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creedo299
Epochal Historian
http://www.sciencedaily.com/releases/2004/09/040906083929.htm
The Sun's X-file Under The Spotlight
One of the Sun's greatest mysteries is about to be unravelled by UK solar astrophysicists hosting a major international workshop at the University of St Andrews from September 6-9th 2004. For years scientists have been baffled by the 'coronal heating problem': why it is that the light surface of the Sun (and all other solar-like stars) has a temperature of about 6000 degrees Celsius, yet the corona (the crown of light we see around the moon at a total eclipse) is at a temperature of two million degrees?
The TRACE satellite takes a close-up image of a magnetic active region at the limb of the Sun - the bright arches are due to the Sun's strong magnetic field channelling the hot, million degree ionised gases. The Transition Region and Coronal Explorer is a mission of the Stanford-Lockheed Institute for Space Research and is a NASA Small Explorer Mission. (Credit: NASA Trace Mission)
What's Related
"Beyond the Blue Horizon" -- A Total Solar Eclipse Chase
Fountains Of Fire Illuminate Solar Mystery
Montana And European Scientists Take Sun's Temperature
> more related stories
--------------------------------------------------------------------------------
Related section: Space & Time
Understanding our nearest star is important because its behaviour has such an immense impact on our planet. This star provides all the light, heat and energy required for life on Earth and yet there is still much about the Sun that is shrouded in mystery.
"The problem is like an Astrophysics X-file! It is totally counter intuitive that the Sun's temperature should rise as you move away from the hot surface," explains Dr Robert Walsh of the University of Central Lancashire and co-organiser of the workshop. "It is like walking away from a fire and suddenly hitting a hotspot, thousands of times hotter than the fire itself."
Using the joint ESA/NASA satellite, the Solar and Heliospheric Observatory (SOHO), along with another NASA mission called TRACE, researchers have gathered enough data to form two rival theories to explain what has been termed 'coronal heating'. It is now believed that the Sun's strong magnetic field is the culprit behind this unique phenomenon. At this SOHO workshop, scientists from the UK and around the world will look at the evidence for these two explanations and try to untangle the clues we now have available to us.
Walsh continues, "SOHO's contribution to the research has been so important because for the first time we can take simultaneous magnetic and extreme ultraviolet images of the Sun's atmosphere, allowing us to study the changes in the magnetic field at the same time as the corresponding effect in the corona. Then, using sophisticated computer simulations, we have constructed 3d models of the coronal magnetic field that can be compared with SOHO's observations."
One possible mechanism for coronal heating is called 'wave heating'. Prof Alan Hood from the Solar and Magnetospheric Theory Group at St. Andrews explains: "The Sun has a very strong magnetic field which can carry waves upwards from the bubbling solar surface. Then these waves dump their energy in the corona, like ordinary ocean waves crashing on a beach. The energy of the wave has to go somewhere and in the corona it heats the electrified gases to incredible temperatures."
The other rival mechanism is dependent on twisting the Sun's magnetic field beyond breaking point. Prof Richard Harrison of the UK's Rutherford Appleton Laboratory says "The Sun's magnetic field has loops, known to be involved in the processes of sun spots and solar flares. These loops reach out into the Sun's corona and can become twisted. Like a rubber band, they can become so twisted that eventually they snap. When that happens, they release their energy explosively, heating the coronal gases very rapidly".
The Sun is the only star astronomers can study in close detail and many questions remain. The workshop will also look forwards to future missions such as Solar-B, STEREO and Solar Orbiter that all have important UK involvement through PPARC.
The Sun's X-file Under The Spotlight
One of the Sun's greatest mysteries is about to be unravelled by UK solar astrophysicists hosting a major international workshop at the University of St Andrews from September 6-9th 2004. For years scientists have been baffled by the 'coronal heating problem': why it is that the light surface of the Sun (and all other solar-like stars) has a temperature of about 6000 degrees Celsius, yet the corona (the crown of light we see around the moon at a total eclipse) is at a temperature of two million degrees?
The TRACE satellite takes a close-up image of a magnetic active region at the limb of the Sun - the bright arches are due to the Sun's strong magnetic field channelling the hot, million degree ionised gases. The Transition Region and Coronal Explorer is a mission of the Stanford-Lockheed Institute for Space Research and is a NASA Small Explorer Mission. (Credit: NASA Trace Mission)
What's Related
"Beyond the Blue Horizon" -- A Total Solar Eclipse Chase
Fountains Of Fire Illuminate Solar Mystery
Montana And European Scientists Take Sun's Temperature
> more related stories
--------------------------------------------------------------------------------
Related section: Space & Time
Understanding our nearest star is important because its behaviour has such an immense impact on our planet. This star provides all the light, heat and energy required for life on Earth and yet there is still much about the Sun that is shrouded in mystery.
"The problem is like an Astrophysics X-file! It is totally counter intuitive that the Sun's temperature should rise as you move away from the hot surface," explains Dr Robert Walsh of the University of Central Lancashire and co-organiser of the workshop. "It is like walking away from a fire and suddenly hitting a hotspot, thousands of times hotter than the fire itself."
