Outflowchannels are probably relics of catastrophic flooding on Mars long ago.
流出通道可能是很久以前火星上发过洪水的遗迹。
2
Flooding shaped the outflowchannels approximately 3 billion years ago, about the same times as the northern volcanic plains formed.
大约30亿年前,洪水形成了流出通道,大约与北部火山平原形成的时间相同。
3
Even setting aside the unproven hints of ancient oceans, the extent of the outflowchannels suggests that a huge total volume of water existed on Mars in the past.