2013/11/05
Space Station Live: Nov. 4, 2013
NASA Kepler Results Usher in a New Era of Astronomy
Included in these findings is the discovery of 833 new candidate planets, which will be announced today by the Kepler team. Ten of these candidates are less than twice the size of Earth and orbit in their sun's habitable zone, which is defined as the range of distance from a star where the surface temperature of an orbiting planet may be suitable for liquid water.
At this conference two years ago, the Kepler team announced its first confirmed habitable zone planet, Kepler-22b. Since then, four more habitable zone candidates have been confirmed, including two in a single system.
New Kepler data analysis and research also show that most stars in our galaxy have at least one planet. This suggests that the majority of stars in the night sky may be home to planetary systems, perhaps some like our solar system.
"The impact of the Kepler mission results on exoplanet research and stellar astrophysics is illustrated by the attendance of nearly 400 scientists from 30 different countries at the Kepler Science Conference," said William Borucki, Kepler science principal investigator at Ames. "We gather to celebrate and expand our collective success at the opening of a new era of astronomy."
From the first three years of Kepler data, more than 3,500 potential worlds have emerged. Since the last update in January, the number of planet candidates identified by Kepler increased by 29 percent and now totals 3,538. Analysis led by Jason Rowe, research scientist at the SETI Institute in Mountain View, Calif., determined that the largest increase of 78 percent was found in the category of Earth-sized planets, based on observations conducted from May 2009 to March 2012. Rowe's findings support the observed trend that smaller planets are more common.
An independent statistical analysis of nearly all four years of Kepler data suggests that one in five stars like the sun is home to a planet up to twice the size of Earth, orbiting in a temperate environment. A research team led by Erik Petigura, doctoral candidate at University of California, Berkeley, used publicly accessible data from Kepler to derive this result.
Kepler data also fueled another field of astronomy dubbed asteroseismology -- the study of the interior of stars. Scientists examine sound waves generated by the boiling motion beneath the surface of the star. They probe the interior structure of a star just as geologists use seismic waves generated by earthquakes to probe the interior structure of Earth.
"Stars are the building blocks of the galaxy, driving its evolution and providing safe harbors for planets. To study the stars, one truly explores the galaxy and our place within it," said William Chaplin, professor for astrophysics at the University of Birmingham in the United Kingdom. "Kepler has revolutionized asteroseismology by giving us observations of unprecedented quality, duration and continuity for thousands of stars. These are data we could only have dreamt of a few years ago."
Kepler's mission is to determine what percentage of stars like the sun harbor small planets the approximate size and temperature of Earth. For four years, the space telescope simultaneously and continuously monitors the brightness of more than 150,000 stars, recording a measurement every 30 minutes. More than a year of the collected data remains to be fully reviewed and analyzed.
Ames is responsible for the Kepler mission concept, ground system development, mission operations, and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development.
Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.
The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate.
It’s Like a Party in the Atmosphere!
Ever attend a wild party with flashing lights and loud music that
snowballs into a dazzling moment worth remembering? That’s something
like how scientists describe the chain reactions in our atmosphere that
lead to lightning. In September, researchers began using the International Space Station
as a platform to study the mysterious cosmic catalyst and consequence
of lightning, which may actually have origins more explosive than you
might guess.
The Space Test Program-Houston 4-FireStation (STP-H4-FireStation) investigation, also simply known as FireStation, will orbit the Earth for a year attached to the outside of the space station. FireStation is sponsored by NASA and the National Science Foundation in partnership with the U.S. Department of Defense and its Space Test Program. This instrument collects data as it flies over thunderstorms, taking aim at the exciting energy exhibit to help scientists answer burning questions involving the relationship between lightning and gamma rays.
“Somewhere in the atmosphere momentarily there’s just an incredible amount of energy release and what happens in that region is something of a witch’s brew,” said Doug Rowland, principal investigator for FireStation at NASA's Goddard Space Flight Center in Greenbelt, Md. “You get antimatter created in the Earth’s atmosphere during this interaction, you get energetic neutrons that basically you never see in the quiet atmosphere, that you only associate with nuclear reactions, that are happening in our atmosphere whenever these things go off. That’s one of the first fundamental science reasons [to study this phenomenon]—it’s part of our planet; we don’t understand it; we want to understand it.”
