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NASA Spacecraft Data Suggest Water Flowing on Mars
August 04, 2011
PASADENA, Calif. -- Observations from NASA's Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars.
"NASA's Mars Exploration Program keeps bringing us closer to determining whether the Red Planet could harbor life in some form," NASA Administrator Charles Bolden said, "and it reaffirms Mars as an important future destination for human exploration."
Dark, finger-like features appear and extend down some Martian slopes during late spring through summer, fade in winter, and return during the next spring. Repeated observations have tracked the seasonal changes in these recurring features on several steep slopes in the middle latitudes of Mars' southern hemisphere.
"The best explanation for these observations so far is the flow of briny water," said Alfred McEwen of the University of Arizona, Tucson. McEwen is the principal investigator for the orbiter's High Resolution Imaging Science Experiment (HiRISE) and lead author of a report about the recurring flows published in Thursday's edition of the journal Science.
Some aspects of the observations still puzzle researchers, but flows of liquid brine fit the features' characteristics better than alternate hypotheses. Saltiness lowers the freezing temperature of water. Sites with active flows get warm enough, even in the shallow subsurface, to sustain liquid water that is about as salty as Earth's oceans, while pure water would freeze at the observed temperatures.
"These dark lineations are different from other types of features on Martian slopes," said Mars Reconnaissance Orbiter Project Scientist Richard Zurek of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Repeated observations show they extend ever farther downhill with time during the warm season."
The features imaged are only about 0.5 to 5 yards or meters wide, with lengths up to hundreds of yards. The width is much narrower than previously reported gullies on Martian slopes. However, some of those locations display more than 1,000 individual flows. Also, while gullies are abundant on cold, pole-facing slopes, these dark flows are on warmer, equator-facing slopes.
The images show flows lengthen and darken on rocky equator-facing slopes from late spring to early fall. The seasonality, latitude distribution and brightness changes suggest a volatile material is involved, but there is no direct detection of one. The settings are too warm for carbon-dioxide frost and, at some sites, too cold for pure water. This suggests the action of brines, which have lower freezing points. Salt deposits over much of Mars indicate brines were abundant in Mars' past. These recent observations suggest brines still may form near the surface today in limited times and places.
When researchers checked flow-marked slopes with the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), no sign of water appeared. The features may quickly dry on the surface or could be shallow subsurface flows.
"The flows are not dark because of being wet," McEwen said. "They are dark for some other reason."
A flow initiated by briny water could rearrange grains or change surface roughness in a way that darkens the appearance. How the features brighten again when temperatures drop is harder to explain.
"It's a mystery now, but I think it's a solvable mystery with further observations and laboratory experiments," McEwen said.
These results are the closest scientists have come to finding evidence of liquid water on the planet's surface today. Frozen water, however has been detected near the surface in many middle to high-latitude regions. Fresh-looking gullies suggest slope movements in geologically recent times, perhaps aided by water. Purported droplets of brine also appeared on struts of the Phoenix Mars Lander. If further study of the recurring dark flows supports evidence of brines, these could be the first known Martian locations with liquid water.
The Mars Reconnaissance Orbiter is managed by JPL for NASA's Science Mission Directorate in Washington. The University of Arizona's Lunar and Planetary Laboratory operates HiRISE. The camera was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Johns Hopkins University Applied Physics Laboratory in Laurel, Md., provided and operates CRISM. JPL is a division of the California Institute of Technology in Pasadena.
For more information about the Mars Reconnaissance Orbiter, visit: http://www.nasa.gov/mro andhttp://marsprogram.jpl.nasa.gov/mro/ .
"NASA's Mars Exploration Program keeps bringing us closer to determining whether the Red Planet could harbor life in some form," NASA Administrator Charles Bolden said, "and it reaffirms Mars as an important future destination for human exploration."
Dark, finger-like features appear and extend down some Martian slopes during late spring through summer, fade in winter, and return during the next spring. Repeated observations have tracked the seasonal changes in these recurring features on several steep slopes in the middle latitudes of Mars' southern hemisphere.
"The best explanation for these observations so far is the flow of briny water," said Alfred McEwen of the University of Arizona, Tucson. McEwen is the principal investigator for the orbiter's High Resolution Imaging Science Experiment (HiRISE) and lead author of a report about the recurring flows published in Thursday's edition of the journal Science.
Some aspects of the observations still puzzle researchers, but flows of liquid brine fit the features' characteristics better than alternate hypotheses. Saltiness lowers the freezing temperature of water. Sites with active flows get warm enough, even in the shallow subsurface, to sustain liquid water that is about as salty as Earth's oceans, while pure water would freeze at the observed temperatures.
"These dark lineations are different from other types of features on Martian slopes," said Mars Reconnaissance Orbiter Project Scientist Richard Zurek of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Repeated observations show they extend ever farther downhill with time during the warm season."
The features imaged are only about 0.5 to 5 yards or meters wide, with lengths up to hundreds of yards. The width is much narrower than previously reported gullies on Martian slopes. However, some of those locations display more than 1,000 individual flows. Also, while gullies are abundant on cold, pole-facing slopes, these dark flows are on warmer, equator-facing slopes.
