Image Credit: NASA/JPL-Caltech
It may be some 10.8 billion miles from home, but Voyager 1 is sending back some surprising data from the edge Even more recent transmissions show the gallant probe is closer to interstellar space than ever. “We’ve reached the boundary of the heliosheath, Jim… and it ain’t dead.”
It has taken 34 years, but Voyager 1 has now defiantly encountered the edge – the area where the speed of the solar plasma has decreased from 150,000 miles an hour down to zero. As released in the June 16th issue of Nature, a team of Voyager scientists led by Stamatios Krimigis of the Johns Hopkins University Applied Physics Laboratory speculates “the outflow of the solar wind may have stopped because of the pressure from the interstellar magnetic field in the region between stars.”
For the last three years the incredible little probe has been busy overseeing the predominant part of the plasma’s velocity in the heliosheath – a virtual pool of energetic ions and electrons. Now measurements have slipped from 40 miles per second to zero. This was first noted in April when Voyager’s speed matched the assessments.
“This tells us that Voyager 1 may be close to the heliopause, or the boundary at which the interstellar medium basically stops the outflow of solar wind,” says Krimigis, principal investigator for Voyager’s Low-Energy Charged Particle instrument. “The extended transition layer of near-zero outflow contradicts theories that predict a sharp transition to the interstellar flow at the heliopause – and means, once again, we will need to rework our models.”
Because we’re literally breaking new science ground, these new findings on velocities could fluctuate – meaning that more monthly readings are in order. When will we know? A good indicator would be when hot particles turn cold… a signal that interstellar space has been breached. This could occur as soon as the end of 2012.
Just another reason we might be around just a little bit longer…