During the “atmospheric party” of a thunderstorm, clouds charge as ice crystals rub together. This dance separates them by electrical charge and weight, leading to a sudden and dramatic release of lightning. While we know this is the source of the dazzling display, scientists still don’t fully understand what initiates the process. A prevailing theory is a chain reaction called a seeded avalanche breakdown, which is where an outside energy source sets off a few energetic-free electrons within the Earth’s electron field. “The idea is that you get a cosmic ray coming in that has a million electron volts of energy and it can serve to trigger another breakdown mechanism that generates gamma rays,” said Rowland.
Seen as terrestrial gamma ray flashes (TGFs), these events are short—on the line of milliseconds, like a lightning flash—bursts of gamma rays (ionizing radiation) from the Earth’s atmosphere. With a typical energy level of 1/40th of an electron volt, it is not intuitive to think of the planet as the origin of these quick flashes that have as much as 100 million electron volts. “I always thought this was a really weird idea,” said Rowland, “that your local weather, that your lightning depends on a cosmic ray that’s traveled for 150 thousand light years or a million light years from some exploding star that just set off your lightning stroke over your head.”
FireStation is capable of measuring these lightning and gamma ray flash events simultaneously to determine if TGFs are indeed generated by the electric fields during thunderstorms. The goal is to better understand the fundamental connection between the two natural phenomena. Researchers want to know what kinds of lighting produce gamma ray flashes and delve into the mechanisms of how this process takes place.
Putting FireStation on the space station allows for simultaneous readings and higher data collection than possible with the related CubeSat mission, called Firefly. Hitching a ride aboard station enables ground telemetry communications of 500 kilobits per second—faster than most mobile phones connect to the Internet—vs. the 300 bits per second possible with Firefly, which is a constraint similar to a slow modem from the 1980s. This means FireStation will be able to collect and transmit complete datasets for analysis. “On FireStation we get every single event, every single gamma ray that hits our detector, and we can sort them out on the ground using ground-based computers, so that’s a huge help,” said Rowland.
Without the specific instrument and the platform of the space station, this could have been a “chicken or the egg” type scenario. “We are measuring lightning flashes—which has been done before—and we are measuring gamma ray flashes—which has been done before—but we are doing it on the same platform, so that we can see for the same event the lighting and the gamma rays it produces,” said Rowland. “You can imagine a case where if you don’t know exactly where the events and the signals were traveling at different speeds, you might reverse the cause and effect. So having it in the same platform is new and very helpful.”
As the space station orbits the Earth and encounters a thunderstorm, FireStation collects data. This starts with the radio signals from a distance as the station approaches a storm that is still thousands of miles away. As the instrument gets closer to the storm, a gamma ray detector will capture evidence of TGFs. “We’ll start to pick up individual lightning flashes,” said Rowland, “and then maybe once in awhile we’ll see one of these TGF events lined up with a radio emission and an optical emission all close together within milliseconds of each other. We’ll say that’s a gamma ray flash event and study those.”
The FireStation instrument is made up of three components: a set of two radio wave antennas, a collection of nine photo detectors and a gamma ray detector. The two antennas—a rabbit ear antenna and a magnetic loop antenna—measure lightning by picking up the specific audio frequencies produced by the electromagnetic fields vibrating. This can sound something like bacon frying or similar to a whistle, depending on the type of lightning, which falls within a few kilohertz range. The gamma ray detector uses a special transparent crystal that illuminates when in contact with gamma rays. The photo detectors pick up the generated light signals as evidence of possible TGFs for researchers.
“We really want to be able to say that lightning happens 60 times a second all over the world and yet the gamma ray flashes are observed at a space of something like a few times an hour, if you globally integrate the known measurements and extrapolate the known measurement,” said Rowland. “So what is it about those lightning flashes that is unusual or special?”
