Clues on Mars Show Its Climate Past
Mars and Earth both have had or have signs of water on them, making them both water planets. However, water on Mars is seldom a liquid such as what is on Earth, instead existing as a gas or appearing on the surface as ice. As several international countries have sent up telescopes and cameras that are orbiting Mars, they are also sending back images that have a sharper focus on the planet’s surface, able to bring forth some new facts about the red planet with ever-changing data.
Clues regarding water and climate on the planet Mars shows us the history of its climate changes. Patterned ground on the higher altitudes of Mars are similar to that of Earth’s Antarctic and Arctic, suggesting an expansion and contraction of icy ground caused by cycles of cooling and warming. The pictures now reveal a range of ice-made features that show a strong preference to certain latitudes according to James Head, Mars researcher of Brown University. He explains that latitude-dependent features can mean only one thing, latitude-dependent climate, based on similar findings on Earth.
Water-ice signs are obvious at both of the Martian poles. As you get near the equator, there are many clues to show the presence of water that shaped the surface in a variety of ways over the many years. Close to both poles are large areas of bumpy, polygonal-patterned ground, suggesting the contraction and expansion of icy permafrost ground in the past. Located between 30 and 60 degrees latitude in both hemispheres, this patterned-ground gave way to a pervasive pitted texture of once ice-rich dust deposits.
Tell tale signs of large glaciers, nearly the same as those on Earth, have been found close to the equator on the edge of the Martian equatorial volcanoes. Glacial debris in small valleys have filled craters which drop into canyons. On Earth, this scenario would be a strong indicator that a glacier once filled and widened the canyon. The ice was removed from the area by being sublimed away and then deposited at the poles. The ice dominates these temperate latitudes only when the tilt of Mars’ spin axis is more than 45 degrees. The poles are exposed to an excess of sun during the course of a Martian year because of the tilt or obliquity.
When the water develops the ability to refreeze on the surface in the, all the evidence of ice and glaciers have been revealed. “It’s a quest to understanding the Martian water cycle”, said Head as he described his work. Instruments used to study Mars include the Mars Global Surveyor’s Laser Altimeter (MOLA), and Camera (MOC) the Mars Reconnaissance Orbiter’s Context Camera (CTX) and High Resolution Imaging Science Experiment (HIRISE) and the Mars Express’s High Resolution Stereo Camera (HRSC).
This entry was posted on Tuesday, February 5th, 2008 at 2:24 am and is filed under Mission History. 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.
