Update on Martian Cave Skylights
As we all know, the entrance to seven possible caves had been found on the slopes of a Martian volcano. Discovered by NASA’s Mars Odyssey, interest is also being stimulated as to possible underground habitats and the possibility of looking elsewhere on the planet for additional caves.
Researchers are bewildered by very dark, nearly circular features with a diameter ranging from 100 to 250 meters (328 to 820 feet) from images taken by NASA’s Mars Odyssey and Mars Global Surveyor orbiters. After checking daytime and nighttime temperatures of the circles, using Mars Odyssey’s infrared camera, scientists reported that they could see windows into underground spaces. Images showing a patch of Martian surface, which were focused on a possible cave skylight informally called “Annie,” with a diameter about double the length of a football field.
Temperature differences detected from infrared images taken in the afternoon and in the pre-dawn morning provide evidence that the holes may possibly be openings to cavernous spaces. Temperatures of the holes change from day to night about one-third as much as the change in temperatures of the surrounding ground surface. Glen Cushing of the U.S. Geological Survey’s Astrology Team and of Northern Arizona, Flagstaff, Arizona said, “They are cooler than the surrounding surface in the day and warmer at night. Their thermal behavior is not as steady as large caves on Earth that often maintain a fairly constant temperature, but it is consistent with there being deep holes in the ground.
The journal, Geophysical Research Letter, recently published a report online of the discovery of the possible cave skylights by Cushing and his co-authors. Co-author Tim Titus of the U.S. Geological Survey in Flagstaff said, “Whether these are just deep vertical shafts or openings into spacious caverns, they are entries to the subsurface of Mars. Somewhere on Mars, caves might provide a protected niche for past or current life, or shelter for humans in the future.” Named “Seven Sisters”, the discovered holes are located at some of the highest altitudes on the planet, on a volcano named Arsia Mons near Mars’ tallest mountain. “These are at such extreme altitude, they are poor candidates either for use as human habitation or for having microbial life,” said Cushing. “Even if life has never existed on Mars, it may not have migrated to this height.
The deep holes on Arsia Mons probably formed as underground stresses around the volcano caused spreading and faults that opened space beneath the surface as proposed by the new report. Some of the holes are in line with strings of bowl-shaped pits where surface material has apparently collapsed to fill the gap created by a linear fault. Mars Odyssey and NASA’s Mars Reconnaissance Orbiter are being used by researchers to examine the “Seven Sisters”. Their goal is to find other openings to underground spaces at lower elevations that are more accessible to future missions to Mars.
This entry was posted on Wednesday, February 20th, 2008 at 8:37 am and is filed under Mission History, Space Agency News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
