Tectonic setting of Martian volcanoes and deep-seated intrusives

More than 50 volcanoes have been mapped on Mars, and recent geologic studies indicate structural evidence of deep seated intrusive bodies. Most volcanoes in the Tharsis region are volcanotectonic features; they have been associated with large scale tectonic and volcanic processes. They occur along complex systems of faults and grabens having a dominant northwest to southwest trend closely coincident with a great circle, which extends along 90 deg of arc from Tempe Patera to probable volcanic mountains near lat. 40 deg S, long. 150 deg. Deep seated intrusive bodies are also concentrated in the Tharsis region and are recognized mostly where faults have been deflected around their cores. The Elysium Mons-Amphitrites Patera volcanic alignment is subparallel to that of Tharsis but is longer, extending through about 120 deg of arc; it transects the dichotomy boundary and is radial to the Hellas basin. Volcanoes in the Tharsis region have the widest age range of all volcanoes on Mars, as determined by the size-frequency distribution of their craters having diameters of 2, 5, and 16 km

Paleolakes and lacustrine basins on Mars

The problems of how warm and wet Mars once was and when climate transitions may have occurred are not well understood. Mars may have had an early environment similar to Earth's that was conducive to the emergence of life. In addition, increasing geologic evidence indicates that water, upon which terrestrial life depends, has been present on Mars throughout its history. This evidence does not detract from the possibility that life may have originated on early Mars, but rather suggests that life could have developed over longer periods of time in longer lasting, more clement local environments than previously envisioned. It is suggested herein that such environments may have been provided by paleolakes, located mostly in the northern lowlands and probably ice covered. Such lakes probably would have had diverse origins. Glacial lakes may have occupied ice eroded hollows or formed in valleys obstructed by moraines or ice barriers. Unlike Earth, the Martian record of the origin and evolution of possible life may have not been erased by extensive deformation of the surface. Thus the basins that may have contained the paleolakes are potential sites for future biological, geological, and climatological study

Variations in the onset diameter for Martian layered ejecta morphologies and their implications for subsurface volatile reservoirs

We investigated regional variations in the onset diameter of craters displaying a single layer ejecta morphology within +/- 30 degrees latitude using Viking imagery. Our results generally agree with those of previous studies which show onset diameters of 5 to 6 km in the equatorial region, but we have identified localized regions with unusually small onset diameters. The largest region is located in Solis and Thaumasia Planae. The 3-5 km onset diameter range in this area indicates a near-surface ice-rich reservoir (depth similar to 110 m). This unusual concentration of near-surface ice may have resulted from magmatic-driven uplifts associated with the Tharsis rise, which modified parts of a regional aquifer/drainage basin system and resulted in the transfer and concentration of subsurface volatiles in this region

Multiple-Agent Air/Ground Autonomous Exploration Systems

Autonomous systems of multiple-agent air/ground robotic units for exploration of the surfaces of remote planets are undergoing development. Modified versions of these systems could be used on Earth to perform tasks in environments dangerous or inaccessible to humans: examples of tasks could include scientific exploration of remote regions of Antarctica, removal of land mines, cleanup of hazardous chemicals, and military reconnaissance. A basic system according to this concept (see figure) would include a unit, suspended by a balloon or a blimp, that would be in radio communication with multiple robotic ground vehicles (rovers) equipped with video cameras and possibly other sensors for scientific exploration. The airborne unit would be free-floating, controlled by thrusters, or tethered either to one of the rovers or to a stationary object in or on the ground. Each rover would contain a semi-autonomous control system for maneuvering and would function under the supervision of a control system in the airborne unit. The rover maneuvering control system would utilize imagery from the onboard camera to navigate around obstacles. Avoidance of obstacles would also be aided by readout from an onboard (e.g., ultrasonic) sensor. Together, the rover and airborne control systems would constitute an overarching closed-loop control system to coordinate scientific exploration by the rovers

