Could Venus be a source of Earth's apparent overabundance of water? I've watched documentaries about the solar system, where it is suggested that Venus once had oceans of liquid water similar to those that cover most of Earth today.  Venus is now in a period of runaway greenhouse effect and has lost its oceans.  

I've always wondered whether the apparent overabundance of water on Earth could be partially explained by our planet sweeping up the water, pushed into Earth's path by the solar wind, after it had been liberated from Venus.  I know one theory on where our water came from is a bombardment of comets - but I've always wondered whether some could also have arrived after Venus heated up.

How stupid is this as an idea?



edits:-

10/12/2014 - article from the bbc - Rosetta results: Comets 'did not bring water to Earth'

20/09/2017 - article from www.spacetelescope.org - Hubble discovers a unique type of object in the Solar System which includes an interesting note - "[2] Current research indicates that water came to Earth not via comets, as long thought, but via icy asteroids."
No idea is stupid per se.  But in order to place an answer to your question, please consider Venus as a comet. It once had, in that image, a coma (a tail) pointing outwards from the sun, made of evaporated water pushed away by solar wind. How frequently is the Earth exactly inside that coma?

As a comparison, when the Earth strikes a real comet coma we see meteor showers that last no more than one day. So if we consider that Earth may go through Venus imaginary coma once a year, we have an upper limit of 1/365 of Venus' water captured by Earth. This, without taking into effect that Venus had not have a real coma, that evaporation and expelletion of water from Venus was not a so directional process, and surely other factors I can not think about just now.

Besides, do not consider comets the main source of water on Earth. You need to count also with the water vapour generated on volcanoes and that generated on acid-base reactions among Earth's rocks.