Having two or more sets of data sources that contradict each other is the nightmare of every scientist. That situation is exactly where researchers who analyze data from NASA’s Voyager probes find themselves in as Voyager 2 stepped on interstellar space the prior year. The reach makes it the second spacecraft that has managed to get there.
Now, in multiple studies, researchers have tried to compare or contrast the information sent by the two Voyagers and attempt to understand why the data contradicts, knowing that they won’t get an additional source of data any time soon.
The Margins of the Solar System
Back in 2012, Voyager 1 passes through the transition zone, which is essentially the influences extended by the Sun’s gravitation and our own galaxy’s influence which met, at some point. When these two influences collide, the Sun’s impact gets weaker, and the galaxy’s influence monopolizes the place.
During that transition, the spacecraft registered a slight expansion of high-energy rays, but these were accented by two spikes where high-energy cosmic rays abruptly increased. These linked to two dips in the force of lower-energy charged particles coming from the Sun, implying that a part of the interstellar environment was pouring into the Solar System.
In all these cases, the solar impact retrieves as cosmic rays went back to normal, and solar particles returned to their usual levels. Then, at some point, abruptly, there were almost no solar particles, but a high level of cosmic rays. This signified that Voyager had reached the interstellar space.
A Different Transition
Voyager 2 encountered the same process when reaching for the interstellar space. However, it has gone through a rather different experience than its predecessor. Firstly, the high-energy cosmic rays were not accented by any of the abrupt waves the Voyager 1 saw.
However, levels of solar particles kept being stable through its reach to the margin of the Solar System. Then, instead of disappearing when the spacecraft reached interstellar space, solar particles kept getting to Voyager 2 for over 50 days after the transition.
Another important contradiction in data is that Voyager 2 has a functioning solar-wind sensing tool, which was not working on its predecessor. The density of the solar wind should, according to previous research, dilute with distance from the Sun. However, Voyager 2 registered that wind grew in power as the spacecraft headed towards the transition point, and also became rather energetic. This data implies that the transition makes the solar wind accumulate against the edge. Voyager 1 may have encountered the same thing but couldn’t record it.
Information that Contradicts
A potential explanation of the conflicting information could be the solar cycles. Voyager 1 reached the edge at a low period in solar activity, which might have had the margin pushing inward toward it. On the other hand, Voyager 2 crossed the boundary of the solar influence when solar activity was more intense.
Even if it is so, the Voyagers’ job is most likely done. The next development, the bow shock, which will reach the probe, will probably not be ready soon, JPL’s Edward Stone said at a press conference.
“When the two Voyagers were launched, the Space Age was only 20 years old,” Stone said. “We didn’t know things could last for 40 years out there.”