Part of a Pancam panorama obtained by the Spirit rover during its 90-sol nominal...  Full image

The "Mars Exploration Rover" (MER) "Spirit" has traversed more than 3 kilometers since landing across the low-relief, rock-strewn terrain on the floor of Gusev Crater. John Grant of the National Air and Space Museum and member of the MER Science Team reported on the 90-sol nominal mission in the August 6 issue of Science.  During the 90-sol (Mars days) nominal mission, the rover reached the rim of a nearby crater dubbed “Bonneville” revealing a surficial landscape dominated by impact, lesser eolian, and volcanic processes. Impacts have ejected basaltic rocks of uniform composition and probably local provenance, from at least 10 meters deep. Resultant craters are relatively shallow, have blocky walls sloped at relatively low gradients, and are probably formed as secondaries. The craters include the circular features dubbed “hollows” that vary in size, but are as small as about 1 meter in diameter. By contrast, eolian sediments are locally distributed and are frequently found within the craters and hollows. Bedrock was not encountered on the plains, and the surficial deposits sampled contained little diagnostic evidence for an ancient lake in Gusev Crater.

Spirit has recently reached the “Columbia Hills,” some 2.7 km to the southeast of the landing site. Deposits traversed along the trek to the Hills appear to embay their base. Interpretation of orbital data suggests the Hills are comprised of materials that may be more akin to those being stripped from the southeastern corner of the crater. The contrast in weathering style and relative erodability of some of the material forming the Hills suggests they are comprised of apparently more resistant bedrock layers interlaced with less resistant accumulations of possibly differing material properties, composition, and origin. Spirit is currently sampling bedrock units comprising the stratigraphic units forming the possibly older Hills. It will spend the coming weeks evaluating their origin to determine whether they may record a more complete history of the processes responsible for Gusev Crater infilling.

A map of the Moon's surface.  Full image

In collaboration with Cornell University and the Smithsonian Astrophysical Observatory, the National Air and Space Museum’s (NASM’s) Bruce Campbell recently completed new radar maps of the Moon, using the Arecibo Telescope to transmit a powerful radio signal and the Greenbank Telescope in West Virginia to receive the faint echoes. The radar maps have a spatial resolution of 400 meters, and the radar signal penetrates up to 6 meters into the mixed dust and rock that cover the Moon’s surface.

The new maps are being used to study how impact craters have reshaped the Moon’s landscape by pulverizing material and creating vast “haloes” of fine debris. One such radar-dark halo can be seen surrounding the bright crater Petavius (188-km diameter), marked by the arrow.  A second goal of this work is to map the distribution of ancient lava flows that were buried by material hurled from giant basin-forming impact events. These buried flows are extensive in some regions of the Moon, and can be used to trace the early history of lunar volcanic activity. Finally, these data are being used to support NASA’s plans for new robotic lunar orbiters and landers.

The masonry vaulted arches in the Old Patent Office Building. Because pure masonry structures...  Full image

For decades, museums have attempted to hold their environments as close as possible to a temperature of 70±2°F and a relative humidity of 50±5%. Research by Marion Mecklenburg and Charles Tumosa of the Smithsonian Center for Materials Research and Education (SCMRE) has shown that the recommended environmental limits are unnecessarily stringent, and in some cases have actually damaged museum property.

In a cover article of the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ monthly journal, Mecklenburg, Tumosa, and Alan Pride of the Smithsonian's Office of Facilities Engineering and Operations discuss new environmental guidelines, preserving and retrofitting Smithsonian buildings, reducing energy costs, and what can go wrong. Mecklenburg and Tumosa propose limits that are easier to meet: maintaining temperatures at 70±4°F and relative humidity at 45±8%.  These changes do not affect the stability of the collections, and, in fact, actually help the stability.

The lower relative humidity is expected to prevent condensation and the consequent building damage. It has reduced moisture and condensation damage to interior surfaces of exterior walls at the Renwick, Old Patent Office Building, and Hirshhorn, has halted the corrosion of the steel structural systems within the exterior walls, and has prevented further freeze-thaw damage to the exterior walls. More relaxed environmental limits can also reduce initial construction and subsequent operation costs by allowing for a smaller heating and air conditioning plant.

Since the Smithsonian's Office of Facilities Engineering and Operations has adopted these guidelines, it has realized substantial savings through reduced heating, ventilation, and air conditioning costs, and reduced capital investment in mechanical equipment for new construction and renovation. While these savings vary from building to building, they can be significant—possibly $500,000 or more at the Patent Office Building. Additionally, maintenance savings can run $500,000 or more annually.
SCMRE is working on the energy costs of operating all the Smithsonian’s buildings, based on data compiled from 1993 and 2003.

An image of Titan taken by a Voyager spacecraft. Titan is shrouded by a thick atmosphere made...  Full image

Titan, the largest of Saturn's 31 known satellites, is larger in diameter (5,150 kilometers) than than planet Mercury and is about 50 percent larger than our own moon. It is big enough, in fact, to have its own atmosphere. Astronomers have discovered that Titan has an atmosphere, whose major constituents are nitrogen (in this regard it is similar to the Earth's atmosphere) and methane gas (in this regard it is strangely different from the Earth's atmosphere where methane is only a minor component). Titan are also has traces of carbon monoxide (CO) gas in Titan.

