Voyager Crosses Point Of Solar tranquility
The 33 year odyssey of NASA's Voyager 1 spacecraft has reach a distant point at the border of our solar system where there is no external motion of solar wind. Now hurtling toward interstellar space a few 17.4 billion kilometers (10.8 billion miles) from the Sun, Voyager 1 has cross into an region where the velocity of the hot ionized gas, or plasma, emanate straight outward from the Sun has slowed to zero. Scientists think the solar wind has been turned sideways by the force from the interstellar wind in the district between stars. The event is a major milestone in Voyager 1's way through the heliosheath, the turbulent external shell of the Sun's sphere of influence, and the spacecraft's future leaving from our solar system.

"The solar wind has turned the corner," said Ed Stone, Voyager plan scientist based at the California Institute of Technology in Pasadena, Calif. "Voyager 1 is receiving close to interstellar space." Our sun gives off a stream of emotional particles that form a bubble recognized as the heliosphere around our solar system. The solar wind movements at supersonic speed awaiting it crosses a shockwave called the termination shock. At this point, the solar wind radically slows down and heats up in the heliosheath. Launched on Sept. 5, 1977, Voyager 1 crossed the extinction shock in December 2004 into the heliosheath. Scientists have use information from Voyager 1's Low-Energy.

Charged Particle Instrument to assume the solar wind's velocity. When the speed of the charge particles drumming the external face of Voyager 1 matched the spacecraft's speed, researchers know that the net external speed of the solar wind was zero. This happened in June, when Voyager 1 was about 17 billion kilometers from the Sun. Because the velocity can fluctuate, scientists watch four more monthly reading before they were persuaded the solar wind's outward speed really had slowed to zero. Analysis of the data shows the velocity of the solar wind has progressively slowed at a speed of about 20 kilometers per second each year since August 2007, when the solar wind was speeding external at about 60 kilometers per second. The external speed has remain at zero since June.

No comments:

Post a Comment