When a rather large M 3.6 class flare occurred near the edge of the Sun on Feb. 24, 2011, it blew out a gorgeous, waving mass of erupting plasma that swirled and twisted for 90 minutes. NASA’s Solar Dynamics Observatory captured the event in extreme ultraviolet light. Because SDO images are high definition, the team was able to zoom in on the flare and still see exquisite details. And using a cadence of a frame taken every 24 seconds, the sense of motion is, by all appearances, seamless.
They nicknamed it the "Little Balloon That Could." Launched in December of 2010 from McMurdo Station in Antarctica, the research balloon was a test run and it bobbed lower every day like it had some kind of leak. But every day for five days it rose back up in the sky to some 112,000 feet in the air.
Down on Earth, physicist Robyn Millan was cheering it on, hoping the test launch would bode well for the success of her grand idea: launches in 2013 and 2014 of 20 such balloons to float in the circular wind patterns above the South Pole. Each balloon will help track electrons from space that get swept up in Earth's magnetic field and slide down into our atmosphere. Such electrons are an integral part of the turbulent magnetic space weather system that extends from the sun to Earth.
A professor at Dartmouth College, Millan is the principal investigator for a project called BARREL, or Balloon Array for RBSP Relativistic Electron Losses. Millan's proposal will work hand in hand with NASA's Radiation Belt Space Probes (RBSP) mission, two NASA spacecraft due to launch in 2012 to study a mysterious part of Earth's magnetic environs called the Van Allen radiation belts. The radiation belts are made up of two regions, each one a gigantic donut of protons and electrons that surrounds Earth.
"We're both looking at the loss of particles from the radiation belts," says Millan. "RBSP sits in space near the equatorial plane and looks at the particles along magnetic field lines there. These particles come into our atmosphere – following magnetic field lines to their base at the Poles – and produce X-rays. BARREL measures those X-rays. Together we can combine measurements of the same set of particles."
Figuring out what causes this rain of electrons will do more than simply improve understanding of the physics behind what drives such high-energy particles. The charged particles within the radiation belts can damage sensitive electronics on spacecraft like those used for global positioning systems and communications, and can injure humans in space. (The electrons don't make it all the way to Earth, so pose no danger to those of us on the ground.) Experiments like BARREL and RBSP help us understand the processes and mitigate those risks.
Millan began working on balloons during her graduate work at University of California, Berkeley, where she studied physics. She worked on a balloon called MAXIS that focused on electron precipitation from the magnetosphere into the ionosphere. "Then," she says, "We got this idea. They launch these huge payloads in Antarctica, but before that they send up smaller test balloons to make sure conditions are right for the big launch. And we thought – what if you could put instruments on those? So we took our payload, and miniaturized it."
She and her team, which includes scientists and students at UC Berkeley, UC Santa Cruz, and University of Washington, set about making payloads that weigh only 50 pounds for balloons that are some 90 feet in diameter. That still sounds fairly big unless you know that the typical balloons launched in Antarctica are the size of a football field and carry payloads of some 3,000 pounds. The team received funding from the National Science Foundation to fly a total of six small balloons in 2005, and shortly thereafter she learned that NASA had put out a call for experiments to support RBSP.
David Sibeck, the project scientist for RBSP at Goddard Space Flight Center in Greenbelt, Md., recalls that Millan's project proposal was well-tailored to RBSP's goals. "One of RBSP's main challenges will be to differentiate between the hordes of theories that try to explain why the belts wax and wane over time," Sibeck says. "The RBSP spacecraft will be equipped to distinguish between different options, but Millan's balloons have an advantage in one specific area: they can measure particles that break out of the belts and make it all the way to Earth's atmosphere."
The first test of BARREL -- funded by NASA and also supported by NSF's Office of Polar Programs that supports logistics of all research in Antarctica -- began in December of 2008. The final one began this past winter, when Millan left New Hampshire for Antarctica on Nov. 15. She arrived in McMurdo Station – after a transfer in Christ Church, New Zealand and a day lost due to crossing the date line – on Nov. 19. This flight needed to test travel and ease of launch capabilities as much as anything else, so Millan's team had shipped all the balloons ready to fly. Once in Antarctica, she and her colleague, Brett Anderson, a Dartmouth graduate student, got to work unpacking.
"It was great," she says. "We just had to pull them out of the box and turn them on. We mounted their solar panels and with just two people we were able to get things ready really fast, which isn't always the easiest thing to do when in Antarctica."
One reason to do such electron research at the Poles is that Earth's magnetic field lines touch down there. But equally important for this campaign are the slowly circling wind patterns that set up each summer. The BARREL project will release another balloon every 1-2 days and each should fall into line, consistently buoyed by the winds along the same circular path.
This past December – which is, of course, the summer in Antarctica – it took longer than normal for those winds, known as circumpolar winds, to set up. So when the first balloon was launched – a process spearheaded by the Columbia Scientific Balloon Facility -- it floated straight North towards Tasmania. This was the balloon that came to be known as The Little Balloon That Could, says Millan: "Perhaps it had a very small hole, but it didn't quite make it as high as it was supposed to – some 120,000 feet. It only ever got to 112,000 feet, but it maintained that height doggedly and even sent back some interesting data as it flew through an X-ray aurora.” A second balloon did hit the right wind current, successfully transmitting data. (The second balloon did, however, have to be cut down a little early due to an overheated battery.)
So now the BARREL team will begin work on preparing the real show – two campaigns of 20 balloons each that will be launched during the 2012 to 2014 time frame.
"Her balloons will work in conjunction with RBSP," says Sibeck. "She can let us know if they're seeing particles and RBSP can look for the events that might be scattering them out of the radiation belts down to Earth." In addition, since each balloon is meant to stay aloft for 10 days, they will cover a huge area in the sky. When RBSP spots an interesting phenomenon, BARREL can give feedback over a large area as to where the particles went. The team will be able to see how big that region is and measure the total amount of particles that get kicked out of the belts – and thus determine how big of an effect different phenomena have. "That's something we would have more trouble doing with the spacecraft," says Sibeck.
