Posted on 11/21/2001 7:13:08 AM PST by blam
Mystery gas keeps heading for Sun
A space probe has spotted mysterious clouds of gas falling towards the surface of the Sun.
The gas battles forward despite facing a solar wind which reaches speeds of 74 miles per second.
Astronomers believe the clouds are pulled towards the Sun by changes in its magnetic field.
The inflows can start at altitudes of up to 1.7 million miles from the surface and the latest pictures have surprised scientists.
Bernhard Fleck, the European Space Agency's project scientist for the Soho probe mission, says: "I was stunned when I saw the first movies showing these inflows.
"Before this discovery by Soho no one had any idea that gas could travel the wrong way, and be pushed back towards the Sun."
The images were processed by Neil Sheeley and Yi-Ming Wang at the US naval research laboratory.
If they are right, and the pictures show collapsing magnetic loops, pulling material against the solar wind, they will confirm that the Sun recycles the magnetic field in its atmosphere.
Story filed: 11:00 Wednesday 21st November 2001
I'm guessing that the "mystery gas" is the infamous "Pugsley F@rt" heading for its final resting place. Expect serious solar flares for the next year as its effects are smfelt.
Source: Los Alamos National Lab
Date: Posted 9/29/1998Three Spacecraft Reveal Unexplained Motion
LOS ALAMOS, N.M., Sept. 24, 1998 -- A team of planetary scientists and physicists has identified a tiny, unexplained sunward acceleration in the motions of the Pioneer 10, Pioneer 11 and Ulysses spacecraft. The anomalous acceleration -- about 10 billion times smaller than the acceleration we feel from Earth's gravitational pull -- was identified after detailed analyses of radio data from the spacecraft.
The research team, led by John Anderson of NASA's Jet Propulsion Laboratory and including Michael Nieto of The Department of Energy's Los Alamos National Laboratory, considered and ruled out many possible causes for the perturbation in the spacecrafts' motions. The team expects the explanation, when found, will involve conventional physics and understanding, but the team has also considered what implication the anomalous motion has for some new physical effect.
The accelerations are so persistent that they could be pointing to some relevant physics that's been overlooked in trying to explain the motions of bodies in the universe.
The research has been accepted for publication in Physical Review Letters.
"In order of decreasing probability the possible causes are some systematic effect associated with the spacecraft; some subtle effect associated with our tracking systems, which would be important to know for space navigation; or some manifestation of 'new physics,' " Nieto said. "By looking at the third possibility we can examine how well 'normal' physics works, which in itself gives you further insight into the universe.
The researchers analyzed signals sent from Earth that were actively reflected by a transponder on the spacecraft. The resulting Doppler shift in the signal was used to calculate the motions. NASA's Deep Space Network sent and received the signals.
Pioneer 10 was officially tracked until March 1997, when it was some six billion miles away from the sun. (Pioneer 10 is still transmitting, and occasional additional radio Doppler data is provided to the research team.)
Pioneer 11, due to a radio failure, last sent useful radio Doppler transmissions in October 1990, when it was less than three billion miles from the sun. Ulysses has been tracked on its looping flight out of the ecliptic and around the sun's poles.
The researchers also examined Galileo data from that craft's journey from Earth to Jupiter.
Measurements of both Pioneer craft and Ulysses gave approximately the same answer for the strength of the anomalous acceleration. Galileo, too, yielded a similar value, but its flight was so close to the sun the researchers could not rule out the effects of solar radiation pressure.
Newton's laws of gravity alone -- with the sun providing the dominant gravitational force -- are good enough for NASA to send spacecraft on planetary rendezvous with near-pinpoint precision. But the anomalous motions of these spacecraft are so small that the researchers had to consider numerous possible causes: perturbations from the gravitational attraction of planets and smaller bodies in the solar system; radiation pressure, the tiny transfer of momentum when photons impact the spacecraft; general relativity; interactions between the solar wind and the spacecraft; possible corruption to the radio Doppler data; wobbles and other changes in Earth's rotation; outgassing or thermal radiation from the spacecraft; and several others.
The researchers have so far not found that any of these effects can account for the size and direction of the anomalous acceleration.
After exhausting the list of possible "normal" explanations, the researchers looked at possible modifications to the attractive force of gravity or the possible influence or non-ordinary matter, or "dark" matter.
