Robin Fergason ( Phone: 928-556-7034 );
TEMPE, Ariz. – A heat-sensing camera designed at Arizona State University has provided data to create the most detailed global map yet of Martian surface properties. The map uses data from the Thermal Emission Imaging System (THEMIS), a nine-band visual and infrared camera on NASA’s Mars Odyssey orbiter. An online version of the map optimized for scientific researchers is also available.
The new Mars map was developed by Robin Fergason of the U.S. Geological Survey Astrogeology Science Center in Flagstaff, Arizona, in collaboration with researchers at ASU's Mars Space Flight Facility. The work reflects the close ties between space exploration efforts at Arizona universities and the USGS.
"We used more than 20,000 THEMIS nighttime temperature images to generate the highest resolution surface property map of Mars ever created," said Fergason, who earned her Ph.D. degree at ASU in 2006. "Now these data are freely available to researchers and the public alike."
Surface properties tell geologists about the physical nature of a planet or moon's surface. Is a particular area coated with dust, and if so, how thick is it likely to be? Where are the outcrops of bedrock? How loose are the sediments that fill this crater or that valley? A map of surface properties lets scientists begin to answer such questions.
The new map uses nighttime temperature images to derive the "thermal inertia" for football field-sized areas of Mars. Thermal inertia is a calculated value that represents how fast a surface heats up and cools off. As night follows day on Mars, loose fine-grain materials such as sand and dust change temperature quickly and thus have low values of thermal inertia. Bedrock has a high thermal inertia because it cools off slowly at night and warms up slowly by day.
"Darker areas in the map have a lower thermal inertia and likely contain fine particles, such as dust, silt or fine sand," said Fergason. “Brighter regions have higher thermal inertia surfaces, consisting perhaps of coarser sand, surface crusts, rock fragments, bedrock or combinations of these materials.”
The designer and principal investigator for the THEMIS camera is Philip Christensen, Regents' Professor of Geological Sciences in the School of Earth and Space Exploration, part of the College of Liberal Arts and Sciences on the Tempe campus. Four years ago, Christensen and ASU researchers used daytime THEMIS images to create a global Mars map depicting the planet's landforms, such as craters, volcanoes, outflow channels, landslides, lava flows and other features.
"A tremendous amount of effort has gone into this great global product, which will serve engineers, scientists and the public for many years to come," Christensen said. "This map provides data not previously available and will enable regional and global studies of surface properties. I'm eager to use it to discover new insights into the recent surface history of Mars."
Fergason noted that there's a practical side, too.
"NASA used THEMIS images to find safe landing sites for the Mars Exploration Rovers in 2004 and Curiosity, the Mars Science Laboratory rover, in 2012," she said. "THEMIS images are now helping to select a landing site for NASA's next Mars rover in 2020."
DENVER – This month marks two key wildfire anniversaries, which serve as an important reminder that families need to take proactive steps to protect themselves and their property against wildfires.Language English
EATONTOWN, N.J. -- New Jersey comes by its nickname, “The Garden State,” honestly, as the agricultural industry brings more than $987 million into the state’s economy. The state is among the top ten producers of cranberries, peaches, spinach, bell peppers, blueberries, cucumbers, squash and tomatoes in the United States, according to the New Jersey Farm Service Agency.Language English
JACKSON, Miss. – Rebuilding or repairing property damaged from the recent severe storms? Residents can get advice on building safer and stronger this week from Federal Emergency Management Agency specialists in Rankin County.
FEMA mitigation specialists will be at Lowe’s in Flowood Tuesday through Saturday to offer information on rebuilding after a disaster. The advisors can answer questions about protecting homes from future disaster-related damage and offer tips to build hazard-resistant homes.Language English
Following is a summary of key federal disaster aid programs that can be made available as needed and warranted under President Obama's disaster declaration issued for the State of Iowa.
Assistance for the State and Affected Local Governments Can Include as Required:Language English
WASHINGTON, D.C. – The U.S. Department of Homeland Security's Federal Emergency Management Agency announced that federal disaster aid has been made available to the State of Iowa to supplement state and local recovery efforts in the area affected by severe storms, tornadoes, straight-line winds and flooding during the period of June 3-4, 2014.Language English
This new global geologic map of Mars depicts the most thorough representation of the “Red Planet’s” surface. This map provides a framework for continued scientific investigation of Mars as the long-range target for human space exploration.(High resolution image)
A new global geologic map of Mars –the most thorough representation of the "Red Planet's" surface – has been published by the U.S. Geological Survey. This map provides a framework for continued scientific investigation of Mars as the long-range target for human space exploration.