Once each balloon is launched it moves slowly by floating in the wind. Those on the ground cannot control it, other than the single command to terminate the mission. A small explosive detonates and cuts the cable to the payload, which then floats down to the ground on a parachute. This was the fate of the two test balloons in December 2010, though they were particularly sorry to cut down the Little Balloon That Could. "We really wanted to see how far it would go," says Millan. "But it was so far north that we were getting close to Australian air space and we had to cut it down."
So the team declared the test a success, packed up their gear and began the long trip home to New Hampshire to oversee the building of 45 more payloads.
Mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., have begun receiving the first of 72 anticipated images of comet Tempel 1 taken by NASA's Stardust spacecraft.
The first six, most distant approach images are available at http://www.nasa.gov/stardust and http://www.jpl.nasa.gov. Additional images, including those from closest approach, are being downlinked in chronological order and will be available later in the day.
A news conference will be held at 12:30 p.m. PST (3:30 p.m. EST) to allow scientists more time to analyze the data and images.
Stardust-NExT is a low-cost mission that expands on the investigation of comet Tempel 1 initiated by NASA's Deep Impact spacecraft. JPL, a division of the California Institute of Technology in Pasadena, manages Stardust-NExT for NASA's Science Mission Directorate, Washington, D.C. Joe Veverka of Cornell University, Ithaca, N.Y., is the mission's principal investigator. Lockheed Martin Space Systems, Denver, built the spacecraft and manages day-to-day mission operations.
Stars at all stages of development, from dusty little tots to young adults, are on display in a new image from NASA's Spitzer Space Telescope.
This cosmic community is called the North American nebula. In visible light, the region resembles the North American continent, with the most striking resemblance being the Gulf of Mexico. But in Spitzer's infrared view, the continent disappears. Instead, a swirling landscape of dust and young stars comes into view.
"One of the things that makes me so excited about this image is how different it is from the visible image, and how much more we can see in the infrared than in the visible," said Luisa Rebull of NASA's Spitzer Science Center at the California Institute of Technology, Pasadena, Calif. Rebull is lead author of a paper about the observations, accepted for publication in the Astrophysical Journal Supplement Series. "The Spitzer image reveals a wealth of detail about the dust and the young stars here."
Rebull and her team have identified more than 2,000 new, candidate young stars in the region. There were only about 200 known before. Because young stars grow up surrounded by blankets of dust, they are hidden in visible-light images. Spitzer's infrared detectors pick up the glow of the dusty, buried stars.
A star is born inside a collapsing ball of gas and dust. As the material collapses inward, it flattens out into a disk that spins around together with the forming star like a spinning top. Jets of gas shoot perpendicularly away from the disk, above and below it. As the star ages, planets are thought to form out of the disk -- material clumps together, ultimately growing into mature planets. Eventually, most of the dust dissipates, aside from a tenuous ring similar to the one in our solar system, referred to as Zodiacal dust.
The new Spitzer image reveals all the stages of a star's young life, from the early years when it is swaddled in dust to early adulthood, when it has become a young parent to a family of developing planets. Sprightly "toddler" stars with jets can also be identified in Spitzer's view.
"This is a really busy area to image, with stars everywhere, from the North American complex itself, as well as in front of and behind the region," said Rebull. "We refer to the stars that are not associated with the region as contamination. With Spitzer, we can easily sort this contamination out and clearly distinguish between the young stars in the complex and the older ones that are unrelated."
an nebula still has a mystery surrounding it, involving its power source. Nobody has been able to identify the group of massive stars that is thought to be dominating the nebula. The Spitzer image, like images from other telescopes, hints that the missing stars are lurking behind the Gulf of Mexico portion of the nebula. This is evident from the illumination pattern of the nebula, especially when viewed with the detector on Spitzer that picks up 24-micron infrared light. That light appears to be coming from behind the Gulf of Mexico's dark tangle of clouds, in the same way that sunlight creeps out from behind a rain cloud.
The nebula's distance from Earth is also a mystery. Current estimates put it at about 1,800 light-years from Earth. Spitzer will refine this number by finding more stellar members of the North American complex.
The Spitzer observations were made before it ran out of the liquid coolant needed to chill its longer-wavelength instruments. Currently, Spitzer's two shortest-wavelength channels (3.6 and 4.5 microns) are still working. The composite image shows light from both the infrared array camera and multiband imaging processor. Infrared light with a wavelength of 3.6 microns is color-coded blue; 8.0-micron light is green; and 24-micron light is red.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. For more information about Spitzer.
NASA's Stardust spacecraft marked its 12th anniversary in space on Monday, Feb. 7, with a rocket burn to further refine its path toward a Feb. 14 date with a comet.
The half-minute trajectory correction maneuver, which adjusts the spacecraft's flight path, began at about 1 p.m. PST (4 p.m. EST) on Monday, Feb. 7. The 30-second-long firing of the spacecraft's rockets consumed about 69 grams (2.4 ounces) of fuel and changed the spacecraft's speed by 0.56 meters per second (1.3 mph).
NASA's plan for the Stardust-NExT mission is to fly the spacecraft to a point in space about 200 kilometers (124 miles) from comet Tempel 1 at the time of its closest approach. During the encounter, the spacecraft will take images of the surface of comet Tempel 1 to observe what changes have occurred since a NASA spacecraft last visited. (NASA's Deep Impact flew by Tempel 1 in July 2005).
Along with the high-resolution images of the comet's surface, Stardust-NExT will also measure the composition, size distribution and flux of dust emitted into the coma, and provide important new information about how comets evolve.
Stardust was launched on Feb. 7, 1999. This current Stardust-NExT target is a bonus mission for the comet chaser, which flew past comet Wild 2 in 2004 and returned particles from its coma to Earth.
While its sample return capsule parachuted to Earth in January 2006, mission controllers were placing the still-viable spacecraft on a path that would allow NASA the opportunity to re-use the already-proven flight system if a target of opportunity presented itself. In January 2007, NASA re-christened the mission "Stardust-NExT" (New Exploration of Tempel), and the Stardust team began a four-and-a-half year journey for the spacecraft to comet Tempel 1. The spacecraft has traveled more than 3.5 billion miles since launch.
On Feb. 6th, NASA's twin STEREO probes moved into position on opposite sides of the sun, and they are now beaming back uninterrupted images of the entire star—front and back.
"For the first time ever, we can watch solar activity in its full 3-dimensional glory," says Angelos Vourlidas, a member of the STEREO science team at the Naval Research Lab in Washington, DC.
