It takes a lot of delta v to get to Mercury and orbit the planet, so multiple sling shot manuvers were done to keep the cost of the probe from being excessive. Neil

Yes I can make a hard copy of pictures and text I put on slashdot, and other websites, but the copies get lost, the websites purge the old stuff or disappear completely. My computers loose the stuff on them about once per year. Redundant times 4 or 5 is costly and/or time consuming. Even deciding what we want to keep long term is time consuming. there does not appear to be any good solution. Neil

I suspect the power of green house gasses has been seriously exaggerated by the green house warming crowd. Thus: The Equator of Mars would not be tropical (temperate perhaps) even if Mars had an atmosphere like Venus. That likely means nearly all the water would be traped in the ice caps at the poles if we terriform now. It is thought that the sun was hotter 4.6 billion years ago as a proto-sun, but that it cooled shortly after it went main sequence; likely before the bombardment ended. The last 4.5 billion years we think the sun has been gradually getting warmer, so Earth-like for Mars is unlikely any time in the last 4.5 billion years. Our theories may be wrong, and Mars may have had a comfortable climate as resently as a century ago. I expect we will find extremeophile micro organisms below the surface of Mars; but intelegent life is unlikely unless we are victums of a massive dis-information campaign. Neil Please try to make serious rather than funny comments.