At last, Voyager 1 slips into interstellar space
Andrew Grant http://www.sciencenews.org/view/generic/id/353199/description/At_last_Voyager_1_slips_into_interstellar_space The Voyager 1 spacecraft has finally reached interstellar space. August 25 2012 Voyager was about 18.2 billion kilometers from the sun, or nearly 122 times as far from the sun as Earth. In 1977 The Voyager spacecraft had been launched. Originally it was only supposed to reach the outer planets gathering information and photos. But Edward stone and his team had hoped for more from the start.
The sun puts out a flood of hot, charged particles called plasma that jets out every which way. The plasma forms a bubble called the heliosphere that is tens of billions of kilometers in diameter. The amount of plasma surrounding The Voyager spacecraft had gone down recently making indicating that it had gone into interstellar space.
However, Stone and his team thought that was false. They didn’t have the information of what they thought would be the indicator that the Voyager spacecraft had passed interstellar space: a shift in the direction of the magnetic field. Solar plasma produces a special magnetic field because it all comes from the same place. Scientists thought that the magnetic field would shift in interstellar space, where particles fly about in all directions. Despite the evidence that Voyager had departed the heliosphere, the magnetic field direction remained constant making astronomers need another way to confirm it.
Both voyager spacecraft had sensors that could accurately measure plasma heat and density. But Voyager 1’s had broken somewhere by Saturn. Donald Gurnett found a way to get a good measurement anyway. Using other data, he discovered that in April 2013 a solar wave from the sun had reached Voyager’s neck of the woods and jostled electrons in the surrounding plasma. After…