Venus has an induced magnetosphere, created by an ionized layer in the ionosphere. That said, it is theorized that 4 or 5 billion years ago Venus used to have more liquid water on the surface and in the atmosphere, and over time that many of the lighter gases (such as water vapor) have been blown away by the solar wind, and those gases continue to be blown away, resulting in the atmosphere we see today.
As I said earlier, for Mars to have an atmosphere including water vapor, some protective layer would have to be created. I should have been clearer and stated it did not have to be a magnetosphere.
Mass is not the issue; the lack of a magnetosphere is. Without a magnetosphere, the solar wind will strip the atmosphere, leaving you in the same state. We would need to provide some means of creating a field which shields the atmosphere from solar winds.
Did a quick google to find an article - this one was published in 2010: http://science.nasa.gov/science-news/science-at-nasa/2001/ast31jan_1/
Because Lindbergh was the first to do it solo
And Alcock and Brown weren't the first to make the flight over the Atlantic, although they were the first to do a non-stop. The crew of the NC-4 did it first (but they used more than one aircraft) Alcock and Brown did have balls - climbing out on the wings to chip off the ice as they flew.
Work is the crab grass in the lawn of life. -- Schulz