With a bass system of thunder and a radiant show of lightning, an atmospheric party is the ultimate “see and be seen” event to study. While FireStation is a fundamental science mission, lightning research as a whole stands to help people on the ground in more ways than one. “There’s lots of interest in lightning research in general,” said Rowland. “If you can predict under what conditions lightning is more common or more frequent or more hazardous, you can better design your lighting protection systems and you can better design your power grid to handle lighting.”
The Space Test Program-Houston 4-FireStation (STP-H4-FireStation) investigation, also simply known as FireStation, will orbit the Earth for a year attached to the outside of the space station. FireStation is sponsored by NASA and the National Science Foundation in partnership with the U.S. Department of Defense and its Space Test Program. This instrument collects data as it flies over thunderstorms, taking aim at the exciting energy exhibit to help scientists answer burning questions involving the relationship between lightning and gamma rays.
“Somewhere in the atmosphere momentarily there’s just an incredible amount of energy release and what happens in that region is something of a witch’s brew,” said Doug Rowland, principal investigator for FireStation at NASA's Goddard Space Flight Center in Greenbelt, Md. “You get antimatter created in the Earth’s atmosphere during this interaction, you get energetic neutrons that basically you never see in the quiet atmosphere, that you only associate with nuclear reactions, that are happening in our atmosphere whenever these things go off. That’s one of the first fundamental science reasons [to study this phenomenon]—it’s part of our planet; we don’t understand it; we want to understand it.”
During the “atmospheric party” of a thunderstorm, clouds charge as ice crystals rub together. This dance separates them by electrical charge and weight, leading to a sudden and dramatic release of lightning. While we know this is the source of the dazzling display, scientists still don’t fully understand what initiates the process. A prevailing theory is a chain reaction called a seeded avalanche breakdown, which is where an outside energy source sets off a few energetic-free electrons within the Earth’s electron field. “The idea is that you get a cosmic ray coming in that has a million electron volts of energy and it can serve to trigger another breakdown mechanism that generates gamma rays,” said Rowland.
Seen as terrestrial gamma ray flashes (TGFs), these events are short—on the line of milliseconds, like a lightning flash—bursts of gamma rays (ionizing radiation) from the Earth’s atmosphere. With a typical energy level of 1/40th of an electron volt, it is not intuitive to think of the planet as the origin of these quick flashes that have as much as 100 million electron volts. “I always thought this was a really weird idea,” said Rowland, “that your local weather, that your lightning depends on a cosmic ray that’s traveled for 150 thousand light years or a million light years from some exploding star that just set off your lightning stroke over your head.”
FireStation is capable of measuring these lightning and gamma ray flash events simultaneously to determine if TGFs are indeed generated by the electric fields during thunderstorms. The goal is to better understand the fundamental connection between the two natural phenomena. Researchers want to know what kinds of lighting produce gamma ray flashes and delve into the mechanisms of how this process takes place.
Putting FireStation on the space station allows for simultaneous readings and higher data collection than possible with the related CubeSat mission, called Firefly. Hitching a ride aboard station enables ground telemetry communications of 500 kilobits per second—faster than most mobile phones connect to the Internet—vs. the 300 bits per second possible with Firefly, which is a constraint similar to a slow modem from the 1980s. This means FireStation will be able to collect and transmit complete datasets for analysis. “On FireStation we get every single event, every single gamma ray that hits our detector, and we can sort them out on the ground using ground-based computers, so that’s a huge help,” said Rowland.
Without the specific instrument and the platform of the space station, this could have been a “chicken or the egg” type scenario. “We are measuring lightning flashes—which has been done before—and we are measuring gamma ray flashes—which has been done before—but we are doing it on the same platform, so that we can see for the same event the lighting and the gamma rays it produces,” said Rowland. “You can imagine a case where if you don’t know exactly where the events and the signals were traveling at different speeds, you might reverse the cause and effect. So having it in the same platform is new and very helpful.”
