Wednesday, 22 February 2012
Tuesday, 21 February 2012
Saturday, 29 October 2011
Lincoln University Admissions
Office of the Registrar
PO Box 179
Lincoln University, PA 19352
Tel: (800) 739-4461 (484) 365- 8087
Fax: (484) 365-8116
Lincoln Hall, 2nd Floo
PO Box 179
Lincoln University, PA 19352
Tel: (800) 739-4461 (484) 365- 8087
Fax: (484) 365-8116
Lincoln Hall, 2nd Floo
Solar Storm Warning
March 10, 2006: It's official: Solar minimum has arrived. Sunspots have all but vanished. Solar flares are nonexistent. The sun is utterly quiet.
Like the quiet before a storm.
This week researchers announced that a storm is coming--the most intense solar maximum in fifty years. The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR). "The next sunspot cycle will be 30% to 50% stronger than the previous one," she says. If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958.
That was a solar maximum. The Space Age was just beginning: Sputnik was launched in Oct. 1957 and Explorer 1 (the first US satellite) in Jan. 1958. In 1958 you couldn't tell that a solar storm was underway by looking at the bars on your cell phone; cell phones didn't exist. Even so, people knew something big was happening when Northern Lights were sighted three times in Mexico. A similar maximum now would be noticed by its effect on cell phones, GPS, weather satellites and many other modern technologies.
Right: Intense auroras over Fairbanks, Alaska, in 1958
Like the quiet before a storm.
This week researchers announced that a storm is coming--the most intense solar maximum in fifty years. The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR). "The next sunspot cycle will be 30% to 50% stronger than the previous one," she says. If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958.
That was a solar maximum. The Space Age was just beginning: Sputnik was launched in Oct. 1957 and Explorer 1 (the first US satellite) in Jan. 1958. In 1958 you couldn't tell that a solar storm was underway by looking at the bars on your cell phone; cell phones didn't exist. Even so, people knew something big was happening when Northern Lights were sighted three times in Mexico. A similar maximum now would be noticed by its effect on cell phones, GPS, weather satellites and many other modern technologies.
Right: Intense auroras over Fairbanks, Alaska, in 1958
Super Storm on Saturn
May 19, 2011: NASA's Cassini spacecraft and a European Southern Observatory ground-based telescope are tracking the growth of a giant early-spring storm in Saturn's northern hemisphere so powerful that it stretches around the entire planet. The rare storm has been wreaking havoc for months and shooting plumes of gas high into the planet's atmosphere.
This false-color infrared image shows clouds of large ammonia ice particles dredged up by the powerful storm. Credit: Cassini. [more]
"Nothing on Earth comes close to this powerful storm," says Leigh Fletcher, a Cassini team scientist at the University of Oxford in the United Kingdom, and lead author of a study that appeared in this week's edition of Science Magazine. "A storm like this is rare. This is only the sixth one to be recorded since 1876, and the last was way back in 1990."
Cassini's radio and plasma wave science instrument first detected the large disturbance in December 2010, and amateur astronomers have been watching it ever since through backyard telescopes. As it rapidly expanded, the storm's core developed into a giant, powerful thunderstorm, producing a 3,000-mile-wide (5,000-kilometer-wide) dark vortex possibly similar to Jupiter's Great Red Spot.
This is the first major storm on Saturn observed by an orbiting spacecraft and studied at thermal infrared wavelengths. Infrared observations are key because heat tells researchers a great deal about conditions inside the storm, including temperatures, winds, and atmospheric composition. Temperature data were provided by the Very Large Telescope (VLT) on Cerro Paranal in Chile and Cassini's composite infrared spectrometer (CIRS), operated by NASA's Goddard Space Flight Center in Greenbelt, Md.
"Our new observations show that the storm had a major effect on the atmosphere, transporting energy and material over great distances -- creating meandering jet streams and forming giant vortices -- and disrupting Saturn's seasonal [weather patterns]," said Glenn Orton, a paper co-author, based at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
The violence of the storm -- the strongest disturbances ever detected in Saturn's stratosphere -- took researchers by surprise. What started as an ordinary disturbance deep in Saturn's atmosphere punched through the planet's serene cloud cover to roil the high layer known as the stratosphere.