The dark matter explanation didn't hold up because so much matter would have been required to create the measured spacecraft acceleration it would have affected motions of other bodies in the solar system.
Looking at other mathematical representations for gravitational interactions also "come up against a hard experimental wall," the researchers wrote: namely that the gravitational effect would also be seen in planetary motions, especially for Earth and Mars "If the anomalous radial acceleration acting on spinning spacecraft is gravitational in origin, it is not universal," the researchers concluded. It would have to affect bodies massing a thousand kilograms or so more than bodies the size of planets.
Nieto has long been interested in the possibility that gravity works differently on antimatter than on the familiar matter that makes up our everyday world. This led him to consider how well we understand gravity's influence on normal matter and whether studies of the motions of comets or spacecraft could be used to identify any deviations from the expected influence of gravity.
Meanwhile, John Anderson and his JPL colleagues had for years puzzled over "residual errors" between the calculated and measured positions of the Pioneer spacecraft. Anderson first saw the effect in 1980, but until he had accumulated data over the next 15 years, he could easily dismiss it as systematic errors. "Like a lot of problems in astronomy, many years of observation are needed," Anderson said.
After Anderson and Nieto hooked up the group redoubled its efforts to analyze the spacecraft motions and possible contributing perturbations. An independent analysis of the motions using a computer program developed by The Aerospace Corp. ruled out errors in JPL's orbital determination software as the source of the anomalous acceleration.
The researchers noted that NASA's planned mission to Pluto, which would include more accurate tracking systems, will provide additional, high- quality data for investigating this mystery. In addition, Pioneer 10 is still a potential source of data, since its transmitter is still functioning. The team also is conducting more detailed analyses of Ulysses' swing around the sun.
"Clearly, more analysis, observation, and theoretical work are called for," the researchers concluded.
Other authors on the PRL paper were Philip Laing of The Aerospace Corp., Anthony Liu of Astrodynamic Sciences, and Eunice Lau and Slava Turyshev of JPL.
It just goes to show you, "It's always something." This new discovery may explain the unknow cause of their 'drift'.
Mysterious clouds of gas falling towards the Sun have been spotted with the Solar and Heliospheric Observatory (SOHO) spacecraft. They go against the fast-moving streams of gas that pour out continuously into space in the solar wind.
In today's issue of Astrophysical Journal Letters, the scientists who found them suggest that the inflows are due to frequent local adjustments to the Sun's magnetic field. The discovery promises a better understanding of the sources of the solar magnetism that envelops the Earth, quarrels with our own planet's field, and to some extent protects us from cosmic rays coming from the stars.
For many years astronomers have watched glowing fountains and arches rise and fall in the Sun's lower atmosphere. The gas clouds now seen begin their descent from far out in the atmosphere. They were first noticed in 1997, in images from the Large Angle and Spectrometric Coronagraph (LASCO) instrument on SOHO. Similar inflows then turned up in re-examined images going back to early in 1996, soon after SOHO's launch, and many others have occurred since.
About 8,000 inflow events have now been logged -- most of them since 1998 while the Sun has been at its most active, as judged by the high count of sunspots. The inflows can start at an altitude of up to 1,700,000 miles (2,700,000 kilometres) above the visible surface, a distance equal to twice the Sun's diameter. Here the accelerating solar wind, leaving the Sun, has reached a speed of about 75 miles per second (120 kilometres per second). Fighting against it, the gas clouds travel in at 31 to 62 miles per second (50-100 kilometres per second). Typically they appear to come to rest about 435,000 miles (700,000 kilometres) out.
"For decades, we've been able to observe cooler gas rising and then falling, under the influence of gravity, lower down in the solar atmosphere," notes Dr. Joe Gurman, NASA's project scientist for SOHO. "Until now, though, the hotter, electrically charged gas higher in the Sun's outer atmosphere, the corona, has only been seen flowing up and away. Now we have to figure out how these downflows relate to the evolution of the magnetic fields that are responsible for both the normal outflow the solar wind and for the violent processes we call space weather."
The LASCO instrument on board SOHO blots out the intense direct light from the Sun's visible surface, to keep the Sun permanently in eclipse so its much fainter outer atmosphere can be seen. Even with this powerful instrument, the inflows are hard to see. Most useful for the purpose is the LASCO C2 component, which shows the region from 435,000 to 2,175,000 miles (700,000 to 3,500,000 kilometres) from the visible surface.
