are any lakebed sediments, they are thoroughly buried under later volcanic deposits. Opportunity, the luckier twin, landed a stone's throw from an exposure of layered rock that within weeks yielded compositional and textural evidence of a water-rich ancient environment.
Within the initial three-month missions and without expectation of surviving a full year, each rover set out cross-country toward other destinations: hills on the horizon for Spirit and craters exposing deeper layers for Opportunity. Spirit drove a total of 4.8 miles (7.7 kilometers), some of that with one of its six wheels not rotating. Loss of use of a second wheel while the rover was in a sand trap contributed to the 2010 end of that mission. Opportunity has driven 24 miles (38.7 kilometers) and is still going strong.
One key to Spirit and Opportunity working for years, instead of a few months, has been winds that occasionally remove some of the dust accumulating on solar panels that generate the rovers' electricity. Also, the ground crew became adept at managing each rover's power consumption and taking advantage of slopes for favorably tilting the rovers toward the sun during Martian winters.
"Ultimately, it's not only how long the rovers work or how far they drive that's most important, but how much exploration and scientific discovery these missions have accomplished," said JPL's John Callas, project manager for NASA's Mars Exploration Rover Project, who has worked on the Spirit and Opportunity missions for more than 13 years.
By driving to outcrops miles from their landing sites, both rovers reached evidence about multiple episodes of Martian history, "traveling across time as well as across Martian terrain," he said. Opportunity is currently exploring outcrops on the rim of Endeavour Crater, which is 14 miles (22 kilometers) in diameter.
"Opportunity is still in excellent health for a vehicle of its age," Callas said. "The biggest science may still be ahead of us, even after 10 years of exploration."
The science achievements have already provided major advances in understanding of Mars.
The rovers' principal investigator, Steve Squyres of Cornell University, Ithaca, N.Y., described some of the key findings, starting with what Spirit found after driving from the crater floor where it landed into hills to the east:
"In the Columbia Hills, we discovered compelling evidence of an ancient Mars that was a hot, wet, violent place, with volcanic explosions, hydrothermal activity, steam vents -- nothing like Mars today.
"At Opportunity's landing site, we found evidence of an early Mars that had acidic groundwater that sometimes reached the surface and evaporated away, leaving salts behind. It was an environment with liquid water, but very different from the environment that Spirit told us about.
"When Opportunity got to the rim of Endeavour Crater, we began a whole new mission.  We found gypsum veins and a rich concentration of clay minerals. The clay minerals tell us about water chemistry that was neutral, instead of acidic -- more favorable for microbial life, if any ever began on Mars."
"Because of the rovers' longevity, we essentially got four different landing sites for the price of two."
The evidence the rovers glean from rocks at these sites may not be the only huge benefit of the adventures, though.  Bekah Sosland and Mike Seibert may be examples of something even greater.
Squyres said, "I'm incredibly proud of the science we've done on this mission, but in the end, perhaps our most important legacy will turn out to be the young people who have seen what we've done and made career choices based on that. If an outcome of our mission is to help inspire a new generation of explorers to do even better than we did, that will be the greatest thing we could have accomplished."
The Mars Exploration Rover Project is one strong element in a robust program of NASA's ongoing and future Mars missions preparing for human missions there by the 2030s.
The Mars Odyssey and Mars Reconnaissance Orbiter missions have been studying the Red Planet since arriving there in 2001 and 2006, respectively. NASA's next-generation Mars rover, Curiosity, is examining an area that once offered conditions favorable for microbial life. NASA launched the Mars Atmosphere and Volatile Evolution, or MAVEN, mission two months ago, to begin orbiting in September 2014. The agency plans to launch a mission to Mars in 2016 called Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, to learn about the deep interior of Mars. A Curiosity-size rover planned for launch in 2020 has the task to check for evidence of past life on Mars.

Space Station Live: Science for 2014

International Space Station Chief Scientist Jule Robinson discusses some of the technology and research activity on tap for the orbital laboratory in 2014.

Two Solar Flares Say Goodbye 2013 and Welcome 2014

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he sun ushered out 2013 and welcomed 2014 with two mid-level flares on Dec. 31, 2013 and Jan. 1, 2014. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. This disrupts the radio signals for as long as the flare is ongoing, anywhere from minutes to hours.
To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.
The first flare (below) was categorized as an M6.4 and it peaked at 4:58 p.m EST on Dec. 31. The second (above) was categorized as an M9.9 and peaked at 1:52 p.m. EST on Jan. 1. Both flares emerged from the same active region on the sun, AR1936.
Imagery of the flares was captured by NASA's Solar Dynamics Observatory, which keeps a constant watch on the sun, collecting new data every 12 seconds.
Updates will be provided as needed.

More BARREL Balloons Take to the Skies

The second year of an unprecedented balloon campaign in Antarctica has just begun. The NASA-funded mission – called the Balloon Array for Radiation belt Relativistic Electron Losses, or BARREL – is led by Dartmouth College in Hanover, N.H. The mission is unique, as it relies not on one gigantic balloon, but on many smaller ones, 20 in total.
BARREL's job is to help unravel the mysterious radiation belts, two gigantic donuts of particles that surround Earth. The mission works in conjunction with NASA’s Van Allen Probes, two spacecraft currently orbiting around Earth to study the belts.
"This year the Van Allen Probes and the BARREL balloons will be exploring what happens at dusk," said Robyn Millan, principal investigator for BARREL at Dartmouth. "Balloon campaigns in the Antarctic region have long seen these bursts of particles precipitating down toward Earth at dusk. This year, the spacecraft and the balloons will have coordinated measurements to determine what's happening up in the belts during these events."
Millan and her team traveled to Antarctica in mid-December 2013, and they launched their first balloon on Dec. 27, 2013. They will launch a single balloon on any given day, which will float leisurely around the South Pole for up to a week or two afterwards. Instruments aboard the balloon will send back data on the magnetic systems it floats through, as well as the kinds of particles it observes. By coordinating with the Van Allen Probes data, orbiting high above, the team hopes to determine what's happening in the belts that correlates with the precipitation bursts near Earth. Such information will ultimately help scientists understand how particles get ejected from the belts.

 

The spacecraft will be taking measurements in the right place to observe the radiation belt environment during these precipitation events," said Millan. "We should be able to tell what is causing these events, and that is really one of the main goals of BARREL."

In addition to Dartmouth, the BARREL mission is supported by scientists from University of California-Berkeley, the University of Washington and University of California-Santa Cruz. Field operations are being conducted at the British research station Halley VI and the South African research station, SANAE IV. In addition to NASA and National Science Foundation support, the campaigns are supported by the National Environmental Research Council in the United Kingdom and the South African National Space Agency (SANSA).