NASA released a 'first light' 3D movie on, naturally, Super Bowl Sunday:
"This is a big moment in solar physics," says Vourlidas. "STEREO has revealed the sun as it really is--a sphere of hot plasma and intricately woven magnetic fields."
Each STEREO probe photographs half of the star and beams the images to Earth. Researchers combine the two views to create a sphere. These aren't just regular pictures, however. STEREO's telescopes are tuned to four wavelengths of extreme ultraviolet radiation selected to trace key aspects of solar activity such as flares, tsunamis and magnetic filaments. Nothing escapes their attention.
"With data like these, we can fly around the sun to see what's happening over the horizon—without ever leaving our desks," says STEREO program scientist Lika Guhathakurta at NASA headquarters. "I expect great advances in theoretical solar physics and space weather forecasting."
Consider the following: In the past, an active sunspot could emerge on the far side of the sun completely hidden from Earth. Then, the sun's rotation could turn that region toward our planet, spitting flares and clouds of plasma, with little warning.
"Not anymore," says Bill Murtagh, a senior forecaster at NOAA's Space Weather Prediction Center in Boulder, Colorado. "Farside active regions can no longer take us by surprise. Thanks to STEREO, we know they're coming."
NOAA is already using 3D STEREO models of CMEs (billion-ton clouds of plasma ejected by the sun) to improve space weather forecasts for airlines, power companies, satellite operators, and other customers. The full sun view should improve those forecasts even more.
The forecasting benefits aren't limited to Earth.
"With this nice global model, we can now track solar storms heading toward other planets, too," points out Guhathakurta. "This is important for NASA missions to Mercury, Mars, asteroids … you name it."
NASA has been building toward this moment since Oct. 2006 when the STEREO probes left Earth, split up, and headed for positions on opposite sides of the sun (movie). Feb. 6, 2011, was the date of "opposition"—i.e., when STEREO-A and -B were 180 degrees apart, each looking down on a different hemisphere. NASA's Earth-orbiting Solar Dynamics Observatory is also monitoring the sun 24/7. Working together, the STEREO-SDO fleet should be able to image the entire globe for the next 8 years.
The new view could reveal connections previously overlooked. For instance, researchers have long suspected that solar activity can "go global," with eruptions on opposite sides of the sun triggering and feeding off of one another. Now they can actually study the phenomenon. The Great Eruption of August 2010 engulfed about 2/3rd of the stellar surface with dozens of mutually interacting flares, shock waves, and reverberating filaments. Much of the action was hidden from Earth, but plainly visible to the STEREO-SDO fleet.
"There are many fundamental puzzles underlying solar activity," says Vourlidas. "By monitoring the whole sun, we can find missing pieces."
Researchers say these first-look whole sun images are just a hint of what's to come. Movies with even higher resolution and more action will be released in the days and weeks ahead as more data are processed. Stay tuned!
With input from scientists around the world, American and European scientists working on the potential next new mission to the Jupiter system have articulated their joint vision for the Europa Jupiter System Mission. The mission is a proposed partnership between NASA and the European Space Agency. The scientists on the joint NASA-ESA definition team agreed that the overarching science theme for the Europa Jupiter System Mission will be "the emergence of habitable worlds around gas giants."
The proposed Europa Jupiter System Mission would provide orbiters around two of Jupiter's moons: a NASA orbiter around Europa called the Jupiter Europa Orbiter, and an ESA orbiter around Ganymede called the Jupiter Ganymede Orbiter.
"We've reached hands across the Atlantic to define a mission to Jupiter's water worlds," said Bob Pappalardo, the pre-project scientist for the proposed Jupiter Europa Orbiter, who is based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The Europa Jupiter System Mission will create a leap in scientific knowledge about the moons of Jupiter and their potential to harbor life."
The new reports integrate goals that were being separately developed by NASA and ESA working groups into one unified strategy.
The ESA report is being presented to the European public and science community this week, and the NASA report was published online in December. The NASA report is available at http://www.lpi.usra.edu/opag .
The proposed mission singles out the icy moons Europa and Ganymede as special worlds that can lead to a broader understanding of the Jovian system and of the possibility of life in our solar system and beyond. They are natural laboratories for analyzing the nature, evolution and potential habitability of icy worlds, because they are believed to present two different kinds of sub-surface oceans.
The Jupiter Europa Orbiter would characterize the relatively thin ice shell above Europa's ocean, the extent of that ocean, the materials composing its internal layers, and the way surface features such as ridges and "freckles" formed. It will also identify candidate sites for potential future landers. Instruments that might be on board could include a laser altimeter, an ice-penetrating radar, spectrometers that can obtain data in visible, infrared and ultraviolet radiation, and cameras with narrow- and wide-angle capabilities. The actual instruments to fly would be selected through a NASA competitive call for proposals.
Ganymede is thought to have a thicker ice shell, with its interior ocean sandwiched between ice above and below. ESA's Jupiter Ganymede Orbiter would investigate this different kind of internal structure. The Jupiter Ganymede Orbiter would also study the intrinsic magnetic field that makes Ganymede unique among all the solar system's known moons. This orbiter, whose instruments would also be chosen through a competitive process, could include a laser altimeter, spectrometers and cameras, plus additional fields-and-particles instruments
The two orbiters would also study other large Jovian moons, Io and Callisto, with an eye towards exploring the Jupiter system as an archetype for other gas giant planets.
NASA and ESA officials gave the Europa Jupiter System Mission proposal priority status for continued study in 2009, agreeing that it was the most technically feasible of the outer solar system flagship missions under consideration.
Over the next few months, NASA officials will be analyzing the joint strategy and awaiting the outcome of the next Planetary Science Decadal Survey by the National Research Council of the U.S. National Academies. That survey will serve as a roadmap for new NASA planetary missions for the decade beginning 2013.
Sand dunes in a vast area of northern Mars long thought to be frozen in time are changing with both sudden and gradual motions, according to research using images from a NASA orbiter.
These dune fields cover an area the size of Texas in a band around the planet at the edge of Mars' north polar cap. The new findings suggest they are among the most active landscapes on Mars. However, few changes in these dark-toned dunes had been detected before a campaign of repeated imaging by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter, which reached Mars five years ago next month.