Thermal infrared images of Saturn from the Very Large Telescope Imager and Spectrometer for the mid-Infrared (VISIR) instrument on the European Southern Observatory's Very Large Telescope, on Cerro Paranal, Chile, appear at center and on the right. An amateur visible-light image from Trevor Barry, of Broken Hill, Australia, appears on the left. The images were obtained on Jan. 19, 2011. [more]
"On Earth, the lower stratosphere is where commercial airplanes generally fly to avoid storms which can cause turbulence," says Brigette Hesman, a scientist at the University of Maryland in College Park who works on the CIRS team at Goddard and is the second author on the paper. "If you were flying in an airplane on Saturn, this storm would reach so high up, it would probably be impossible to avoid it."
A separate analysis using Cassini's visual and infrared mapping spectrometer, led by Kevin Baines of JPL, confirmed the storm is very violent, dredging up deep material in volumes several times larger than previous storms. Other Cassini scientists are studying the evolving storm and, they say, a more extensive picture will emerge soon.
This false-color infrared image shows clouds of large ammonia ice particles dredged up by the powerful storm. Credit: Cassini. [more]
"Nothing on Earth comes close to this powerful storm," says Leigh Fletcher, a Cassini team scientist at the University of Oxford in the United Kingdom, and lead author of a study that appeared in this week's edition of Science Magazine. "A storm like this is rare. This is only the sixth one to be recorded since 1876, and the last was way back in 1990."
Cassini's radio and plasma wave science instrument first detected the large disturbance in December 2010, and amateur astronomers have been watching it ever since through backyard telescopes. As it rapidly expanded, the storm's core developed into a giant, powerful thunderstorm, producing a 3,000-mile-wide (5,000-kilometer-wide) dark vortex possibly similar to Jupiter's Great Red Spot.
This is the first major storm on Saturn observed by an orbiting spacecraft and studied at thermal infrared wavelengths. Infrared observations are key because heat tells researchers a great deal about conditions inside the storm, including temperatures, winds, and atmospheric composition. Temperature data were provided by the Very Large Telescope (VLT) on Cerro Paranal in Chile and Cassini's composite infrared spectrometer (CIRS), operated by NASA's Goddard Space Flight Center in Greenbelt, Md.
"Our new observations show that the storm had a major effect on the atmosphere, transporting energy and material over great distances -- creating meandering jet streams and forming giant vortices -- and disrupting Saturn's seasonal [weather patterns]," said Glenn Orton, a paper co-author, based at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
The violence of the storm -- the strongest disturbances ever detected in Saturn's stratosphere -- took researchers by surprise. What started as an ordinary disturbance deep in Saturn's atmosphere punched through the planet's serene cloud cover to roil the high layer known as the stratosphere.
Thermal infrared images of Saturn from the Very Large Telescope Imager and Spectrometer for the mid-Infrared (VISIR) instrument on the European Southern Observatory's Very Large Telescope, on Cerro Paranal, Chile, appear at center and on the right. An amateur visible-light image from Trevor Barry, of Broken Hill, Australia, appears on the left. The images were obtained on Jan. 19, 2011. [more]
"On Earth, the lower stratosphere is where commercial airplanes generally fly to avoid storms which can cause turbulence," says Brigette Hesman, a scientist at the University of Maryland in College Park who works on the CIRS team at Goddard and is the second author on the paper. "If you were flying in an airplane on Saturn, this storm would reach so high up, it would probably be impossible to avoid it."
A separate analysis using Cassini's visual and infrared mapping spectrometer, led by Kevin Baines of JPL, confirmed the storm is very violent, dredging up deep material in volumes several times larger than previous storms. Other Cassini scientists are studying the evolving storm and, they say, a more extensive picture will emerge soon.
Free-Floating Planets May Be More Common Than Stars
May 18, 2011: Astronomers have discovered a new class of Jupiter-sized planets floating alone in the dark of space, away from the light of a star. The team believes these lone worlds are probably outcasts from developing planetary systems and, moreover, they could be twice as numerous as the stars themselves.