The new map brings together observations and scientific findings from four orbiting spacecraft that have been acquiring data for more than 16 years. The result is an updated understanding of the geologic history of the surface of Mars – the solar system’s most Earth-like planet and the only other one in our Sun’s “habitable zone.” The new geologic map of Mars is available for download online.
For hundreds of years, geologic maps have helped drive scientific thought. This new global geologic map of Mars, as well as the recent global geologic maps of Jupiter’s moons Ganymede and Io, also illustrates the overall importance of geologic mapping as an essential tool for the exploration of the solar system.
"Spacecraft exploration of Mars over the past couple decades has greatly improved our understanding of what geologic materials, events and processes shaped its surface," said USGS scientist and lead author, Dr. Kenneth Tanaka. “The new geologic map brings this research together into a holistic context that helps to illuminate key relationships in space and time, providing information to generate and test new hypotheses.”
The USGS-led mapping effort reveals that the Martian surface is generally older than previously thought. Three times as much surface area dates to the first major geologic time period - the Early Noachian Epoch - than was previously mapped. This timeframe is the earliest part of the Noachian Period, which ranges from about 4.1 to about 3.7 billion years ago, and was characterized by high rates of meteorite impacts, widespread erosion of the Martian surface and the likely presence of abundant surface water.
The map also confirms previous work that suggests Mars had been geologically active until the present day. There is evidence that major changes in Mars’ global climate supported the temporary presence of surface water and near-surface groundwater and ice. These changes were likely responsible for many of the major shifts in the environments where Martian rocks were formed and subsequently eroded. This new map will serve as a key reference for the origin, age and historic change of geological materials anywhere on Mars.
"Findings from the map will enable researchers to evaluate potential landing sites for future Mars missions that may contribute to further understanding of the planet’s history," said USGS Acting Director Suzette Kimball. "The new Mars global geologic map will provide geologic context for regional and local scientific investigations for many years to come."
The Martian surface has been the subject of scientific observation since the 1600s, first by Earth-based telescopes, and later by fly-by missions and orbiting spacecraft. The Mariner 9 and Viking Orbiter missions produced the first planet-wide views of Mars’ surface, enabling publication of the first global geologic maps (in 1978 and 1986-87, respectively) of a planetary surface other than the Earth and the Moon. A new generation of sophisticated scientific instruments flown on the Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter spacecraft has provided diverse, high quality data sets that enable more sophisticated remapping of the global-scale geology of Mars.
The production of planetary cartographic products has been a focal point of research at the USGS Astrogeology Science Center since its inception in the early 1960s. USGS began producing planetary maps in support of the Apollo Moon landings, and continues to help establish a framework for integrating and comparing past and future studies of extraterrestrial surfaces. In many cases, these planetary geologic maps show that, despite the many differences between bodies in our solar system, there are many notable similarities that link the evolution and fate of our planetary system together.
The project was funded by NASA through its Planetary Geology and Geophysics Program.
The mission of the USGS Astrogeology Science Center is to serve the Nation, the international planetary science community, and the general public’s pursuit of new knowledge of our solar system. The Team’s vision is to be a national resource for the integration of planetary geosciences, cartography, and remote sensing. As explorers and surveyors, with a unique heritage of proven expertise and international leadership, USGS astrogeologists enable the ongoing successful investigation of the solar system for humankind. For more information, visit Astrogeology Science Center
Jennifer LaVista ( Phone: 303-202-4764 );
Seasonal carbon dioxide frost, not liquid water, is the main driver in forming gullies on Mars today, according to a recent U.S. Geological Survey study that relied on NASA’s Mars Reconnaissance Orbiter’s (MRO) repeated high-resolution observations.
Martian gullies are landforms typically consisting of steep channels, usually having a recessed head, that feed into a fan of material deposited at the bottom. The discovery of active gullies was first reported in 2000, which generated excitement due to consideration that they might result from action of liquid water. Mars has water vapor and plenty of water ice, but liquid water, a necessity for all known life, has not been confirmed on modern Mars. The new report, published in the journal Icarus, is available online.
"As recently as five years ago, I thought the gullies on Mars indicated activity of liquid water," said USGS scientist Colin Dundas, lead author of the new report. "We were able to get many more observations, and as we started to see more activity and pin down the timing of gully formation and change, we saw that the activity is in winter."
A smaller type of seasonal flow seen on some slopes on Mars may involve liquid water, but is yet to be determined. These flows are called recurring slope lineae (RSL), and are sometimes found within small channels but not systematically associated with larger gullies.
Dundas and collaborators used the High Resolution Imaging Science Experiment (HiRISE) camera on MRO to examine each of 356 Martian sites with gullies at least twice, beginning in 2006. Thirty-eight of the sites showed activity, such as cutting a new channel segment or adding material to the apron-shaped deposit at the downhill end of a gully. Wherever the timing of before-and-after observations enabled determining the season of gully activity, it was a time too cold for the possibility of melting water-ice, but consistent with seasonal carbon dioxide frost.
