Mars is brilliantly visible right now as it rises in the eastern sky during each evening.  It is near closest approach to earth, and with a small telescope can be resolved to show the distinctive disk of a nearby planet, along with a red color that gives it a peculiarity in the night sky.

Our nearest neighbor has been well studied, enough so that some speculation has taken place on it’s past climate.  Some would perhaps like to imagine an earthlike ancient past with a thick atmosphere and liquid water oceans.  After a violent history of volcanism, the internal dynamo in the convective mantel of the planet slowed down progressively. Mars no longer has the necessary magnetic field strength to protect itself from solar wind in the way that Earth does, so it is known that its atmosphere may have been stripped of much of it’s density, and as a result Mars has lost it’s insulating properties.

The question becomes, how different was it during this time, say, on the order of 1GYA.

Some surface features can only be accounted for if we consider short periods of massive flooding, but new findings published in nature suggest that this ancient ocean world was the exception and not the rule.  Instead, most of Mars’s history was spent with conditions much colder than that of earth.  It never possessed the atmosphere to encourage runaway warming and greenhouse effect. Don’t let this dampen your imagination though, because there is much more to learn about the past of our cold and not-so-distant neighbor.

http://www.nature.com/news/ancient-mars-probably-too-cold-for-liquid-water-1.15042