Voyager 1 Reaches 'magnetic Highway,' Gets A Taste Of Interstellar Spa

[Spartan]

[img]http://www.blogcdn.com/www.engadget.com/media/2012/12/voyager1entersdeeperspacejt.jpg[/img]


We're trying, with all our might, to avoid mention of final frontiers. Really we are. But, [url="http://www.engadget.com/tag/nasa/"]NASA[/url]'s [url="http://www.engadget.com/tag/voyager/"]Voyager 1[/url] is at the last point before crossing one. Currently the spacecraft is passing through what scientists are calling a "magnetic highway." This region is where the sun's magnetic field lines connect out to interstellar ones, which allows charged particles from our heliosphere (a surrounding cloud of charged particles encasing the sun) to pass out, while higher-energy particles from outside stream in. This area is still considered inside our solar bubble -- due to the lack of change in the direction of magnetic field lines -- but thanks to the ingress of external particles, it does give NASA a taste of conditions in deeper areas of the galaxy. Likewise, the agency believes this is the final... stage before reaching interstellar space, which it's estimated Voyager 1 will encounter in anything from a few months, to a couple of years' time.

[Spartan]

[img]http://www.nasa.gov/images/content/709981main_pia16483-946.gif[/img]


[b] Plasma Flow Near Voyager 1[/b]

This artist's concept shows plasma flows around NASA's Voyager 1 spacecraft as it approaches interstellar space. Voyager 1's low-energy charged particle instrument detects the speed of the wind of plasma, or hot ionized gas, streaming off the sun. It detected the slowing of this wind, also known as the solar wind, to zero outward velocity in a region called the stagnation region. Scientists had expected that the solar wind would turn the corner as it felt the pressure of the interstellar magnetic field and the interstellar wind flow. But that has not happened so far, so it is not clear what should be expected once the spacecraft reaches interstellar space.

Voyager 1 crossed a shockwave known as the termination shock in 2004. At the termination shock, the solar wind slows down abruptly from supersonic speeds. The heliopause is the boundary between the bubble of charged particles around our sun - known as the heliosphere - and interstellar space. Its location is still a mystery.

[Spartan]

[img]http://www.nasa.gov/images/content/709939main_Burlaga-1pia16485-43_946-710.jpg[/img]


S
[b] olar and Interstellar Magnetic Fields[/b]

This artist's concept shows the different expected directions of the magnetic fields in interstellar space (black lines) and the magnetic field emanating from our sun (white lines). NASA's Voyager 1 spacecraft is traveling northward out of the heliosphere, which is the bubble of charged particles the sun blows around itself. Voyager 2 is traveling southward out of the heliosphere.

Magnetic field lines spiral out from the sun as it rotates. The direction of the magnetic fields lines is believed to be a key indicator of arriving in interstellar space because scientists expect they hit our heliosphere at an angle. Interstellar space is dominated by the explosions of stars millions of years ago, so scientists don't expect the magnetic field lines there will be similar to our sun's. Where Voyager 1 is now, at the edge of our heliosphere, the lines basically run east-to-west, or perpendicular to the spacecraft's direction of travel.

The magnetic field lines pile up in the southern part of our heliosphere, as indicated by the compression of the black lines. They exert more pressure on that part of our heliosphere, giving the heliosphere's nose an uneven shape.

[Spartan]

[img]http://www.nasa.gov/images/content/710012main_pia16484-946.jpg[/img]

[b] Location of Low-Energy Charged Particle Instrument[/b]

This graphic shows the NASA's Voyager 1 spacecraft and the location of its low-energy charged particle instrument. A labeled close-up of the low-energy charged particle instrument appears as the inset image.

The instrument includes a stepper motor that turns the platform on which the sensors are mounted, so that the field of view rotates through 360 degrees. This motor was tested for 500,000 steps, enough to reach the orbit of Saturn, and has now completed over 6 million steps. The old-fashioned capacitor bank underneath the motor stores energy needed to provide a 15.7-watt pulse every 192 seconds.

[Spartan]

[img]http://www.nasa.gov/images/content/524723main_pia13892-43_946-710.jpg[/img]

[b] Voyagers in the Heliosheath[/b]

This artist's concept shows NASA's two Voyager spacecraft exploring a turbulent region of space known as the heliosheath, the outer shell of the bubble of charged particles around our sun. After more than 33 years of travel, the two Voyager spacecraft will soon reach interstellar space, which is the space between stars.

Our sun gives off a stream of charged particles that form a bubble around our solar system known as the heliosphere. The solar wind travels at supersonic speeds until it crosses a shockwave called the termination shock. That part of our solar system is shown in dark blue. Voyager 1 crossed the termination shock in December 2004 and Voyager 2 did so in August 2007. Beyond the termination shock is the heliosheath, shown in gray, where the solar wind dramatically slows down and heats up. Outside those two areas is territory dominated by the interstellar wind, which is blowing from the left in this image. As the interstellar wind approaches the heliosphere, a bow shock forms, indicated by the bright arc.

The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both spacecraft. JPL is a division of the California Institute of Technology in Pasadena. The Voyager missions are a part of the NASA Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate.

[maheshbabuy]

[url=http://www.desigifs.com/gifs/791/venkatesh][img]http://www.desigifs.com/sites/default/files/venky3.gif[/img][/url]