 
| February 2, 1999 Magnetic fields are found in many different locals throughout the universe. The Earth's field on this scale is a modest 0.6 Gauss. Some sun spot fields can be as strong as 5,000 Gauss, but for the most powerful fields, you need to visit distant neutron stars which tip the magnetic scales at over 1 trillion Gauss! Physicists have long been curious to study how matter behaves in the presence of intense magnetic fields, so in recent decades that have tried to create the most powerful fields possible under controlled laboratory conditions. An article in Physics Today magazine (October, 1996) describes Los Alamos National Laboratory experiments where explosively compressing magnetic materials to very small volumes produces fields as strong as 10 million Gauss (1000 Tesslas). These fields, however, can only be created for a few millionths of a second in a region a few millimeters across. Nature still has the monopoly on being able to create powerful fields lasting millions of years! |
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| February 1, 1999 The star 18 Scorpii has been identified by astronomer Gustavo Porto de Mello of the Federal University in Rio de Janeiro, as a near-twin to our own Sun. At a distance of 46 light years, this G-type star produces only 5% more light than our Sun, and is only slightly older. Also, its mass, temperature, chemical composition, color, surface gravity and rotation velocity are also virtually identical to the Sun's. Previously, Alpha Centauri was the nearest solar twin but it produces 52 % more light than the Sun, and has 60% more iron in composition. Studies of solar twins, for which nearly a dozen are known, provide a critical means of comparing just how typical our Sun is in its evolution and most importantly its surface activity. Both of these factors play an important role in modifying terrestrial climate, but without other sunlike stars to study, it has been difficult to assess just how typical the current conditions are. Also, isolated solar twins would be prime candidates for extensive searches for planetary systems more nearly like our own...and perhaps searches for life as well! |
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| January 28, 1999 One of the key ingredients long predicted by modern theories of the Sun's magnetic field is that it is generated within or below the convecting regions of the Sun, just below its surface. In a recent conference on 'Magnetic Helicity in Space and Laboratory Plasmas' reported in the American Geophysical Union's EOS newsletter on January 12, physicists discussed how measurements of solar magnetic helicity or 'twist' reveals has begun to confirm at least some of these theoretical expectations. Helioseismology, a technique which can probe the deep interior of the Sun, has revealed a boundary between the convecting regions and the deeper 'radiative' regions. Magnetic fields generated there should still have the imprint in them of the cyclonic twisting motions present in the streaming flows of plasma in this boundary layer as the gases make their way to the surface. As long ago as the 1950's Physicist Eugene Parker predicted that 'cyclonic convection' is one of the key ingredients responsible for generating the magnetic field of the Sun. By studying the twistiness of 'helicity' of the Sun's magnetic field, the details of how this process works may at long last be coming to light. |
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| January 22, 1999 A NASA sounding rocket designed to study aurora blasted off from the Andoya rocket range in Norway on January 20. The Cleft Accelerated Plasma Experiment Rocket (CAPER) carried an experiment package to altitudes of 1360 kilometers, carrying them through several auroral arcs and regions where electrons are being accelerated by powerful electric fields. Of particular interest was its passage through the 'Cleft Polar Fountain' region where atoms of oxygen and nitrogen from our atmosphere are being 'pumped' by solar activity into the magnetosphere. Scientists are still not sure of exactly what energy source or sources are driving the fountain. It is hoped that by studying the 20 minutes worth of data from CAPER that some new clues will emerge to solve this mystery. More information about this can be found at the NASA Space News page for January 7, 1999. |
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| January 21, 1999 More Good News! Thanks to the fact that Jupiter and Saturn orbit so far from the Sun, our Sun does not suffer from 'superflares' the way that other sun-like stars seem to. Yale University astronomer Bradley Schafer announced their findings at the American Astronomical Society January convention based on studies of so-called superflaring stars. These stars occasionally produce monster flares up to 10 million times more deadly than any flares produced by the Sun in the last 100 years. These flares are similar to what astronomers have long-detected in certain binary star systems, however, nine sun-like stars studied by the Yale team had no other stellar companions. Their conclusion is that these lone stars may have Jupiter-sized planets with similar magnetic fields orbiting near them, and that superflares are triggered by the interaction of the planetary and stellar magnetic fields. Schafer now advocates searching for isolated Sun-like, superflaring stars as prime candidates for identifying new planets similar in size to Jupiter. They also propose that the reason why the Sun does not produce superflares is that Jupiter and Saturn are just too far away from the Sun to trigger the process. Detailed computer modeling is now in progress to track down exactly how superflares are produced. |
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| January 10, 1999 Good News and Bad News. First, the Deep Space 1 mission with its futuristic ion space engine has been a resounding success. After 300+ hours of continuous operation the spacecraft's speed has been increased an additional 500 km/hour using only 2.5 kilograms of xenon fuel. NASA now considers this engine flight-qualified, and ready to be used on any future deep space missions that can benefit from its unique capabilities. At the same time DS1 is breaking records by using its fuel frugally, the SOHO solar observatory has fallen upon hard times again. Following what was to be a routine 'momentum-management' maneuver on December 21, SOHO's last working gyroscope failed. Since then, NASA has maintained contact with this $1.3 billion spacecraft by placing it in a temporary pointing mode that consumes 7 kilograms of fuel each day. With a reserve of only 180 kilograms, SOHO may run out of fuel for maintaining its orbit within 25 weeks. Engineers are working on several contingency plans including a 'reaction motor wheels mode' that should substantially improve SOHO's chances of lasting through the year. Meanwhile, in a race against time, it continues to return scientific data of the solar surface as the Sun continues its ascent to its most active years in the current sunspot cycle. |
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