Future oceans on a terraformed Mars
Mars has been the subject of more speculation than any other planet in the Solar System. There is also a wealth of information on the web regarding all aspects of this planet. Rather than regurgitate what may have been better expressed elsewhere, the box at the bottom of this web page points the way to the best of these resources.
The focus of this Mars web page will be two topics of possible significance for Mars' future: caves and terraforming. Establishment of initial human bases on the planet will be greatly facilitated by the use of natural voids that may be remodeled for habitation. A permanent human presence requires some sort of terraforming of the planet.
On the terraformed globe image above, Arsia Mons is the last volcano to the southwest in the straight row of three. Olympus Mons, Mars' highest mountain, is the separate volcano to the northwest of the trio. A closeup of the four volcanos brings out greater detail.
The seven openings on the right were discovered on the slopes of Arsia Mons. A detailed scan of the martian surface could probably find a lot more such openings in volcanic regions of the planet.
Evidence that the holes may be openings to cavernous spaces comes from the temperature differences detected from infrared images taken in the afternoon vs. the pre-dawn morning. "Whether these are just deep vertical shafts or openings into spacious caverns, they are entries to the subsurface of Mars," said co-author Tim Titus of the U.S. Geological Survey in Flagstaff. "Somewhere on Mars, caves might provide a protected niche for past or current life, or shelter for humans in the future."
Lava caves can be quite large. A closeup of one of the seven, 150 meters in diameter, clearly shows a vertical shaft.