Question

"January 2 was crucial for the voyagers ". How?

Answer 1

As of August 2017, Voyager 1 was at a distance of 20.8 billion kilometers (139.3 AU) from the Sun.

Voyager 2 was at a distance of 17.2 billion kilometers (115 AU).

Voyager 1 is escaping the solar system at a speed of about 3.6 AU per year.
Voyager 2 is escaping the solar system at a speed of about 3.3 AU per year.

There are currently five science investigation teams participating in the Interstellar Mission. They are:

1. Magnetic field investigation
2. Low energy charged particle investigation
3. Cosmic ray investigation
4. Plasma Investigation (Voyager 2 only)
5. Plasma wave investigation

Five instruments onboard the Voyagers directly support the five science investigations. The five instruments are:

1. Magnetic field instrument (MAG)
2. Low energy charged particle instrument (LECP)
3. Cosmic ray instrument (CRS)
4. Plasma instrument (PLS)
5. Plasma wave instrument (PWS)

One other instrument is collecting data but does not have official science investigation associated with it:

6. Ultraviolet spectrometer subsystem (UVS), Voyager 1 only