Mercury a Venus

• Venus action on Mercury
• Solar day on Mercury and Venus

Venus action on Mercury

Venus is heavier than Mercury and revolves on a circular orbit. Mercury orbit is considerably eccentric.
After conjunction with Venus Mercury gets an additional impuls (Venus decreases moment of Mercury movement and it starts move like it was nearer to the Sun.) Before conjunction is Mercury on contrary decelerated.

Similar phenomena cause in case of satellites of Jupiter, Saturn and Uranus resonant motions. But Mercury and Venus do not show such a resonant binding. Conjunctions M-V appear also when Mercury is in aphelion, e.g. at end of year 1993 and near half of year 1999 (after c. 5.54 years):

(Interval) Conjunction M-V  Mercury in aphelion
( 0.378)   1993.989         1993.986 1994.227
( 0.381)   1994.370         1994.468 1994.709
( 0.433)   1994.802         1994.950
( 0.359)   1995.161         1995.191 1995.432
( 0.405)   1995.566         1995.672 1995.913
( 0.427)   1995.993         1996.154
( 0.348)   1996.341         1996.395 1996.636
( 0.419)   1996.760         1996.877 1997.118
( 0.422)   1997.182         1997.359
( 0.345)   1997.527         1997.600 1997.841
( 0.430)   1997.956         1998.082 1998.323
( 0.405)   1998.366         1998.564
( 0.356)   1998.718         1998.805 1999.046
( 0.433)   1999.150         1999.286
( 0.383)   1999.533         1999.528

But period 5.54 years (reminds half of the Wolf cycle) is not permanent; it disappear after 9 or 10 occurences (and new, phase shifted cycle arises).

Solar day on Mercury and Venus

Synchronization Mercury with Venus can be seen only in combination with rotation.
Solar day on Mercury lasts (M,Mr) = (87.969, 58.646) =175.938 days, on Venus (V,Vr) = (224.8008,-243.1)=116.796 days.

So it holds approximately:
(M,Mr)/(V,Vr)= 3/2 .
Solar day on Venus is 1.5 multiple of solar day on Mercury.

To keep periods exactly in this ratio some small changes are necessary, e.g. to shorten mean rotational period of Mercury by 2 hours.