At the Naval Research Laboratory, Dr. Neil Sheeley and Dr. Yi-Ming Wang find the inflows by subtracting one electronic image from the next, taken 20-25 minutes later, and assembling a series of such difference images into a movie. The human eye is then good at spotting unusual, inward movement against the general background of outflowing gas.
Although the gas feels a very strong pull from the Sun's gravity, this is not the decisive force acting on the inflows. The high rate at which they gather speed initially, and their eventual slowdown, suggest instead that they are firmly under the control of a magnetic force. A few inflows are a backwash from explosive mass ejections, which are sporadic events, but the overwhelming majority occur quite regularly within regions of slow solar wind.
A downpour of 20 inflows per day, seen on the left side of the Sun, can be followed after a lull of two weeks by a similar downpour seen on the right side. This means that the occurrences persist in a particular region on the Sun, which takes two weeks to move from left to right as the Sun rotates. The regional association can continue for months, and suggests to Sheeley and Wang how the inflow regions and the magnetic field are related.
Near the Sun's surface the magnetic field is a patchwork, with field lines looping outwards from some places and back in at others. The solar wind drags the longest loops far out into space, creating contrasting sectors where the magnetic field lines are directed in opposite ways (polarities). Before the solar wind has reached its full speed, opposing field lines can short-circuit at a boundary between sectors to form new magnetic loops. These collapse towards the Sun, carrying with them the inflowing gas clouds now observed.
"We are seeing something opposite to what we expected," says Sheeley. "Normally, when this happens, we initially doubt the observation -- suspecting, for example, that the movie is running backwards. But when we confirm that the observation is really correct, we are forced to change our way of thinking. Such mind-changing discoveries help us past temporary snags in our understanding and inevitably lead to progress."
In this case, one area of progress may concern magnetic fields and their effects on Earth. If Sheeley and Wang are right in thinking that the inflows indicate collapsing magnetic loops, pulling material inwards against the outward drag of the solar wind, then these are showing us how the Sun recycles the magnetic field in its atmosphere. This recycling process regulates the strength of the interplanetary magnetic field that extends outward past Earth and affects space weather.
SOHO's inflows thus provide unexpected clues to what influences solar magnetic activity near the Earth and all across the Solar System. Apart from magnetic storms, which can harm technical systems, there is growing interest in the shield that the interplanetary magnetic field provides against cosmic rays. These energetic particles from the Galaxy can cause genetic mutations in living things and glitches in computers, and some scientists think they are also involved in cloud formation on the Earth. But their variations have puzzling features.
Reductions and increases in cosmic rays reaching the Earth are not in perfect step with rising and falling sunspot activity. And when sunspot cycles were of longer duration, 100 years ago, the interplanetary magnetic field was weaker and the cosmic-ray intensity was on average higher than nowadays. The 'mind-changing' discovery of the inflows near the Sun may lead to better explanations of these variations, and eventually to predictions of cosmic-ray intensities.
SOHO is a project of international cooperation between the European Space Agency and NASA. The spacecraft was built in Europe for ESA and equipped with instruments by teams of scientists in Europe and the USA. NASA launched SOHO in December 1995, and in 1998 ESA and NASA decided to extend its highly successful operations until 2003.
A multinational scientific team that includes the US Naval Research Laboratory, France's Laboratoire d'Astronomie Spatiale, Germany's Max Planck-Institut für Aeronomie, and the UK's Birmingham University, contributed LASCO to SOHO.
LASCO is already famous for registering explosive mass ejections from the Sun, and discovering many sungrazing comets.
Super-Kamiokande Neutrino telescope Heavily Damaged by Accident
A scientific tragedy.
A temporary setback. They'll get it fixed and resume operations. These detectors are probably not the cheap kind you get at K-Mart.
Yup. I saw this but could not bring myself to post it. Thanks.
It is probably just the result of airing out the White House 11 months ago, anyway - it takes a little while for these things to get that far.
I thought that we had already decided that it didn't. Gravitational lensing?
Be patient, the aether theory will return. It will have some enhancements to bring it into correspondence with relativity and newer discoveries.
If we put a bag around the sun and collected all of the photons until the sun was burned out would the bag weigh as much as the sun when it was brand-new?
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