Mars was once thought to be a fairly unchanging planet, similar to the Moon. But now we know it is a planet that was shaped by water and other forces in the past — and that these forces still come into play today.
Above is a picture of permafrost deposits just discovered in Louth Crater. This find comes from NASA’s Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE) and you can see some of its latest water- and dust- shaped environments imaged below.
“A still-unexplained feature of this crater is the diffuse dark smudges visible on the crater floor,” read an update on the University of Arizona HiRISE website explaining this image. “These resemble ‘defrosting spots’ which are visible on carbon dioxide ice in the early spring, but they occur on frost-free areas and survive throughout the summer.”
The frost was caught in a HiRISE image early in the summer, and it persisted as controllers watched it through the summer — indicating that it is permanent. Its size did diminish somewhat, however. Scientists are pretty sure that this is water ice, as carbon dioxide can’t survive the summer.
Up to two-thirds of Earth’s permafrost likely will disappear by 2200 as a result of warming temperatures, unleashing vast quantities of carbon into the atmosphere, says a new study by the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences (CIRES).
The carbon resides in permanently frozen ground that is beginning to thaw in high latitudes from warming temperatures, which will impact not only the climate but also international strategies to reduce fossil fuel emissions, said CU-Boulder’s Kevin Schaefer, lead study author. “If we want to hit a target carbon dioxide concentration, then we have to reduce fossil fuel emissions that much lower than previously thought to account for this additional carbon from the permafrost,” he said. “Otherwise we will end up with a warmer Earth than we want.” Continue reading “Study: Thawing Permafrost Could Accelerate Global Warming”