"RSL and mass movements in Martian gullies are two distinct types of slope activity,” said Dundas “It's not hard to tell them apart in HiRISE images. The classic Martian gullies are much larger than RSL. Many of them are more the size that you'd call ravines on Earth."
Frozen carbon dioxide, commonly called dry ice, does not exist naturally on Earth, but it is plentiful on Mars. It has been linked to active processes on Mars such as geysers of carbon dioxide gas from springtime sublimation of dry ice, and blocks of dry ice that plow lines on sand dunes by sledding down dunes on cushions of sublimated gas. One mechanism for how carbon dioxide frost might drive gully flows is by gas that is sublimating from the frost, providing lubrication for dry material to flow. Another might be slides due to accumulating weight of seasonal frost buildup on steep slopes.
Work by Dundas and others has previously pointed to winter timing of gully formation on dune and non-dune slopes, with suggested involvement of seasonal changes in frozen carbon dioxide. The new report adds evidence for the changes. The findings also make a new point that the pace of gully formation that has now been documented is swift enough that all of the fresh-appearing gullies seen on Mars can be attributed to current processes. Some earlier hypotheses attributing the gullies to action of liquid water have suggested they formed thousands to millions of years ago when climate conditions were possibly more conducive to Mars having liquid water due to variations in the planet's tilt and orbit.
Dundas' co-authors on the new report are Serina Diniega of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, and Alfred McEwen of the University of Arizona, Tucson.
"Much of the information we have about gully formation and other active processes on Mars comes from the longevity of MRO and other orbiters,” said Diniega. “This enables repeated observation of sites to examine changes over time."
Data will appear in an upcoming special issue of Icarus with multiple reports about active processes on Mars, including RSL.
"I like that Mars can still surprise us," Dundas said. "Martian gullies are fascinating features where we can investigate a process that we just don't see on Earth."
HiRISE is operated by the University of Arizona. The instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. The Mars Reconnaissance Orbiter Project is managed for NASA's Science Mission Directorate, Washington, by JPL.
Visit the USGS Astrogeology Center to learn more.
Visit HiRISE for more information.
Additional information about MRO is available online.These two images show changes in a gully on Mars, and illustrate that these landforms are evolving rapidly. A rubbly flow (noted by the arrows) has been deposited near the mouth of the channel between the time of the two images. Further up the slope, the channel system has been modified by both erosion and deposition. The timing of such changes is often in winter or early spring, suggesting that they are caused by the carbon dioxide frost that forms in and around most gullies every year. (High resolution image)
ANCHORAGE, Alaska — Monitoring wildlife in the Arctic is difficult. Study areas are cold, barren and often inaccessible. For decades scientists have struggled to study animals, like polar bears, which live in these remote areas. Now researchers at the U.S. Geological Survey have begun testing a new, yet counterintuitive solution – rather then get close to the animals, monitor them from afar. Scientists have started using satellites to observe, count and track polar bears. USGS scientists and their Canadian collaborators have begun analyzing high-resolution satellite images from a part of the Canadian High Arctic to determine the feasibility of using satellites to study polar bear populations.
“We tested the use of satellite technology from DigitalGlobe to count polar bears by tasking the satellite to collect photos from an area where we were also conducting aerial surveys,” said Dr. Todd Atwood, research leader for the USGS Polar Bear Research Program. “We then analyzed the satellite and aerial survey data separately and found that the abundance estimates were remarkably similar.”
The study, which is led by former USGS scientist and current University of Minnesota researcher Dr. Seth Stapleton, is part of an ongoing effort to identify non-invasive technologies to better understand how polar bears respond to the loss of sea ice due to a warming climate. This study tries to determine the number of polar bears and where they reside on Rowley Island in Nunavut’s Foxe Basin during the ice-free summer. “We selected Rowley as our study site because bear density is high during summer and the flat terrain provides an ideal setting to evaluate the use of satellite imagery,” said Stapleton.
Traditionally, scientists study polar bears by capturing and tagging them or by conducting aerial surveys with low flying aircraft. While these methods provide a wealth of important information, they are disruptive to the animals and are often not possible when dealing with remote locations. “We think satellite technology has the potential to open vast, remote regions of the Arctic to regular monitoring. It has tremendous potential to aid the circumpolar management of polar bears,” said Stapleton.
The next steps in the research focus on testing the satellites’ ability to detect polar bear populations over larger areas, including sites along coastal Alaska. Using satellite imagery shows incredible promise and provides one more tool for those interested in preserving polar bear populations for future generations.