(Abdul Ahad) wrote in message . com...
I was casually checking the weekly mission data archived he-
http://voyager.jpl.nasa.gov/mission/...orts/index.htm

when I noted the velocities of both probes (relative to the Sun) were
edging lower by small amounts over the past 8 years:

Jan 1996 Voyager 1: 17.4 km/s, Voyager 2: 16.1 km/s
Jan 1999 Voayger 1: 17.3 km/s, Voayger 2: 15.9 km/s
Jan 2002 Voyager 1: 17.2 km/s, Voyager 2: 15.7 km/s
Jan 2004 Voayger 1: 17.2 km/s, Voyager 2: 15.7 km/s

Any ideas as to what's causing this slow down anyone? I was expecting
no decelerations until we reach the first signs of the theoretical
'Oort Cloud' or some other medium that would equally lead to an
extinction of Voyagers' onboard radio telemetry relay by a
proportional measure. Is the craft's speed reduction connected in some
way with the expected slow down in the speed of the solar wind as it
nears the 'termination shock' I wonder... Or is there some hitherto
unknown relativistic effect of some kind at play here?

Abdul Ahad


Um, gravity? Maybe Kepler's Second law has something to do with this....