What is different with retroviruses in reproduction is that they do not kill their hosts at first because they can still insert their own genome. This process is what is known the reverse transcription. This is done by different proteins.
The average distance is 16,000 km
Converging rate is 10 cm/year
1 km = 100,000 cm
= 16,000 × 100,000/10 cm/year
= 160,000,000 years
It will then take 160 Million years to collide.