Using the joint ESA/NASA satellite, the Solar and Heliospheric Observatory (SOHO), along with another NASA mission called TRACE, researchers have gathered enough data to form two rival theories to explain what has been termed 'coronal heating'. It is now believed that the Sun's strong magnetic field is the culprit behind this unique phenomenon. At this SOHO workshop, scientists from the UK and around the world will look at the evidence for these two explanations and try to untangle the clues we now have available to us.
Walsh continues, "SOHO's contribution to the research has been so important because for the first time we can take simultaneous magnetic and extreme ultraviolet images of the Sun's atmosphere, allowing us to study the changes in the magnetic field at the same time as the corresponding effect in the corona. Then, using sophisticated computer simulations, we have constructed 3d models of the coronal magnetic field that can be compared with SOHO's observations."
One possible mechanism for coronal heating is called 'wave heating'. Prof Alan Hood from the Solar and Magnetospheric Theory Group at St. Andrews explains: "The Sun has a very strong magnetic field which can carry waves upwards from the bubbling solar surface. Then these waves dump their energy in the corona, like ordinary ocean waves crashing on a beach. The energy of the wave has to go somewhere and in the corona it heats the electrified gases to incredible temperatures."
The other rival mechanism is dependent on twisting the Sun's magnetic field beyond breaking point. Prof Richard Harrison of the UK's Rutherford Appleton Laboratory says "The Sun's magnetic field has loops, known to be involved in the processes of sun spots and solar flares. These loops reach out into the Sun's corona and can become twisted. Like a rubber band, they can become so twisted that eventually they snap. When that happens, they release their energy explosively, heating the coronal gases very rapidly".
The Sun is the only star astronomers can study in close detail and many questions remain. The workshop will also look forwards to future missions such as Solar-B, STEREO and Solar Orbiter that all have important UK involvement through PPARC.
stillblackpond
Temporal Novice
I've stood on stage, next to a wall of amplifiers in full jam mode, and was astonished that I could not only talk to the person next to me but I could hear a damn guitar pick land on the floor. Two rows away from the stage and I was wishing they would turn the music down. I figured, as a defense mechanism, the sound waves were simply too much for my organs to register but now it seems stranger than that. Is there a point that heat can reach where it becomes something else? Perhaps like space compressed portals deminsionally.
creedo299
Epochal Historian
From link>http://www.msnbc.msn.com/id/5942268/?GT1=5100
MSNBC staff and news service reports
Updated: 2:44 p.m. ET Sept. 8, 2004
DUGWAY PROVING GROUND, Utah - A space capsule holding what scientists hoped would be clues to the origin of the solar system fell to a crash landing on Earth Wednesday after its parachute failed to open.
A pair of helicopters helmed by stunt pilots had been ready to snatch the refrigerator-sized parachute with a hook as the Genesis capsule descended. But there was no sign that the parachute opened, and video from the scene showed the 452-pound (205-kilogram) capsule hurtling toward the ground at the military Utah Test and Training Range. The capsule broke open on impact.
The $260 million Genesis mission was bringing back to Earth a set of fragile disks containing billions of atoms collected from solar wind, the first cosmic samples to be returned to Earth from beyond the moon.
Now, the fate of those atoms is uncertain. NASA officials believed the disks would shatter even if the capsule hit the ground with a parachute.
“There was a big pit in my stomach,†said physicist Roger Wiens of Los Alamos National Laboratory, which designed the atom collector plates. “This just wasn’t supposed to happen. We’re going to have a lot of work picking up the pieces.â€
Studying solar system's origins
Together, the charged atoms captured over 884 days on the capsule’s disks of gold, sapphire, diamond and silicone are no bigger than a few grains of salt — but if the samples survived, that would be still be enough to help reconstruct the chemical origin of the sun and its family of planets, scientists said. They had hoped to study the material for at least five more years.
Wiens was confident they could retrieve the pieces, but said “it’s going to be a lot tougher to sort out the pieces of broken material.â€
The five disks were of different thicknesses, Wiens said, which could make it easier for scientists to sort out shattered remnants and put pieces back together like a puzzle.
It was not immediately clear how soon the retrieval process could be completed. NASA engineers feared the explosive meant to open the parachute might still be active.
“That presents a safety hazard to recovery crews,†said Chris Jones, solar system exploration director for NASA’s Jet Propulsion Laboratory.
Choreographed return to Earth
The Genesis probe was launched in 2001 and traveled in tandem with Earth, just outside the planet's magnetic shield, for three orbits of the sun. It started the return trip months ago, following a tightly choreographed scenario. As Earth's gravitational pull brought it closer, the capsule picked up speed rapidly, reaching velocities of 25,000 mph or 11 kilometers per second. The capsule's descent was then slowed by atmospheric re-entry.
That’s when the parachute and the helicopters were supposed to take over.