Scientists had considered the dunes to be fairly static, shaped long ago when winds on the planet's surface were much stronger than those seen today, said HiRISE Deputy Principal Investigator Candice Hansen of the Planetary Science Institute, Tucson, Ariz. Several sets of before-and-after images from HiRISE over a period covering two Martian years -- four Earth years -- tell a different story.
"The numbers and scale of the changes have been really surprising," said Hansen.
A report by Hansen and co-authors in this week's edition of the journal Science identifies the seasonal coming and going of carbon-dioxide ice as one agent of change, and stronger-than-expected wind gusts as another.
A seasonal layer of frozen carbon dioxide, or dry ice, blankets the region in winter and changes directly back to gaseous form in the spring.
"This gas flow destabilizes the sand on Mars sand dunes, causing sand avalanches and creating new alcoves, gullies and sand aprons on Martian dunes," she said. "The level of erosion in just one Mars year was really astonishing. In some places, hundreds of cubic yards of sand have avalanched down the face of the dunes."
Wind drives other changes. Especially surprising was the discovery that scars of past sand avalanches could be partially erased by wind in just one Mars year. Models of Mars' atmosphere do not predict wind speeds adequate to lift sand grains, and data from Mars landers show high winds are rare.
"Perhaps polar weather is more conducive to high wind speeds," Hansen said.
In all, modifications were seen in about 40 percent of these far-northern monitoring sites over the two-Mars-year period of the study.
Related HiRISE research previously identified gully-cutting activity in smaller fields of sand dunes covered by seasonal carbon-dioxide ice in Mars' southern hemisphere. A report four months ago showed that those changes coincided with the time of year when ice builds up.
"The role of the carbon-dioxide ice is getting clearer," said Serina Diniega of NASA's Jet Propulsion Laboratory, Pasadena, Calif., lead author of the earlier report and a co-author of the new report. "In the south, we saw before-and-after changes and connected the timing with the carbon-dioxide ice. In the north, we're seeing more of the process of the seasonal changes and adding more evidence linking the changes with the carbon dioxide."
Researchers are using HiRISE to repeatedly photograph dunes at all latitudes, to understand winds in the current climate on Mars. Dunes at latitudes lower than the reach of the seasonal carbon-dioxide ice do not show new gullies. Hansen said, "It's becoming clear that there are very active processes on Mars associated with the seasonal polar caps."
The new findings contribute to efforts to understand what features and landscapes on Mars can be explained by current processes, and which require different environmental conditions.
"Understanding how Mars is changing today is a key first step to understanding basic planetary processes and how Mars changed over time," said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, Tucson, a co-author of both reports. "There's lots of current activity in areas covered by seasonal carbon-dioxide frost, a process we don't see on Earth. It's important to understand the current effects of this unfamiliar process so we don't falsely associate them with different conditions in the past."
The University of Arizona Lunar and Planetary Laboratory operates the HiRISE camera, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems, Denver, built the orbiter.
Scientists using NASA's Kepler, a space telescope, recently discovered six planets made of a mix of rock and gases orbiting a single sun-like star, known as Kepler-11, which is located approximately 2,000 light years from Earth.
"The Kepler-11 planetary system is amazing," said Jack Lissauer, a planetary scientist and a Kepler science team member at NASA's Ames Research Center, Moffett Field, Calif. "It’s amazingly compact, it’s amazingly flat, there’s an amazingly large number of big planets orbiting close to their star - we didn’t know such systems could even exist."
In other words, Kepler-11 has the fullest, most compact planetary system yet discovered beyond our own.
"Few stars are known to have more than one transiting planet, and Kepler-11 is the first known star to have more than three," said Lissauer. "So we know that systems like this are not common. There’s certainly far fewer than one percent of stars that have systems like Kepler-11. But whether it’s one in a thousand, one in ten thousand or one in a million, that we don’t know, because we only have observed one of them."
All of the planets orbiting Kepler-11, a yellow dwarf star, are larger than Earth, with the largest ones being comparable in size to Uranus and Neptune. The innermost planet, Kepler-11b, is ten times closer to its star than Earth is to the sun. Moving outwards, the other planets are Kepler-11c, Kepler-11d, Kepler-11e, Kepler-11f, and the outermost planet, Kepler-11g, which is twice as close to its star than Earth is to the sun.
"The five inner planets are all closer to their star than any planet is to our sun and the sixth planet is still fairly close," said Lissauer.
If placed in our solar system, Kepler-11g would orbit between Mercury and Venus, and the other five planets would orbit between Mercury and our sun. The orbits of the five inner planets in the Kepler-11 planetary system are much closer together than any of the planets in our solar system. The inner five exoplanets have orbital periods between 10 and 47 days around the dwarf star, while Kepler-11g has a period of 118 days.
"By measuring the sizes and masses of the five inner planets, we have determined they are among the smallest confirmed exoplanets, or planets beyond our solar system," said Lissauer. "These planets are mixtures of rock and gases, possibly including water. The rocky material accounts for most of the planets' mass, while the gas takes up most of their volume."
According to Lissauer, Kepler-11 is a remarkable planetary system whose architecture and dynamics provide clues about its formation. The planets Kepler-11d, Kepler-11e and Kepler-11f have a significant amount of light gas, which Lissauer says indicates that at least these three planets formed early in the history of the planetary system, within a few million years.
A planetary system is born when a molecular cloud core collapses to form a star. At this time, disks of gas and dust in which planets form, called protoplanetary disks, surround the star. Protoplanetary disks can be seen around most stars that are less than a million years old, but few stars more than five million years old have them. This leads scientists to theorize that planets which contain significant amounts of gas form relatively quickly in order to obtain gases before the disk disperses.
The Kepler spacecraft will continue to return science data about the new Kepler-11 planetary system for the remainder of its mission. The more transits Kepler sees, the better scientists can estimate the sizes and masses of planets.
"These data will enable us to calculate more precise estimates of the planet sizes and masses, and could allow us to detect more planets orbiting the Kepler-11 star," said Lissauer. "Perhaps we could find a seventh planet in the system, either because of its transits or from the gravitational tugs it exerts on the six planets that we already see. We’re going to learn a fantastic amount about the diversity of planets out there, around stars within our galaxy."
