View Full Version : Mystery of the Martian Rilles

2011-Oct-12, 11:50 PM
When the first spacecraft flew by Mars in the 1960′s, the images returned revealed a relatively uninteresting-looking place, featureless in some areas and pockmarked with craters in most others. It looked a lot like the Moon. Later flybys and orbiting probes, however, gave us a closer look at other regions on the planet, providing a [...]

More... (http://www.universetoday.com/89822/mystery-of-the-martian-rilles/)

2011-Oct-13, 01:36 AM
How about a compromise between lava tube and water in the form of ice that got covered by dirt, then sublimed away, leaving the collapse features?