(Press-News.org) PROVIDENCE, R.I. [Brown University] — Roughly 3.5 billion years ago, the first epoch on Mars ended. The climate on the red planet then shifted dramatically from a relatively warm, wet period to one that was arid and cold. Yet there was at least one outpost that scientists think bucked the trend.
A team led by planetary geologists at Brown University has discovered mounds of a mineral deposited on a volcanic cone less than 3.5 billion years ago that speak of a warm and wet past and may preserve evidence of one of the most recent habitable microenvironments on Mars.
Observations by NASA's Mars Reconnaissance Orbiter enabled researchers to identify the mineral as hydrated silica, a dead ringer that water was present at some time. That fact and the mounds' location on the flanks of a volcanic cone provide the best evidence yet found on Mars for an intact deposit from a hydrothermal environment — a steam fumarole or a hot spring. Such environments may have provided habitats for some of Earth's earliest life forms.
"The heat and water required to create this deposit probably made this a habitable zone," said J.R. Skok, a graduate student at Brown and lead author of the paper in Nature Geoscience. "If life did exist there, this would be a promising spot where it would have been entombed — a microbial mortuary, so to speak."
No studies have determined whether Mars has ever supported life, but this finding adds to accumulating evidence that at some times and in some places, Mars hosted favorable environments for microbial life. The deposit is located in the sprawling, flat volcanic zone known as Syrtis Major and was believed to have been left during the early Hesperian period, when most of Mars was already turning chilly and arid.
"Mars is just drying out," Skok said, "and this is one last hospitable spot in a cooling, drying Mars."
Concentrations of hydrated silica have been identified on Mars previously, including a nearly pure patch found by NASA's Mars Exploration Rover Spirit in 2007. However, this is the first found in an intact setting that clearly signals the mineral's origin.
"You have spectacular context for this deposit," Skok said. "It's right on the flank of a volcano. The setting remains essentially the same as it was when the silica was deposited."
The small, degraded cone rises about 100 meters from the floor of a shallow bowl named Nili Patera. The patera spans about 50 kilometers (30 miles) in Syrtis Major of equatorial Mars. Before the cone formed, free-flowing lava blanketed nearby plains. The collapse of an underground magma chamber from which lava had emanated created the bowl. Subsequent lava flows, still with a runny texture, coated the floor of Nili Patera. The cone grew from even later flows, apparently after evolution of the underground magma had thickened its texture so that the erupted lava would mound up.
"We can read a series of chapters in this history book and know that the cone grew from the last gasp of a giant volcanic system," said John "Jack" Mustard, professor of geological sciences and a co-author of the paper, who is Skok's thesis adviser at Brown. "The cooling and solidification of most of the magma concentrated its silica and water content."
Observations by cameras on the Mars Reconnaissance Orbiter revealed patches of bright deposits near the summit of the cone, fanning down its flank, and on flatter ground in the vicinity. The Brown researchers partnered with Scott Murchie of Johns Hopkins University Applied Physics Laboratory to analyze the bright exposures with the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the orbiter.
Silica can be dissolved, transported and concentrated by hot water or steam. Hydrated silica identified by the spectrometer in uphill locations — confirmed by stereo imaging — indicates that hot springs or fumaroles fed by underground heating created these deposits. Silica deposits around hydrothermal vents in Iceland are among the best parallels on Earth.
"The habitable zone would have been within and alongside the conduits carrying the heated water," Murchie said.
###
NASA funded the research.
END
DARIEN, IL – A study in the Nov. 1 issue of the journal SLEEP found that vulnerability to sleep deprivation is influenced by the interaction between waking social activity and individual personality traits.
Results show that extraverts who were exposed to 12 hours of social interaction were more vulnerable to subsequent sleep deprivation than those who were exposed to an identical period of isolated activity. Speed on the Psychomotor Vigilance Task (PVT) for extraverts in the socially enriched group was significantly slower at 4 a.m., 6 a.m. and noon compared with speed ...
