Terraforming Mars is a mistake

There was something on Instapundit that discusses the subject.

Perhaps he- and those others who advocate it- don't know that Mars will not keep its terraformed condition any more that it kept it originally.  You see, if Mars was once wet, it means that Mars had an atmosphere that could support water in liquid form.  Furthermore, that implies that the atmosphere was much thicker than now.

So, what happened to it?

There is a theory that Mars lost its atmosphere to the solar wind.  It stripped away the atmosphere and will do so again if it were to return.

It doesn't happen on Earth because Earth has a magnetic field.  Mars does not.   It is rather pointless to terraform Mars unless you can give it a magnetic field strong enough to deflect the solar wind.