"Although free-floating planets have been predicted, they finally have been detected," said Mario Perez, exoplanet program scientist at NASA Headquarters in Washington. "[This has] major implications for models of planetary formation and evolution."
The discovery is based on a joint Japan-New Zealand survey that scanned the center of the Milky Way galaxy during 2006 and 2007, revealing evidence for up to 10 free-floating planets roughly the mass of Jupiter. The isolated orbs, also known as orphan planets, are difficult to spot, and had gone undetected until now. The planets are located at an average approximate distance of 10,000 to 20,000 light years from Earth.
This artist's concept illustrates a Jupiter-like planet alone in the dark of space, floating freely without a parent star. [larger image] [video]
This could be just the tip of the iceberg. The team estimates there are about twice as many free-floating Jupiter-mass planets as stars. In addition, these worlds are thought to be at least as common as planets that orbit stars. This adds up to hundreds of billions of lone planets in our Milky Way galaxy alone.
"Our survey is like a population census," said David Bennett, a NASA and National Science Foundation-funded co-author of the study from the University of Notre Dame in South Bend, Ind. "We sampled a portion of the galaxy, and based on these data, can estimate overall numbers in the galaxy."
The study, led by Takahiro Sumi from Osaka University in Japan, appears in the May 19 issue of the journal Nature. The survey is not sensitive to planets smaller than Jupiter and Saturn, but theories suggest lower-mass planets like Earth should be ejected from their stars more often. As a result, they are thought to be more common than free-floating Jupiters.
Previous observations spotted a handful of free-floating planet-like objects within star-forming clusters, with masses three times that of Jupiter. But scientists suspect the gaseous bodies form more like stars than planets. These small, dim orbs, called brown dwarfs, grow from collapsing balls of gas and dust, but lack the mass to ignite their nuclear fuel and shine with starlight. It is thought the smallest brown dwarfs are approximately the size of large planets.
A video from JPL describes the microlensing technique astronomers used to detect the orphan planets.
On the other hand, it is likely that some planets are ejected from their early, turbulent solar systems, due to close gravitational encounters with other planets or stars. Without a star to circle, these planets would move through the galaxy as our sun and others stars do, in stable orbits around the galaxy's center. The discovery of 10 free-floating Jupiters supports the ejection scenario, though it's possible both mechanisms are at play.
"If free-floating planets formed like stars, then we would have expected to see only one or two of them in our survey instead of 10," Bennett said. "Our results suggest that planetary systems often become unstable, with planets being kicked out from their places of birth."
The observations cannot rule out the possibility that some of these planets may be in orbit around distant stars, but other research indicates Jupiter-mass planets in such distant orbits are rare.
The survey, the Microlensing Observations in Astrophysics (MOA), is named in part after a giant wingless, extinct bird family from New Zealand called the moa. A 5.9-foot (1.8-meter) telescope at Mount John University Observatory in New Zealand is used to regularly scan the copious stars at the center of our galaxy for gravitational microlensing events. These occur when something, such as a star or planet, passes in front of another more distant star. The passing body's gravity warps the light of the background star, causing it to magnify and brighten. Heftier passing bodies, like massive stars, will warp the light of the background star to a greater extent,resulting in brightening events that can last weeks. Small planet-size bodies will cause less of a distortion, and brighten a star for only a few days or less.
A second microlensing survey group, the Optical Gravitational Lensing Experiment (OGLE), contributed to this discovery using a 4.2-foot (1.3 meter) telescope in Chile. The OGLE group also observed many of the same events, and their observations independently confirmed the analysis of the MOA group.
"Although free-floating planets have been predicted, they finally have been detected," said Mario Perez, exoplanet program scientist at NASA Headquarters in Washington. "[This has] major implications for models of planetary formation and evolution."
The discovery is based on a joint Japan-New Zealand survey that scanned the center of the Milky Way galaxy during 2006 and 2007, revealing evidence for up to 10 free-floating planets roughly the mass of Jupiter. The isolated orbs, also known as orphan planets, are difficult to spot, and had gone undetected until now. The planets are located at an average approximate distance of 10,000 to 20,000 light years from Earth.