London, UK (November 1, 2010) – In April 2010, the US government adopted a new nuclear strategy that depends on the conclusion that the current missile defense systems will reliably protect the continental United States in the extreme circumstances of nuclear-armed combat. Now research in the Bulletin of Atomic Scientists, published by SAGE, shows that these defenses have not been tested against real-world threats and would not be effective in real combat conditions.
The April 2010 strategy relies on assumptions that the current US Ground-Based Missile Defense (GMD) and ...
Protected areas are generally seen as a triumph for the preservation of nature, yet the reality on the ground is more complex.
The world's largest protected areas encompass vast amounts of wilderness but do not extensively overlap the highest priority areas for conservation or include unusually large numbers of birds, amphibians, or mammals, according to an analysis published in the November issue of BioScience. The study, by Lisette Cantú-Salazar and Kevin J. Gaston of the University of Sheffield, United Kingdom, nonetheless describes anecdotal evidence that some very ...
Alexandria, VA — Racial and ethnic disparities among children with frequent ear infections (FEI) significantly influence access to affordable healthcare, according to new research published in the November 2010 issue of Otolaryngology – Head and Neck Surgery.
Ear infections are one of the most common health problems for children, with most kids experiencing at least one by their third birthday. Annual costs in the United States alone are in the billions of dollars.
Despite changes that have occurred in healthcare to help low-income children, such as the Children's ...
VIDEO:
Steven Moss, M.D., a gastroenterologist with Rhode Island Hospital, and his colleagues found that 33 individuals were responsible for 305 cases of medical intervention to remove foreign bodies that were...
Click here for more information.
PROVIDENCE, RI – A new study from Rhode Island Hospital found that 33 individuals were responsible for 305 cases of medical intervention to remove foreign bodies that were intentionally swallowed, resulting in more than $2 million in ...
SEATTLE--Primary-care clinicians know teen depression is common, but they've lacked a reliable screening test for it. Now researchers at the University of Washington (UW), Seattle Children's, and Group Health report the PHQ-9 (Patient Health Questionnaire - 9 item) is a good screening test for major depression in adolescents.
Led by Laura P. Richardson, MD, MPH, the team tested the PHQ-9 as a screening tool for depression in 442 teenage patients, age 13-17, at Group Health. The test is brief, available free of charge, easy to score and understand, and proven to find ...
LAWRENCE, Kan. – A little self-awareness can help people struggling in the world of relationships, says Jeffrey Hall, assistant professor of communication studies at the University of Kansas.
Hall recently completed a study into styles of flirting among dating adults, surveying more than 5,100 people regarding their methods of communicating romantic interest.
"Knowing something about the way you communicate attraction says something about challenges you might have had in your past dating life," Hall said. "Hopefully, this awareness can help people avoid those mistakes ...
Researchers have found that allergic infants may be at increased risk of peanut allergy if their mothers ingested peanuts during pregnancy. The data are reported in the November 1 issue of the Journal of Allergy and Clinical Immunology.
Led by Scott H. Sicherer, MD, Professor of Pediatrics, Jaffe Food Allergy Institute at Mount Sinai School of Medicine, researchers at five U.S. study sites evaluated 503 infants aged three to 15 months with likely milk or egg allergies or with significant eczema and positive allergy tests to milk or egg, which are factors associated with ...
Researchers have developed an efficient method for extracting and archiving CT radiation dose information that can enable providers to keep track of estimated radiation dose delivered to each patient at a given facility, help providers make more informed health care decisions and improve patient safety, according to a study in the November issue of the Journal of the American College of Radiology (www.jacr.org).
To facilitate access to and analysis of radiation dose information, researchers at the Hospital of the University of Pennsylvania in Philadelphia, PA, designed, ...
An overwhelming majority of Breast Cancer Surveillance Consortium (BCSC) facilities performing breast magnetic resonance imaging (MRI) in the U.S. are up-to-par with American College of Radiology Imaging Network (ACRIN) and European Society of Breast Imaging (EUSOBI) technical standards and requirements, according to a study in the November issue of the Journal of the American College of Radiology (www.jacr.org). The BCSC is a collaborative effort to improve breast cancer research. It consists of five mammography registries and two affiliated sites with linkages to pathology ...
