It was recently discovered by the Mars Reconnaissance Orbiter, which has been in orbit around the Red planet since 2006, that Mars has a series of channels that lead underground. These channels once housed flood-waters long, long ago when the planet was a much warmer and wetter place.
The channels extend more than 600 miles (1,000 kilometers) under the Martian surface and were likely gouged through the iron oxide soil after a volcanic eruption (or an earthquake), which forced a large collection of water into what is now called “Marte Vallis” about 500 million years ago. The channels became obscured after another volcanic eruption took place in the Elysium Planita plain, covering the channel. Until this point, the existence of these channels was unknown. Recently, scientists used MRO’s radar capabilities to “un-Earth” them.
According to scientists, the Mars Reconnaissance Orbiter is equipped with an Italian made tool (called “SHARAD” [Mars SHAllow RADar sounder]) that was designed to pick up traces of water and water-ice underground. Mars has been a desolate world that is devoid of liquid water on the surface for quite some time (bar the concentrations of ice that is locked away in the north and south poles of the Red planet). There is only trace evidence of its existence in the way of ancient streambeds that are no longer functional. These beds were discovered by Spirit, Opportunity, and Curiosity.
The tool is quite exceptional, as it has a horizontal resolution that is between 0.3 and 3 kilometers with a resolution of about 15 meters (50 feet) vertically, discovering that the largest of the channels is about the height of a skyscraper 113 meters (370 feet). According to the paper, which was published in “Science:” “This is comparable with the depth of incision of the largest known mega-flood on Earth, the Missoula floods.” The flood referenced flooded western North America after the last ice age, which occurred between 12,000 to 18,000 years ago.
In addition to this being an incredible discovery on its own merits, this may also play a fundamental role in helping us understand the Martian Martes Vallis, and eventually unlock the mystery of what happened to Mars between the period of this flooding and its current evolutionary period.