[SunkenCiv]

There is a difficult-to-kill wish that Mars was once "Earthlike", but it's apparent that it has never had much atmosphere. Venus must get hit very hard by the solar wind -- the atmosphere must have been even more massive than it is now, unless of course Venus migrated into its current orbit, which isn't terribly unlikely, given its lack of tidal lock with the Sun (Venus has a slow retrograde axial rotation).

[Telepathic Intruder]

We know Mars once had liquid water, due to its many dried up river beds, which is not possible now.

But does that alone qualify as "earth-like"? At some point Mars lost its magnetic field and the solar wind took away most of its atmosphere, and the water froze or evaporated. That is the most common theory I've heard. It was also hit by a very big asteroid. Maybe it was a combination of the two.

But you have a point which changes mine. Likely this 'second Earth' is similar to Mars, or similar to Venus. Very unlikely that without a magnetic field it's similar to Earth, however. At least not for very long.

[fieldmarshaldj]

“The Solar Wind, came blowin’ in, from across the Sun...”