This artist's concept illustrates a Jupiter-like planet alone in the dark of space, floating freely without a parent star. [larger image] [video]
This could be just the tip of the iceberg. The team estimates there are about twice as many free-floating Jupiter-mass planets as stars. In addition, these worlds are thought to be at least as common as planets that orbit stars. This adds up to hundreds of billions of lone planets in our Milky Way galaxy alone.
"Our survey is like a population census," said David Bennett, a NASA and National Science Foundation-funded co-author of the study from the University of Notre Dame in South Bend, Ind. "We sampled a portion of the galaxy, and based on these data, can estimate overall numbers in the galaxy."
The study, led by Takahiro Sumi from Osaka University in Japan, appears in the May 19 issue of the journal Nature. The survey is not sensitive to planets smaller than Jupiter and Saturn, but theories suggest lower-mass planets like Earth should be ejected from their stars more often. As a result, they are thought to be more common than free-floating Jupiters.
Previous observations spotted a handful of free-floating planet-like objects within star-forming clusters, with masses three times that of Jupiter. But scientists suspect the gaseous bodies form more like stars than planets. These small, dim orbs, called brown dwarfs, grow from collapsing balls of gas and dust, but lack the mass to ignite their nuclear fuel and shine with starlight. It is thought the smallest brown dwarfs are approximately the size of large planets.
A video from JPL describes the microlensing technique astronomers used to detect the orphan planets.
On the other hand, it is likely that some planets are ejected from their early, turbulent solar systems, due to close gravitational encounters with other planets or stars. Without a star to circle, these planets would move through the galaxy as our sun and others stars do, in stable orbits around the galaxy's center. The discovery of 10 free-floating Jupiters supports the ejection scenario, though it's possible both mechanisms are at play.
"If free-floating planets formed like stars, then we would have expected to see only one or two of them in our survey instead of 10," Bennett said. "Our results suggest that planetary systems often become unstable, with planets being kicked out from their places of birth."
The observations cannot rule out the possibility that some of these planets may be in orbit around distant stars, but other research indicates Jupiter-mass planets in such distant orbits are rare.
The survey, the Microlensing Observations in Astrophysics (MOA), is named in part after a giant wingless, extinct bird family from New Zealand called the moa. A 5.9-foot (1.8-meter) telescope at Mount John University Observatory in New Zealand is used to regularly scan the copious stars at the center of our galaxy for gravitational microlensing events. These occur when something, such as a star or planet, passes in front of another more distant star. The passing body's gravity warps the light of the background star, causing it to magnify and brighten. Heftier passing bodies, like massive stars, will warp the light of the background star to a greater extent,resulting in brightening events that can last weeks. Small planet-size bodies will cause less of a distortion, and brighten a star for only a few days or less.
A second microlensing survey group, the Optical Gravitational Lensing Experiment (OGLE), contributed to this discovery using a 4.2-foot (1.3 meter) telescope in Chile. The OGLE group also observed many of the same events, and their observations independently confirmed the analysis of the MOA group.
MSFC Earth-Sun Studies Featured at AGU
AGU
December 13, 1996
Fountains of electrified gases spewing from the Earth into space and pictures of the aurora during the day will be highlighted by the American Geophysical Union (AGU) annual winter conference in San Francisco Dec. 15-19.
AGU is one of the largest scientific bodies in the world and takes in everything from earthquakes to solar flares - including work by scientists at Marshall Space Flight Center's Space Sciences Laboratory (SSL) to understand what drives the aurora borealis and causes space storms that can black out cities.
At at three sessions during the AGU meeting, Marshall scientists will present their results in several papers, written with colleagues from other institutions, from the Thermal Ion Dynamics Experiment (TIDE) and the Ultraviolet Imager (UVI), two of several instruments aboard the Polar spacecraft launched in 1996.
TIDE recently confirmed that plasmas in the tail of the magnetosphere come from Earth's outer atmosphere being warmed by a flow of materials from space. The magnetosphere is formed by the Earth's magnetic field and buffers the planet from the constant wind of gases streaming from the sun.