Automated Global Feature Analyzer - A Driver for Tier-Scalable Reconnaissance

For the purposes of space flight, reconnaissance field geologists have trained to become astronauts. However, the initial forays to Mars and other planetary bodies have been done by purely robotic craft. Therefore, training and equipping a robotic craft with the sensory and cognitive capabilities of a field geologist to form a science craft is a necessary prerequisite. Numerous steps are necessary in order for a science craft to be able to map, analyze, and characterize a geologic field site, as well as effectively formulate working hypotheses. We report on the continued development of the integrated software system AGFA: automated global feature analyzerreg, originated by Fink at Caltech and his collaborators in 2001. AGFA is an automatic and feature-driven target characterization system that operates in an imaged operational area, such as a geologic field site on a remote planetary surface. AGFA performs automated target identification and detection through segmentation, providing for feature extraction, classification, and prioritization within mapped or imaged operational areas at different length scales and resolutions, depending on the vantage point (e.g., spaceborne, airborne, or ground). AGFA extracts features such as target size, color, albedo, vesicularity, and angularity. Based on the extracted features, AGFA summarizes the mapped operational area numerically and flags targets of "interest", i.e., targets that exhibit sufficient anomaly within the feature space. AGFA enables automated science analysis aboard robotic spacecraft, and, embedded in tier-scalable reconnaissance mission architectures, is a driver of future intelligent and autonomous robotic planetary exploration

Is Earth-based scaling a valid procedure for calculating heat flows for Mars?

Heat flow is a very important parameter for constraining the thermal evolution of a planetary body. Several procedures for calculating heat flows for Mars from geophysical or geological proxies have been used, which are valid for the time when the structures used as indicators were formed. The more common procedures are based on estimates of lithospheric strength (the effective elastic thickness of the lithosphere or the depth to the brittle–ductile transition). On the other hand, several works by Kargel and co-workers have estimated martian heat flows from scaling the present-day terrestrial heat flow to Mars, but the so-obtained values are much higher than those deduced from lithospheric strength. In order to explain the discrepancy, a recent paper by Rodriguez et al. (Rodriguez, J.A.P., Kargel, J.S., Tanaka, K.L., Crown, D.A., Berman, D.C., Fairén, A.G., Baker, V.R., Furfaro, R., Candelaria, P., Sasaki, S. [2011]. Icarus 213, 150–194) criticized the heat flow calculations for ancient Mars presented by Ruiz et al. (Ruiz, J., Williams, J.-P., Dohm, J.M., Fernández, C., López, V. [2009]. Icarus 207, 631–637) and other studies calculating ancient martian heat flows from lithospheric strength estimates, and casted doubts on the validity of the results obtained by these works. Here however we demonstrate that the discrepancy is due to computational and conceptual errors made by Kargel and co-workers, and we conclude that the scaling from terrestrial heat flow values is not a valid procedure for estimating reliable heat flows for Mar

Biological Oxidant and Life Detection (BOLD) mission: an outline for a new mission to Mars

The Viking mission was the only mission to date that conducted life detection experiments. It revealed ambiguous and still controversial results. New findings and hypotheses urge a re-evaluation of the Viking results and a re-evaluation of the evidence for the possible presence of life on Mars in general. Recent findings of abundant water ice on Mars, the presence of liquid contemporary water on the Martian surface, and the detection of methane in the Martian atmosphere further support this possibility. Current missions to be launched focus on habitability considerations (e.g., NASA Phoenix, NASA Mars Science Laboratory), but shy away from directly testing for life on Mars, with the potential exception of the ESA ExoMars mission. If these currently planned missions collect positive evidence toward habitability and the possible existence of extraterrestrial (microbial) life on Mars, it would be timely to propose a new mission to Mars with a strong life detection component. We propose such a mission called BOLD: Biological Oxidant and Life Detection Mission. The BOLD mission objective would be to quantify the amount of hydrogen peroxide existing in the Martian soil and to test for processes typically associated with life. Six landing packages are projected to land on Mars that include a limited power supply, a set of oxidant and life detection experiments, and a transmitter, which is able to transmit information via an existing Mars orbiter back to Earth

A Near-Infrared Stellar Census of the Blue Compact Dwarf Galaxy VII~Zw~403

We present near-infrared single-star photometry for the low-metallicity Blue Compact Dwarf galaxy VII~Zw~403. We achieve limiting magnitudes of F110W~$\approx$~25.5 and F160W~$\approx$~24.5 using one of the NICMOS cameras with the HST equivalents of the ground-based J and H filters. The data have a high photometric precision (0.1 mag) and are $>95$% complete down to magnitudes of about 23, far deeper than previous ground-based studies in the near-IR. The color-magnitude diagram contains about 1000 point sources. We provide a preliminary transformation of the near-IR photometry into the ground system...Comment: Accepted for publication by the AJ, preprint has 49 pages, 2 tables, and 16 figure