A space observatory, Kepler looks for the data signatures of planets by measuring tiny decreases in the brightness of stars when planets cross in front of, or transit, them. The size of the planet can be derived from the change in the star's brightness. The temperature can be estimated from the characteristics of the star it orbits and the planet's orbital period.
The Kepler science team is using ground-based telescopes, as well as the Spitzer Space Telescope, to perform follow-up observations on planetary candidates and other objects of interest found by the spacecraft. The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these other observations help determine which of the candidates can be identified as planets.
Kepler will continue conducting science operations until at least November 2012, searching for planets as small as Earth, including those that orbit stars in the habitable zone, where liquid water could exist on the surface of the planet. Since transits of planets in the habitable zone of solar-like stars occur about once a year and require three transits for verification, it is predicted to take at least three years to locate and verify an Earth-size planet.
"Kepler can only see 1/400 of the sky," said William Borucki of NASA’s Ames Research Center, Moffett Field, Calif., and the mission’s science principal investigator. "Kepler can find only a small fraction of the planets around the stars it looks at because the orbits aren’t aligned properly. If you account for those two factors, our results indicate there must be millions of planets orbiting the stars that surround our sun."
Kepler is NASA's tenth Discovery mission. Ames is responsible for the ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., managed the Kepler mission development. Ball Aerospace and Technologies Corp., Boulder, Colo., was responsible for developing the Kepler flight system, and along with the Laboratory for Atmospheric and Space Physics at the University of Colorado, is supporting mission operations. Ground observations necessary to confirm the discoveries were conducted at the Keck I in Hawaii; Hobby-Ebberly and Harlan J. Smith 2.7m in Texas; Hale and Shane in California; WIYN, MMT and Tillinghast in Arizona, and the Nordic Optical in the Canary Islands, Spain.
NASA's Time History of Events and Macroscale Interaction during Substorms (THEMIS) spacecraft combined with computer models have helped track the origin of the energetic particles in Earth's magnetic atmosphere that appear during a kind of space weather called a substorm. Understanding the source of such particles and how they are shuttled through Earth's atmosphere is crucial to better understanding the Sun's complex space weather system and thus protect satellites or even humans in space.
The results show that these speedy electrons gain extra energy from changing magnetic fields far from the origin of the substorm that causes them. THEMIS, which consists of five orbiting satellites, helped provide these insights when three of the spacecraft traveled through a large substorm on February 15, 2008. This allowed scientists to track changes in particle energy over a large distance. The observations were consistent with numerical models showing an increase in energy due to changing magnetic fields, a process known as betatron acceleration.
"The origin of fast electrons in substorms has been a puzzle," says Maha Ashour-Abdalla, the lead author of a Nature Physics paper that appeared online on January 30, 2011 on the subject and a physicist at the University of California, Los Angeles. "It hasn't been clear until now if they got their burst of speed in the middle of the storm, or from some place further away."
Substorms originate opposite the sun on Earth's "night side," at a point about a third of the distance to the moon. At this point in space, energy and particles from the solar wind store up over time. This is also a point where the more orderly field lines near Earth -- where they look like two giant ears on either side of the globe, a shape known as a dipole since the lines bow down to touch Earth at the two poles – can distort into long lines and sometimes pull apart and "reconnect." During reconnection, the stored energy is released in explosions that send particles out in all directions. But reconnection is a magnetic phenomenon and scientists don't know the exact mechanism that creates speeding particles from that phenomenon.
"For thirty years, one of the questions about the magnetic environment around Earth has been, 'how do magnetic fields give rise to moving, energetic particles?'" says NASA scientist Melvyn Goldstein, chief of the Geospace Physics Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Md., and another author on the paper. "We need to know such things to help plan the next generation of reconnection research instruments such as the Magnetospheric MultiScale mission (MMS) due to launch in 2014. MMS needs to look in the right place and for the correct signatures of particle energization."
In the early 1980s, scientists hypothesized that the quick, high-energy particles might get their speed from rapidly changing magnetic fields. Changing magnetic fields can cause electrons to zoom along a corkscrew path by the betatron effect.
Indeed, electrons moving toward Earth from a substorm will naturally cross a host of changing magnetic fields as those long, stretched field lines far away from Earth relax back to the more familiar dipole field lines closer to Earth, a process called dipolarization. Betatron acceleration causes the particles to gain energy and speed much farther away from the initial reconnection site. But in the absence of observations that could simultaneously measure data near the reconnection site and closer to Earth, the hypothesis was hard to prove or contradict.
THEMIS, however, was specifically designed to study the formation of substorms. It launched with five spacecraft, which can be spread out over some 44,000 miles – a perfect tool for examining different areas of Earth's magnetic environment at the same time. Near midnight, on February 15, 2008, three of the satellites moving through Earth's magnetic tail, about 36,000 miles from Earth, traveled through a large substorm.
"I looked at the THEMIS data for that substorm," says Ashour-Abdalla, "and saw there was a direct correlation of the increased particle energy at the origin with the region of dipolarization nearer to Earth."
To examine the data, Ashour-Abdalla and a team of researchers from UCLA, Nanchang University in China, NASA Goddard Space Flight Center, and the University of Maryland, Baltimore, used their expertise with computer modeling to simulate the complex dynamics that occur in space. The team began with spacecraft data from an ESA mission called Cluster that was in the solar wind at the time of the substorm. Using these observations of the solar environment, they modeled large scale electric and magnetic fields in space around Earth. Then they modeled the future fate of the various particles observed.
When the team looked at their models they saw that electrons near the reconnection sites didn't gain much energy. But as they looked closer to Earth, where the THEMIS satellites were located, their model showed particles that had some ten times as much energy – just as THEMIS had in fact observed.
This is consistent with the betatron acceleration model. The electrons gain a small amount of energy from the reconnection and then travel toward Earth, crossing many changing magnetic field lines. These fields produce betatronic acceleration just as Kivelson predicted in the early 1980s, speeding the electrons up substantially.
"This research shows the great science that can be accomplished when modelers, theorists and observationalists join forces," says astrophysicist Larry Kepko, who is a deputy project scientist for the THEMIS mission at Goddard. "THEMIS continues to yield critical insights into the dynamic processes that produce the space weather that affects Earth."