As the space station orbits the Earth and encounters a thunderstorm, FireStation collects data. This starts with the radio signals from a distance as the station approaches a storm that is still thousands of miles away. As the instrument gets closer to the storm, a gamma ray detector will capture evidence of TGFs. “We’ll start to pick up individual lightning flashes,” said Rowland, “and then maybe once in awhile we’ll see one of these TGF events lined up with a radio emission and an optical emission all close together within milliseconds of each other. We’ll say that’s a gamma ray flash event and study those.”
The FireStation instrument is made up of three components: a set of two radio wave antennas, a collection of nine photo detectors and a gamma ray detector. The two antennas—a rabbit ear antenna and a magnetic loop antenna—measure lightning by picking up the specific audio frequencies produced by the electromagnetic fields vibrating. This can sound something like bacon frying or similar to a whistle, depending on the type of lightning, which falls within a few kilohertz range. The gamma ray detector uses a special transparent crystal that illuminates when in contact with gamma rays. The photo detectors pick up the generated light signals as evidence of possible TGFs for researchers.
“We really want to be able to say that lightning happens 60 times a second all over the world and yet the gamma ray flashes are observed at a space of something like a few times an hour, if you globally integrate the known measurements and extrapolate the known measurement,” said Rowland. “So what is it about those lightning flashes that is unusual or special?”
With a bass system of thunder and a radiant show of lightning, an atmospheric party is the ultimate “see and be seen” event to study. While FireStation is a fundamental science mission, lightning research as a whole stands to help people on the ground in more ways than one. “There’s lots of interest in lightning research in general,” said Rowland. “If you can predict under what conditions lightning is more common or more frequent or more hazardous, you can better design your lighting protection systems and you can better design your power grid to handle lighting.”
2013/11/01
Hubble's New Shot of Proxima Centauri, our Nearest Neighbor
Proxima Centauri lies in the constellation of Centaurus (The Centaur), just over four light-years from Earth. Although it looks bright through the eye of Hubble, as you might expect from the nearest star to the Solar System, Proxima Centauri is not visible to the naked eye. Its average luminosity is very low, and it is quite small compared to other stars, at only about an eighth of the mass of the sun.
However, on occasion, its brightness increases. Proxima is what is known as a flare star," meaning that convection processes within the star’s body make it prone to random and dramatic changes in brightness. The convection processes not only trigger brilliant bursts of starlight but, combined with other factors, mean that Proxima Centauri is in for a very long life. Astronomers predict that this star will remain middle-aged — or a "main sequence" star in astronomical terms — for another four trillion years, some 300 times the age of the current Universe.
These observations were taken using Hubble’s Wide Field and Planetary Camera 2 (WFPC2). Proxima Centauri is actually part of a triple star system — its two companions, Alpha Centauri A and B, lie out of frame.
Although by cosmic standards it is a close neighbor, Proxima Centauri remains a point-like object even using Hubble’s eagle-eyed vision, hinting at the vast scale of the Universe around us.
Comet Ison Roars Through Leo
At this time of this image, ISON was located in the constellation of Leo the Lion, some 132 million miles from Earth and heading in toward the sun at 87,900 miles per hour.
Galaxy Growth Examined Like Rings of a Tree
Galaxies outlive trees by billions of years, making their growth impossible to see. But like biologists, astronomers can read the rings in a galaxy's disk to unravel its past. Using data from NASA's Wide-field Infrared Survey Explorer (WISE) and Galaxy Evolution Explorer (GALEX), scientists have acquired more evidence for the "inside-out" theory of galaxy growth, showing that bursts of star formation in central regions were followed one to two billion years later by star birth in the outer fringes.
"Initially, a rapid star-forming period formed the mass at the center of these galaxies, followed later by a star-forming phase in the outer regions. Eventually, the galaxies stop making stars and become quiescent," said Sara Petty of Virginia Tech, Blacksburg, Va., lead author of a paper appearing in the October 2013 issue of the Astronomical Journal. "This later star-forming phase could have been caused by minor mergers with gas-rich neighbors, which provide the fuel for new stars."
The discovery may also solve a mystery of elderly galaxies. The galaxies in the study, known as "red and dead" for their red color and lack of new star births, have a surprising amount of ultraviolet light emanating from the outer regions. Often, ultraviolet light is generated by hot, young stars, but these galaxies were considered too old to host such a young population.