The presence of even this unusual atmosphere on Titan offers the tantalizing prospect that its methane and nitrogen chemistry might support the creation of more complex hydrocarbons—the building blocks of life. Researchers sometimes refer to Titan's atmosphere as a possible analogue to the atmosphere of the early Earth, particularly in regard to pre-biotic chemistry. One of the prime goals of the Huygen's Probe onboard NASA's new Cassini spacecraft is to descend to the surface of Titan and provide detailed information about its mysterious atmosphere.

Smithsonian Astrophysical Observatory (SAO) astronomer Mark Gurwell has recently obtained some sensitive new measurements of Titan's atmosphere using SAO's Submillimeter Array (SMA) located on Mauna Kea, Hawaii. Writing in a paper soon to appear in The Astrophysical Journal Letters, Mark Gurwell reports finding that the CO in Titan's atmosphere has an abundance of about 51 parts per million, at odds with some earlier measurements. Furthermore, he finds that the SMA was able to detect traces of hydrogen cyanide gas (HCN) at a level of only 5 parts per million, and from those data he derives the temperature of the upper stratosphere as exceeding 180 kelvin—warmer than had previously been thought. Although these molecules had been detected before in Titan, besides contributing to the burgeoning study of Titan, these detailed new SMA results will help scientists trying to sort the conditions needed for life in the solar system.

Cereal grain.  Full image

How and when humans first processed and then cultivated cereal grains is a key question in human history, helping to illuminate the road that the human species took as hunter, gatherer, and farmer.

Dolores Piperno, who holds the first joint appointment at the Smithsonian Institution as research scientist with the Archaeobiology Program at the National Museum of Natural History and the Smithsonian Tropical Research Institute (STRI), along with STRI’s Irene Holstand and Harvard University’s Ehud Weiss, have published an article in Nature presenting evidence that pushes back the date for the processing of close wild relatives of domesticated wheat and barley to 23,000 years before the present era.

“Ten thousand years before people were cultivating cereals, they were processing wild barley. Starch grain analysis establishes a clear link between an intensive exploitation of wild cereals and the subsequent development of plant cultivation and domestication in the region,” explains lead author Piperno.

When the water level in the Sea of Galilee dropped in 1989, archaeologists uncovered ancient hut floors, and a large, flat, basaltic stone that yielded starch grains of grass seeds, mostly from wild barley and possibly also from wheat. Piperno and her colleagues analyzed the remains found on the stone’s surface, by comparing each microscopic grain to starch grains from hundreds of species maintained in a modern reference collection of plants. While grinding stones have been excavated from other Old World sites dated to 13,000–45,000 years before the present, there has never been conclusive evidence to show that they were used to grind cereal grains or other types of plants, and not pigments. 

Piperno adds, “We’re trying to find answers to two big questions: When were the first wild grains systematically collected as food, and when did people begin to process seeds and underground plant organs to turn them into more digestible and nutritious dietary elements.”

Guam Micronesian kingfisher.  Full image

A rare Guam Micronesian Kingfisher hatched in July at the National Zoo’s Conservation and Research Center (CRC) in Front Royal, Virginia. The first offspring from a genetically valuable pair, the chick weighed only 5.5 grams at hatching. When its parents refused to incubate the chick’s egg, CRC researchers removed the egg from the nest for artificial incubation and hand rearing.

According to CRC Bird Curator Scott Derrickson, “Few chicks have been hatched successfully from eggs receiving full-term artificial incubation, and hand rearing is extremely labor intensive.” Bird staff members Mark Albaugh, Carolyn Emerick, Warren Lynch, Rick Mazza, and Geoffrey Reynolds took turns feeding the young chick 7–8 times a day at two-hour intervals.

Like most of Guam’s native birds, kingfishers were decimated by an introduced predator, the brown tree snake, which migrated to Guam from Melanesia following World War II. The last wild Micronesian kingfisher was observed on Guam in 1986, and the species exists now only in captivity. The captive population, which numbers about 65 birds distributed among 12 zoos, is being managed under the auspices of the American Zoo Association's Species Survival Program (SSP). CRC research and animal care staff have been involved in all aspects of the SSP for this species since the program’s inception, and Derrickson serves on the SSP's Management Committee and the U.S. Fish & Wildlife Service's Recovery Team.
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The ultimate goal of the breeding program is to reintroduce kingfishers back to their native habitat on Guam. To support this effort, the SSP is increasing the captive kingfisher population as quickly as possible, and is working with Guam's Division of Aquatic and Wildlife Resources (DAWR) to establish a captive breeding facility on Guam. The DAWR facility received two male kingfishers from CRC in September 2003 and a breeding pair from the San Diego Zoo in April 2004, and additional transfers are planned. Also, field studies of wild kingfishers are underway on the island of Pohnpei, directed by former Smithsonian Postdoctoral Fellow Susan Haig.

Grant, J., et al. 2004. "Basaltic Rocks Analyzed by the Spirit Rover in Gusev Crater." Science (August 6, 2004), 305: 842-845.

Gurwell, M. "Submillimeter Observations of Titan: Global Measures of Stratospheric Temperature, CO, HCN, HC3N, and the Isotopic Ratios of 12C/13C and 14N/15N," The Astrophysical Journal Letters. In press.

Mecklenburg, M.F.; Tumosa, C.S.; and Pride, A. June 2004. “Preserving Legacy Buildings.” ASHRAE Journal. Special Supplement: HVAC Retrofit. 46/6: S18-S23.

Piperno, D.R.; Weiss, E.; Holst, I.; and Nabel, D. 2004. “Processing of Wild Cereal Grains in the Upper Paleolithic Revealed by Starch Grain Analysis.” Nature, August 5, 2004.