Launched in 2007, THEMIS was NASA's first five-satellite mission launched aboard a single rocket. The unique constellation of satellites provided scientists with data to help resolve the mystery of how Earth's magnetosphere stores and releases energy from the sun by triggering geomagnetic substorms. Two of the satellites have been renamed ARTEMIS and are in the process of moving to a new orbit around the moon. They are due to reach their final lunar orbit in July 2011. The three remaining THEMIS satellites continue to study substorms.
THEMIS is managed by NASA's Goddard Space Flight Center for the agency's Science Mission Directorate. The Space Sciences Laboratory at the University of California, Berkeley, is responsible for project management, space and ground-based instruments, mission integration, mission operations and science. ATK (formerly Swales Aerospace), Beltsville, Md., built the THEMIS probes. THEMIS is an international project conducted in partnership with Germany, France, Austria, and Canada.
A hurtling asteroid about the size of the Titanic caused the scar that appeared in Jupiter's atmosphere on July 19, 2009, according to two papers published recently in the journal Icarus.
Data from three infrared telescopes enabled scientists to observe the warm atmospheric temperatures and unique chemical conditions associated with the impact debris. By piecing together signatures of the gases and dark debris produced by the impact shockwaves, an international team of scientists was able to deduce that the object was more likely a rocky asteroid than an icy comet. Among the teams were those led by Glenn Orton, an astronomer at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Leigh Fletcher, researcher at Oxford University, U.K., who started the work while he was a postdoctoral fellow at JPL.
"Both the fact that the impact itself happened at all and the implication that it may well have been an asteroid rather than a comet shows us that the outer solar system is a complex, violent and dynamic place, and that many surprises may be out there waiting for us," said Orton. "There is still a lot to sort out in the outer solar system."
The new conclusion is also consistent with evidence from results from NASA's Hubble Space Telescope indicating the impact debris in 2009 was heavier or denser than debris from comet Shoemaker-Levy 9, the last known object to hurl itself into Jupiter's atmosphere in 1994.
Before this collision, scientists had thought that the only objects that hit Jupiter were icy comets whose unstable orbits took them close enough to Jupiter to be sucked in by the giant planet's gravitational attraction. Those comets are known as Jupiter-family comets. Scientists thought Jupiter had already cleared most other objects, such as asteroids, from its sphere of influence. Besides Shoemaker-Levy, scientists know of only two other impacts in the summer of 2010, which lit up Jupiter's atmosphere.
The July 19, 2009 object likely hit Jupiter between 9 a.m. and 11 a.m. UTC. Amateur astronomer Anthony Wesley from Australia was the first to notice the scar on Jupiter, which appeared as a dark spot in visible wavelengths. The scar appeared at mid-southern latitudes. Wesley tipped off Orton and colleagues, who immediately used existing observing time at NASA's Infrared Telescope Facility in Mauna Kea, Hawaii, the following night and proposed observing time on a host of other ground-based observatories, including the Gemini North Observatory in Hawaii, the Gemini South Telescope in Chile, and the European Southern Observatory's Very Large Telescope in Chile. Data were acquired at regular intervals during the week following the 2009 collision.
The data showed that the impact had warmed Jupiter's lower stratosphere by as much as 3 to 4 Kelvin at about 42 kilometers above its cloudtops. Although 3 to 4 Kelvin does not sound like a lot, it is a significant deposition of energy because it is spread over such an enormous area.
Plunging through Jupiter's atmosphere, the object created a channel of super-heated atmospheric gases and debris. An explosion deep below the clouds – probably releasing at least around 200 trillion trillion ergs of energy, or more than 5 gigatons of TNT -- then launched debris material back along the channel, above the cloud tops, to splash back down into the atmosphere, creating the aerosol particulates and warm temperatures observed in the infrared. The blowback dredged up ammonia gas and other gases from a lower part of the atmosphere known as the troposphere into a higher part of the atmosphere known as the stratosphere.
"Comparisons between the 2009 images and the Shoemaker-Levy 9 results are beginning to show intriguing differences between the kinds of objects that hit Jupiter," Fletcher said. "The dark debris, the heated atmosphere and upwelling of ammonia were similar for this impact and Shoemaker-Levy, but the debris plume in this case didn't reach such high altitudes, didn't heat the high stratosphere, and contained signatures for hydrocarbons, silicates and silicas that weren't seen before. The presence of hydrocarbons, and the absence of carbon monoxide, provide strong evidence for a water-depleted impactor in 2009."
The detection of silica in this mixture of Jovian atmospheric gases, processed bits from the impactor and byproducts of high-energy chemical reactions was significant because abundant silica could only be produced in the impact itself, by a strong rocky body capable of penetrating very deeply into the Jovian atmosphere before exploding, but not by a much weaker comet nucleus. Assuming that the impactor had a rock-like density of around 2.5 grams per cubic centimeter (160 pounds per cubic foot), scientists calculated a likely diameter of 200 to 500 meters (700 to 1,600 feet).
Scientists computed the set of possible orbits that would bring an object into Jupiter in the right range of times and at the right locations. Then they searched the catalog of known asteroids and comets to find the kinds of objects in these orbits. An object named 2005 TS100 – which is probably an asteroid but could be an extinct comet – was one of the closest matches. Although this object was not the actual impactor, it has a very chaotic orbit and made several very close approaches to Jupiter in computer models, demonstrating that an asteroid could have hurtled into Jupiter.
"We weren't expecting to find that an asteroid was the likely culprit in this impact, but we've now learned Jupiter is getting hit by a diversity of objects," said Paul Chodas, a scientist at NASA's Near-Earth Object Program Office at JPL. " Asteroid impacts on Jupiter were thought to be quite rare compared to impacts from the so-called 'Jupiter-family comets,' but now it seems there may be a significant population of asteroids in this category."
Scientists are still working to figure out what that frequency at Jupiter is, but asteroids of this size hit Earth about once every 100,000 years. The next steps in this investigation will be to use detailed simulations of the impact to refine the size and properties of the impactor, and to continue to use imaging at infrared, as well as visible wavelengths, to search for debris from future impacts of this size or smaller.
JPL is managed for NASA by the California Institute of Technology in Pasadena.
A massive star flung away from its former companion is plowing through space dust. The result is a brilliant bow shock, seen here as a yellow arc in a new image from NASA's Wide-field Infrared Survey Explorer, or WISE.
