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Voyager 1 Reaches Interstellar Space
letxa2000 writes "CNN is reporting that Voyager 1, now some 8.4 billion miles (90 AUs) from the sun, has left the solar system and entered interstellar space by reaching the heliopause. However, whether the probe has reached the heliopause or is just coming close is the subject of two papers to be published in Thursday's Nature Magazine. The probe supposedly has enough nuclear fuel to last until 2020. Will it be able to find anything interesting outside the solar system in the next 17 years?"
Detailed answer: Yes.
Questions that can still be investigated by Voyager include a number of questions about the interaction between the solar wind, solar magnetic field, and interstellar medium, direct measurements of the interstellar magnetic field, the actual composition of interstellar gas, where exactly the heliopause lies, and how it's affected by changes in solar activity. I'm sure there are even more questions that I haven't thought of.
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
That's how long it takes a signal to reach us from the probe. When you consider the galaxy is 100,000 light years across, 8.4 billion miles is nothing.
Voyager has been moving through space in ways unexplainable by physics. There is a small acceleration that can't be accounted for using known laws. It's almost like gravity doesn't work quite the way we think it does.
Of course, there is always the possibility that we just can't see the source of the acceleration, and it'll turn out to be something simple. However so far, all proposals put forth to explain it have been shown to be incorrect.
There is a deeper connection to very important issues in physics. For decades we have been studying the fabled "dark matter" which is supposed to be the cause of the anomalous rotation of the galaxy. The galaxy does not move in ways predicted by the laws of gravity. It is as if there is a huge amount of hidden mass which is influencing its rotation. So far we have not found any of this "dark matter."
But imagine the possibility. What if dark matter doesn't really exist? What if it's our understanding of gravity that is wrong? This would have profound implications throughout physics. After all our only direct experience of gravity is what happens here on Earth and within the bounds of the solar system. Except that today, we have a probe that has crossed that limit.
Perhaps the anomalous motion of Voyager will shed light on the situation. I for one would be utterly elated if it turns out we have to rewrite our physics books.
Voyager isn't useless yet!