The solution to the puzzle is likely hot, old stars. Petty and colleagues used a new multi-wavelength approach to show that the unexplained ultraviolet light appears to be coming from a late phase in the lives of older stars, when they blow off their outer layers and heat up.
GALEX and WISE turned out to be the ideal duo for the study. GALEX was sensitive to the ultraviolet light, whereas WISE sees the infrared light coming from older stars. GALEX is no longer operating, but WISE was recently reactivated to hunt asteroids, a project called NEOWISE (see http://www.jpl.nasa.gov/news/news.php?release=2013-257 ). Both telescopes have large fields of view, allowing them to easily capture images of entire galaxies.
"The synergy between GALEX and WISE produces a very sensitive measurement of where the hot, older stars reside in these red-and-dead galaxies," said Don Neill, co-author of the paper from the California Institute of Technology, Pasadena. "This allows us to map the progress of star formation within each galaxy."
Ned Wright of UCLA, a co-author of the study and the principal investigator of WISE before it was reactivated, compares the multi-wavelength range of the two telescopes to musical notes, "WISE itself covers the equivalent of a three-octave range, while WISE and GALEX together cover a seven-octave range."
The technical paper for this study is online at http://arxiv.org/abs/1307.6282 .
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages and operates the recently activated NEOWISE mission for NASA's Science Mission Directorate. The WISE mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise .
Caltech led the Galaxy Evolution Explorer mission and was responsible for science operations and data analysis. JPL managed the mission and built the science instrument. The mission was developed under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. Researchers sponsored by Yonsei University in South Korea and the Centre National d'Etudes Spatiales (CNES) in France collaborated on this mission. Graphics and additional information about the Galaxy Evolution Explorer are online at http://www.nasa.gov/galex and http://www.galex.caltech.edu.
Soyuz Move Sets Stage for Arrival of New Crew
Commander Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano undocked their Soyuz TMA-09M spacecraft from the Rassvet module on the Earth-facing side of the station at 4:33 a.m. EDT Friday. After backing the vehicle a safe distance away, Soyuz Commander Yurchikhin rotated the Soyuz and began the flyaround to the rear of the station. Carefully aligning the spacecraft with the docking port on the aft end of the Zvezda service module, which was vacated by the European Space Agency’s fourth Automated Transfer Vehicle (ATV) on Monday, Yurchikhin guided the spacecraft in for its docking at 4:54 a.m.
› Watch video of Soyuz relocation
Coincidentally, Yurchikhin was at the helm for the last Soyuz relocation at the station in June 2010 when he piloted the Expedition 24 crew’s Soyuz TMA-19 vehicle from Zvezda to the then newly installed Rassvet module.
Friday’s Soyuz move sets the stage for the launch and arrival of a trio of new station crew members -- NASA astronaut Rick Mastracchio, Japan Aerospace Exploration Agency astronaut Koichi Wakata and Soyuz Commander Mikhail Tyurin of the Russian Federal Space Agency – who will dock their Soyuz TMA-11M spacecraft to Rassvet on Nov. 7 about six hours after their launch from the Baikonur Cosmodrome in Kazakhstan.
› View NASA Television coverage schedule
The arrival of Mastracchio, Wakata and Tyurin will mark the first time since October 2009 that nine people have served together aboard the station without the presence of a space shuttle.
Also arriving to the station aboard the Soyuz TMA-11M will be the Olympic torch, which is making the longest leg of its relay leading up to the 2014 Winter Olympics in Sochi, Russian. Flight Engineers Oleg Kotov and Sergey Ryazanskiy will take the Olympic torch outside the station during a symbolic spacewalk on Nov. 9.
The torch will return to Earth along with Yurchikhin, Nyberg and Parmitano on Nov. 10 when they board their Soyuz for the journey home after more than five months in space.
The final departure of Yurchikhin, Nyberg and Parmitano will free the Zvezda port for the docking of a new Progress resupply vehicle in late November. Program managers prefer to have a Progress or ATV cargo ship docked at Zvezda so it can help reboost the station and adjust its attitude.
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