The star, named Zeta Ophiuchi, is huge, with a mass of about 20 times that of our sun. In this image, in which infrared light has been translated into visible colors we see with our eyes, the star appears as the blue dot inside the bow shock.
Zeta Ophiuchi once orbited around an even heftier star. But when that star exploded in a supernova, Zeta Ophiuchi shot away like a bullet. It's traveling at a whopping 54,000 miles per hour (or 24 kilometers per second), and heading toward the upper left area of the picture.
As the star tears through space, its powerful winds push gas and dust out of its way and into what is called a bow shock. The material in the bow shock is so compressed that it glows with infrared light that WISE can see. The effect is similar to what happens when a boat speeds through water, pushing a wave in front of it.
This bow shock is completely hidden in visible light. Infrared images like this one from WISE are therefore important for shedding new light on the region.
JPL manages and operates WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by NASA's Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
A test photo of British Columbia's snow-capped west coast mountains is the first official image taken from the International Space Station's new Window Observational Research Facility, or WORF.
The image was taken to test the functionality of the control computer and camera associated with EarthKAM, an educational outreach project that allows Earth bound middle school students to take pictures of our home planet from the unique perspective of the space station, 220 miles above the Earth's surface. WORF was delivered to the station on the STS-131 mission of space shuttle Discovery in April 2010.
EarthKAM uses a Nikon D2X digital camera, and was set up in the WORF by Expedition 26 NASA flight engineer Cady Coleman on Jan. 17. EarthKAM ground controllers took the test photo. Expedition 26 also includes Commander Scott Kelly of NASA, European Space Agency astronaut Paolo Nespoli, and Russian cosmonauts Oleg Skripochka, Alexander Kaleri and Dmitry Kontratyev.
The test photo, designated ISS EarthKAM Image Winter 2011 #9362, is of an area of British Columbia, Canada, just north of Vancouver Island. The center point of the photo is 51 degrees, 48 minutes north and 127 degrees, 54 minutes west. Visible in the photo are Calvert and Hecate Islands on the Canadian coast and the southern portion of Hunter Island. Also visible are glaciers of the Ha-iltzuk Icefield near the 8,720-foot-tall -- 2,658-meter-tall -- Mount Somolenko. Mount Somolenko is a volcanic peak in southwestern British Columbia, that lies in a circular volcanic depression in the Pacific Ranges of the Coast Mountains called the Silverthrone Caldera.
While this isn't a particularly unique Earth observation image, it is notable that even though it was taken with a wider angle, 50mm lens and covers an area 124 miles/200 kilometers, by 83 miles/134 kilometers, it can be enlarged by more than 400 percent while keeping features in the photo identifiable. This is made possible by the high-quality optics of the Earth-facing window of the Destiny Laboratory, which was launched on Feb. 7, 2001.
The installation of WORF allowed removal of an internal "scratch pane" that has reduced the quality of images taken though the window. WORF also provides a highly stable mounting platform to hold cameras and sensors rock steady at the window, as well as the power, command, data, and cooling connections needed for their operation.
"With the WORF finally in place we can now for the first time make full use of the investment we made in having an optical quality window onboard the station for Earth science and observation," said former astronaut Mario Runco, who was part of the design and development teams for the Destiny window and WORF, and now serves as NASA's lead for Spacecraft Window Optics and Window/WORF Utilization at NASA's Johnson Space Center, Houston.
"We are very excited to have a new camera system that appears to be functional and taking incredible images," said Karen Flammer, who manages EarthKAM operations at the University of California, can Diego. "The first student images were taken by Parkview Montessori in the Jackson-Madison County (Tenn.) School System, and Public School 229 - Dyker in Brooklyn, N.Y., part of the New York City Department of Education.
Parkview teacher Vickie LeCroy's students plan to study landforms, such as islands, mountains and deserts in the image they took of Mexico, and Dyker teacher Camille Fratantoni’s students plan to enrich their studies of earth science and learn more about NASA missions.
In addition to their educational outreach role with EarthKAM, the combination of the window and WORF adds to the station's capabilities as an Earth science remote sensing platform for high-resolution cameras and multi and hyperspectral imagers. Images from space have many applications, such as in the study of climate and meteorology; oceanography; geology and volcanology; coastal, agricultural, ranch and forestry management; and disaster assessments and management.
These images by NASA's Hubble Space Telescope show off two dramatically different face-on views of the spiral galaxy M51, dubbed the Whirlpool Galaxy.
The image at left, taken in visible light, highlights the attributes of a typical spiral galaxy, including graceful, curving arms, pink star-forming regions, and brilliant blue strands of star clusters.
In the image at right, most of the starlight has been removed, revealing the Whirlpool's skeletal dust structure, as seen in near-infrared light. This new image is the sharpest view of the dense dust in M51. The narrow lanes of dust revealed by Hubble reflect the galaxy's moniker, the Whirlpool Galaxy, as if they were swirling toward the galaxy's core.
To map the galaxy's dust structure, researchers collected the galaxy's starlight by combining images taken in visible and near-infrared light. The visible-light image captured only some of the light; the rest was obscured by dust. The near-infrared view, however, revealed more starlight because near-infrared light penetrates dust. The researchers then subtracted the total amount of starlight from both images to see the galaxy's dust structure.
The red color in the near-infrared image traces the dust, which is punctuated by hundreds of tiny clumps of stars, each about 65 light-years wide. These stars have never been seen before. The star clusters cannot be seen in visible light because dense dust enshrouds them. The image reveals details as small as 35 light-years across.
Astronomers expected to see large dust clouds, ranging from about 100 light-years to more than 300 light-years wide. Instead, most of the dust is tied up in smooth and diffuse dust lanes. An encounter with another galaxy may have prevented giant clouds from forming.
Probing a galaxy's dust structure serves as an important diagnostic tool for astronomers, providing invaluable information on how the gas and dust collapse to form stars. Although Hubble is providing incisive views of the internal structure of galaxies such as M51, the planned James Webb Space Telescope (JWST) is expected to produce even crisper images.
Researchers constructed the image by combining visible-light exposures from Jan. 18 to 22, 2005, with the Advanced Camera for Surveys (ACS), and near-infrared light pictures taken in December 2005 with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).