Press briefings scheduled for the AGU Fall Meeting include:
Imaging Space Plasmas - Polar UVI and the Inner Magnetosphere Imager on which MSFC will have an important camera. Tuesday, Dec. 17, 12:45 p.m.
Sun-Earth Connections - the new era of coordinated solar-terrestrial research by scientists using Polar and other craft. Time TBD.
"There's a raging controversy over whether the magnetosphere stores energy to any degree, or just dissipates what the solar wind throws at it," said Dr. Tom Moore, director of the space plasma physics branch at SSL and principal investigator for TIDE.
Pictures from the UVI will help scientists decide whether the magnetosphere is driven directly by the solar wind, or it stores then discharges energy like a thunder cloud building a lightning charge.
"Northern winter traditionally has been the busy season for plasma scientists," said Dr. James Spann, a UVI co-investigator at SSL, "because that's when the aurora borealis is almost all in the night sky and can be viewed in visible as well as ultraviolet light."
UVI, included in three sessions at AGU, extends the busy season by letting scientists see what happens during the day. Doing this has been a challenge because the atmosphere's ozone layer reflects solar ultraviolet light that blinds most sensors. Previous instruments let scientists see parts of the daytime aurora, or the entire nightside auora. UVI aboard Polar is the first to show all of both day and nightside auroras. It does this with narrow bandpass filters - filters that admit narrowly define colors - that match lights emitted by the auroras.
UVI lets scientists measure, with precision, the energies flowing into the auroral oval. In addition to striking pictures, UVI reveals the footprint of the Earth's magnetic field lines that may stretch into deep space to several times the distance from Earth to Moon.
December 13, 1996
Fountains of electrified gases spewing from the Earth into space and pictures of the aurora during the day will be highlighted by the American Geophysical Union (AGU) annual winter conference in San Francisco Dec. 15-19.
AGU is one of the largest scientific bodies in the world and takes in everything from earthquakes to solar flares - including work by scientists at Marshall Space Flight Center's Space Sciences Laboratory (SSL) to understand what drives the aurora borealis and causes space storms that can black out cities.
At at three sessions during the AGU meeting, Marshall scientists will present their results in several papers, written with colleagues from other institutions, from the Thermal Ion Dynamics Experiment (TIDE) and the Ultraviolet Imager (UVI), two of several instruments aboard the Polar spacecraft launched in 1996.
TIDE recently confirmed that plasmas in the tail of the magnetosphere come from Earth's outer atmosphere being warmed by a flow of materials from space. The magnetosphere is formed by the Earth's magnetic field and buffers the planet from the constant wind of gases streaming from the sun.
Press briefings scheduled for the AGU Fall Meeting include:
Imaging Space Plasmas - Polar UVI and the Inner Magnetosphere Imager on which MSFC will have an important camera. Tuesday, Dec. 17, 12:45 p.m.
Sun-Earth Connections - the new era of coordinated solar-terrestrial research by scientists using Polar and other craft. Time TBD.
"There's a raging controversy over whether the magnetosphere stores energy to any degree, or just dissipates what the solar wind throws at it," said Dr. Tom Moore, director of the space plasma physics branch at SSL and principal investigator for TIDE.
Pictures from the UVI will help scientists decide whether the magnetosphere is driven directly by the solar wind, or it stores then discharges energy like a thunder cloud building a lightning charge.
"Northern winter traditionally has been the busy season for plasma scientists," said Dr. James Spann, a UVI co-investigator at SSL, "because that's when the aurora borealis is almost all in the night sky and can be viewed in visible as well as ultraviolet light."
UVI, included in three sessions at AGU, extends the busy season by letting scientists see what happens during the day. Doing this has been a challenge because the atmosphere's ozone layer reflects solar ultraviolet light that blinds most sensors. Previous instruments let scientists see parts of the daytime aurora, or the entire nightside auora. UVI aboard Polar is the first to show all of both day and nightside auroras. It does this with narrow bandpass filters - filters that admit narrowly define colors - that match lights emitted by the auroras.
UVI lets scientists measure, with precision, the energies flowing into the auroral oval. In addition to striking pictures, UVI reveals the footprint of the Earth's magnetic field lines that may stretch into deep space to several times the distance from Earth to Moon.
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