[揽瓜阁精读] 221.火星上有水

Helen698

谢谢！

Helen698

221
1. Photographic evidence - two types of flow features - Runoff channels' location and the time of rivers
2. Outflow channels' cause, regions, difference with Runoff channels, formed islands, enormous flow rates, and the time.
3. Early Period - 2003 image shows that may be a delta - Other suggests, large open expenses of water - computer generated view, may be an ancient ocean - another candidate for sea
4. Controversial - Proponents believe the beaches is evidence of the evaporated ocean and receded shoreline - Detractors argues the terraces could be created by geological activity - data released in 2003, too few carbonate rock layers to be the evidence of an ocean - However, more recent data shows at least parts once had liquid water
Astronomers have no direct evidence of water today - the amount of water vapor tiny - where did all the water go ? permafrost