Plants are fundamental to life on Earth, converting light and carbon dioxide into food and oxygen. Plant growth may be an important part of human survival in exploring space, as well. Gardening in space has been part of the International Space Station from the beginning -- whether peas grown in the Lada greenhouse or experiments in the Biomass Production System. The space station offers unique opportunities to study plant growth and gravity, something that cannot be done on Earth.
The latest experiment that has astronauts putting their green thumbs to the test is Hydrotropism and Auxin-Inducible Gene expression in Roots Grown Under Microgravity Conditions, known as HydroTropi. Operations were conducted October 18-21, 2010, HydroTropi is a Japan Aerospace Exploration Agency (JAXA)-run study that looks at directional root growth. In microgravity, roots grow latterly or sideways, instead of up and down like they do under Earth’s gravitational forces.
Using cucumber plants (scientific name Cucumis sativus), investigators look to determine whether hydrotropic -- plant root orientation due to water—response can control the direction of root growth in microgravity. To perform the HydroTropi experiment, astronauts transport the cucumber seeds from Earth to the space station and then coax them into growth. The seeds, which reside in Hydrotropism chambers, undergo 18 hours of incubation in a Cell Biology Experiment Facility or CBEF. Then the crewmembers activate the seeds with water or a saturated salt solution, followed by a second application of water 4 to 5 hours later. The crew harvests the cucumber seedlings and preserves them using fixation tubes called Kenney Space Center Fixation Tubes or KFTs, which then store in one of the station MELFI freezers to await return to Earth.
The results from HydroTropi, which returns to Earth on STS-133, will help investigators to better understand how plants grow and develop at a molecular level. The experiment will demonstrate a plant’s ability to change growth direction in response to gravity (gravitropism) vs. directional growth in response to water (hydrotropism). By looking at the reaction of the plants to the stimuli and the resulting response of differential auxin -- the compound regulating the growth of plants -- investigators will learn about plants inducible gene expression. In space, investigators hope HydroTropi will show them how to control directional root growth by using the hydrotropism stimulus; this knowledge may also lead to significant advancements in agriculture production on Earth.
In late 2010, NASA awarded contracts to three teams — Lockheed Martin, Northrop Grumman, The Boeing Company — to study advanced concept designs for aircraft that could take to the skies in the year 2025.
At the time of the award, the team gave NASA a sneak peek of the particular design they plan to pursue.
Each design looks very different, but all final designs have to meet NASA's goals for less noise, cleaner exhaust and lower fuel consumption. Each aircraft has to be able to do all of those things at the same time, which requires a complex dance of tradeoffs between all of the new advanced technologies that will be on these vehicles.
The proposed aircraft will also have to operate safely in a more modernized air traffic management system.
And each design has to fly up to 85 percent of the speed of sound; cover a range of approximately 7,000 miles; and carry between 50,000 and 100,000 pounds of payload, either passengers or cargo.
For the rest of this year, each team will be exploring, testing, simulating, keeping and discarding innovations and technologies to make their design a winner.
How different will the final designs look from these initial glimpses?
A deep survey of more than 200,000 stars in our Milky Way galaxy has unveiled the sometimes petulant behavior of tiny red dwarf stars. These stars, which are smaller than the Sun, can unleash powerful eruptions called flares that may release the energy of more than 100 million atomic bombs.
Red dwarfs are the most abundant stars in our universe and are presumably hosts to numerous planets. However, their erratic behavior could make life unpleasant, if not impossible, for many alien worlds. Flares are sudden eruptions of heated plasma that occur when powerful magnetic field lines in a star's atmosphere "reconnect," snapping like a rubber band and releasing vast amounts of energy. When they occur, flares would blast any planets orbiting the star with ultraviolet light, bursts of X-rays, and a gush of charged particles called a stellar wind.
Studying the light from 215,000 red dwarfs collected in observations by NASA's Hubble Space Telescope, astronomers found 100 stellar flares. The observations, taken over a seven-day period, constitute the largest continuous monitoring of red dwarf stars ever undertaken.
"We know that hyperactive young stars produce flares, but this study shows that even in fairly old stars that are several billion years old, flares are a fact of life," says astronomer Rachel Osten of the Space Telescope Science Institute in Baltimore, Md., leader of the research team. "Life could be rough for any planets orbiting close enough to these flaring stars. Their heated atmospheres could puff up and might get stripped away."
Osten and her team, including Adam Kowalski of the University of Washington in Seattle, found that the red dwarf stars flared about 15 times less frequently than in previous surveys, which observed younger and less massive stars.
The stars in this study were originally part of a search for planets. Hubble monitored the stars continuously for a week in 2006, looking for the signature of planets passing in front of them. The stars were photographed by Hubble's Advanced Camera for Surveys during the extrasolar-planet survey called the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS).
Osten and Kowalski realized that this powerful census contained important information on the stars themselves, and they took advantage of it. They searched the Hubble data, looking for a slight increase in the brightness of red dwarfs, a signature of flares. Some of the stars grew up to 10 percent brighter over a short period of time, which is actually much brighter than flares on our Sun. The average duration of the flares was 15 minutes. A few stars produced multiple flares.
The astronomers found that stars that periodically oscillate in brightness, called variable stars, were more prone to the short-term outbursts.
"We discovered that variable stars are about a thousand times more likely to flare than non-variable stars," Kowalski says. "The variable stars are rotating fast, which may mean they are in rapidly orbiting binary systems. If the stars possess large star spots, dark regions on a star's surface, that will cause the star's light to vary when the spots rotate in and out of view. Star spots are produced when magnetic field lines poke through the surface. So, if there are big spots, there is a large area covered by strong magnetic fields, and we found that those stars had more flares."
Although red dwarfs are smaller than the Sun, they have a deeper convection zone, where cells of hot gas bubble to the surface, like boiling oatmeal," Osten explains. This zone generates the magnetic field and enables red dwarfs to put out such energetic flares.
"The red dwarfs also have magnetic fields that are stronger than the Sun's," Osten continues. "They cover a much larger area than the Sun. Sunspots cover less than 1 percent of the Sun's surface, while red dwarfs can have star spots that cover half of their surfaces."
Kowalski will present the team's results on Jan. 10, 2011, at the American Astronomical Society meeting in Seattle, Wash.