The images show flows lengthen and darken on rocky equator-facing slopes from late spring to early fall. The seasonality, latitude distribution and brightness changes suggest a volatile material is involved, but there is no direct detection of one. The settings are too warm for carbon-dioxide frost and, at some sites, too cold for pure water. This suggests the action of brines, which have lower freezing points. Salt deposits over much of Mars indicate brines were abundant in Mars' past. These recent observations suggest brines still may form near the surface today in limited times and places.
When researchers checked flow-marked slopes with the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), no sign of water appeared. The features may quickly dry on the surface or could be shallow subsurface flows.
"The flows are not dark because of being wet," McEwen said. "They are dark for some other reason."
A flow initiated by briny water could rearrange grains or change surface roughness in a way that darkens the appearance. How the features brighten again when temperatures drop is harder to explain.
"It's a mystery now, but I think it's a solvable mystery with further observations and laboratory experiments," McEwen said.
These results are the closest scientists have come to finding evidence of liquid water on the planet's surface today. Frozen water, however has been detected near the surface in many middle to high-latitude regions. Fresh-looking gullies suggest slope movements in geologically recent times, perhaps aided by water. Purported droplets of brine also appeared on struts of the Phoenix Mars Lander. If further study of the recurring dark flows supports evidence of brines, these could be the first known Martian locations with liquid water.
The Mars Reconnaissance Orbiter is managed by JPL for NASA's Science Mission Directorate in Washington. The University of Arizona's Lunar and Planetary Laboratory operates HiRISE. The camera was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Johns Hopkins University Applied Physics Laboratory in Laurel, Md., provided and operates CRISM. JPL is a division of the California Institute of Technology in Pasadena.
For more information about the Mars Reconnaissance Orbiter, visit: http://www.nasa.gov/mro andhttp://marsprogram.jpl.nasa.gov/mro/ .
Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov
Steve Cole 202-358-0918
NASA Headquarters, Washington
stephen.e.cole@nasa.gov
Daniel Stolte 520-626-4402
University of Arizona, Tucson
stolte@email.arizona.edu
2011-242
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov
Steve Cole 202-358-0918
NASA Headquarters, Washington
stephen.e.cole@nasa.gov
Daniel Stolte 520-626-4402
University of Arizona, Tucson
stolte@email.arizona.edu
2011-242
6. The article has several opinions being displayed about the controversy on whether life is sustained on mars. Aside from this larger disagreement, the contributors to the article agree that there is research to show that mars contains briny water. The writer displays the idea that salt deposits on mars indicate that brine was abundant on Mars in the past. This leads to the observation that brine may still exist on the planet today. the writer goes on to persuade the audience of briny water existing on mars when he says, "A flow initiated by briny water could rearrange grains or change surface roughness in a way that darkens the appearance". To expand on the author's point of view he includes information from NASA'S Mars Exploration program. Richard Zurek also helps out the author by suggesting information on dark lineations and Martian slopes. The author continues on to say that dark water has been found near the surface. It is noted that there must be more research and observations of dark flows to see any Martian locations that contain liquid water. The author overall uses the information of science programs to agree that there could be more discoveries to Mars. The way the author explains off of the scientific evidence helps the audience understand the view of the author. I think that there is some sort of existence on Mars and in this article it is clear that there is evidence or observations that scientist have found that could lead to these conclusions. However, more research must be done to officially conclude the water and life existence on Mars and this will come with time. This topic of whether there is water flow on Mars is hard to discuss because there is only so much evidence that scientists have found.
ReplyDelete6. The first sentence of the article states that observations have revealed that there may be possible flowing of water on Mars during its warm months. This persuades the reader in advance before even beginning the rest of the article because when stating that there is a possibility of water on Mars, many know that this means there could be a sign of life. Authorities who are quoted in the article agree with the claim at the beginning who also state that there could have been a sign of life that had been found. The author of the article cites Alfred McEwen who is the principal investigator for the orbiter's High Resolution Imaging Science Experiment. McEwen in the article supports the author's claim because he states that the best explanation for the observations of possible water flow on Mars is the flow of briny water. After McEwen states his opinion on the briny water flow on Mars, the author then begins explaining that briny water is capable of rearranging grains or changing surface roughness. The author's explanation follows McEwen's which supports the fact that the author is attempting to improve upon someone else's idea which would have been McEwen's.
ReplyDelete6. This article has numerous thoughts about whether or not there is life on Mars. Research studies show that water has been found on Mars also. To help persuade us about the briny water, the author uses his information from the NASA program. The author uses all of the information from the research and the program to prove that there may be more findings on Mars. The author also uses the research and evidence to help the people to better understand the point he is trying to prove. I believe that there may be some kind of life on Mars and from this article, research, and evidence it is probable that there is. Nevertheless, more evidence must be found to legitimately complete the proof of the existence on Mars. But I do agree with the statement about it being hard to discuss the thought of water on Mars due to all of the research in the past.
ReplyDelete6. The article has some interesting new discoveries and theories about Mars and the posibility of flowing water during the warm seasons of the year. The article provides some evidence that testifies to the flowing water it is however not conclusive and leaves the dark lines to speculation. The opposition to the flowing water theory contends that this evidence does not only point to flowing water. The opposition states that just because the lines are dark does not mean they are liquid and that before they jump to conclusions further investigation and lab tests are required before they jump to the conclusion of liquid water. Whether or not it is liquid water this is still an exciting new discovery on the planet that humanity may inhabit one day in the future.
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