Voyager 2 sends back surprising findings about solar system’s edgeDecember 11th, 2007 - 2:49 pm ICT by admin
Washington, Dec 11 (ANI): Surprising revelations about the boundary zone that marks the edge of the sun’s influence in space, have turned up by the MIT Plasma Science instrument of the Voyager 2 spacecraft.
The new discoveries were made when the spacecraft traversed the termination shockwave, formed when the flow of particles constantly streaming out from the sun-the solar wind-slams into the surrounding thin gas that fills the space between stars.
The Plasma Science instrument detected the boundary, as well as making detailed measurements of the solar wind’s temperature, speed and density as the spacecraft crossed through it.
The first finding with the help of the instrument is an unexpectedly strong magnetic field in the boundary zone, generated by currents in that incredibly tenuous gas in the region. This magnetic field squashes the bubble of outflowing gas from the sun, distorting it from the uniform spherical shape space physicists had expected to find.
The second finding is that just outside that boundary, the temperature, although hotter than inside, was ten times cooler than expected.
After scrambling for an answer to the unanticipated chilling effect, theorists said that the unexpected coolness, is caused by energy going into particles that are hotter than those that can be measured by the MIT plasma instrument.
The Voyager 2 is now passing through a boundary zone called the heliosheath, a region where the solar wind interacts with the surrounding interstellar medium.
But sometime in the next decade, it will cross a final edge, called the heliopause, where the sun’s outflow of particles ends. At that point, it will be able to measure characteristics of the interstellar medium, for the first time, in a region unaffected by the solar wind and the sun’s magnetism.
The Voyager 1 and 2 spacecraft were designed primarily to study the planets Jupiter and Saturn and their moons. After launch, Voyager 2’s path was adjusted to take it past Uranus and Neptune as well. Although the craft were only built for a five-year mission, both are still working well three decades later. (ANI)
Tags: boundary zone, chilling effect, edge of the sun, final edge, heliopause, heliosheath, interstellar medium, new discoveries, plasma science, science instrument, shape space, solar wind, space between stars, space physicists, spherical shape, tenuous gas, thin gas, voyager 1 and 2, voyager 2 spacecraft, wind and the sun