[Larry Lucido]

A new technique pinpointed the position of the ringed gas giant to within just two miles (four kilometers).

It doesn't stay still. How long does it take Saturn to travel two miles in its orbit?

[Balding_Eagle]

Average orbital speed, according to Wikipedia, is 9.69 km/second, which is about 6 miles.

[conservatism_IS_compassion]

It doesn't stay still. How long does it take Saturn to travel two miles in its orbit?

I’m assuming that "Very Long Baseline Array” technology is - or is an offshoot of - what was called “Synthetic Aperture Radar” twenty years ago.

The idea is that - using hi tech methods - you combine multiple radar “pings” from your moving radar into one measurement with the “antenna size” not limited to the size of your physical antenna but derived from past locations of your (satellite, in this case apparently) radar. Works for a moving target, IIRC.