Both Cliff Fleming, the lead helicopter pilot, and backup pilot Dan Rudert had years of experience as Hollywood stunt pilots, and they replicated the retrieval in dozens of practice runs. But because the parachute never opened, they never had a chance to snag the capsule. Instead, the probe slammed into the Utah desert at an estimated speed of 193 mph (309 kilometers per hour), Jones said.
NASA was still debating what to do with the broken capsule. The original post-landing scenario called for the probe to be packed up and driven with a convoy of armed guards to Houston’s Johnson Space Center in a truck. If the samples survived, solar particles would be parceled out for analysis to the University of California at Los Angeles and the University of Chicago’s Argonne National Lab.
Looking back, looking ahead
The crash represented a public-relations setback for the space agency, which weathered the twin failures of Mars missions in 1999 and is still dealing with the aftermath of last year's loss of the shuttle Columbia and its crew. On the positive side of the ledger, NASA has scored triumphs in the past year with its twin Mars rover missions and the Cassini mission to Saturn.
Another NASA probe named Stardust is due to return to the Utah Test and Training Range in 2006, bearing samples of cosmic dust from a comet's wake. Stardust uses a similar parachute system to brake its descent. However, the Stardust capsule is designed to be cut loose from its parachute and survive impact.
This report includes information from The Associated Press and MSNBC's Alan Boyle
*All rights, MSNBC.com
MSNBC staff and news service reports
Updated: 2:44 p.m. ET Sept. 8, 2004
DUGWAY PROVING GROUND, Utah - A space capsule holding what scientists hoped would be clues to the origin of the solar system fell to a crash landing on Earth Wednesday after its parachute failed to open.
A pair of helicopters helmed by stunt pilots had been ready to snatch the refrigerator-sized parachute with a hook as the Genesis capsule descended. But there was no sign that the parachute opened, and video from the scene showed the 452-pound (205-kilogram) capsule hurtling toward the ground at the military Utah Test and Training Range. The capsule broke open on impact.
The $260 million Genesis mission was bringing back to Earth a set of fragile disks containing billions of atoms collected from solar wind, the first cosmic samples to be returned to Earth from beyond the moon.
Now, the fate of those atoms is uncertain. NASA officials believed the disks would shatter even if the capsule hit the ground with a parachute.
“There was a big pit in my stomach,†said physicist Roger Wiens of Los Alamos National Laboratory, which designed the atom collector plates. “This just wasn’t supposed to happen. We’re going to have a lot of work picking up the pieces.â€
Studying solar system's origins
Together, the charged atoms captured over 884 days on the capsule’s disks of gold, sapphire, diamond and silicone are no bigger than a few grains of salt — but if the samples survived, that would be still be enough to help reconstruct the chemical origin of the sun and its family of planets, scientists said. They had hoped to study the material for at least five more years.
Wiens was confident they could retrieve the pieces, but said “it’s going to be a lot tougher to sort out the pieces of broken material.â€
The five disks were of different thicknesses, Wiens said, which could make it easier for scientists to sort out shattered remnants and put pieces back together like a puzzle.
It was not immediately clear how soon the retrieval process could be completed. NASA engineers feared the explosive meant to open the parachute might still be active.
“That presents a safety hazard to recovery crews,†said Chris Jones, solar system exploration director for NASA’s Jet Propulsion Laboratory.
Choreographed return to Earth
The Genesis probe was launched in 2001 and traveled in tandem with Earth, just outside the planet's magnetic shield, for three orbits of the sun. It started the return trip months ago, following a tightly choreographed scenario. As Earth's gravitational pull brought it closer, the capsule picked up speed rapidly, reaching velocities of 25,000 mph or 11 kilometers per second. The capsule's descent was then slowed by atmospheric re-entry.
That’s when the parachute and the helicopters were supposed to take over.
Both Cliff Fleming, the lead helicopter pilot, and backup pilot Dan Rudert had years of experience as Hollywood stunt pilots, and they replicated the retrieval in dozens of practice runs. But because the parachute never opened, they never had a chance to snag the capsule. Instead, the probe slammed into the Utah desert at an estimated speed of 193 mph (309 kilometers per hour), Jones said.
NASA was still debating what to do with the broken capsule. The original post-landing scenario called for the probe to be packed up and driven with a convoy of armed guards to Houston’s Johnson Space Center in a truck. If the samples survived, solar particles would be parceled out for analysis to the University of California at Los Angeles and the University of Chicago’s Argonne National Lab.
Looking back, looking ahead
The crash represented a public-relations setback for the space agency, which weathered the twin failures of Mars missions in 1999 and is still dealing with the aftermath of last year's loss of the shuttle Columbia and its crew. On the positive side of the ledger, NASA has scored triumphs in the past year with its twin Mars rover missions and the Cassini mission to Saturn.
Another NASA probe named Stardust is due to return to the Utah Test and Training Range in 2006, bearing samples of cosmic dust from a comet's wake. Stardust uses a similar parachute system to brake its descent. However, the Stardust capsule is designed to be cut loose from its parachute and survive impact.
This report includes information from The Associated Press and MSNBC's Alan Boyle
*All rights, MSNBC.com