Smithsonian Science » natural history

Gale Crater to be landing site for NASA’s Mars Science Laboratory

John Barrat — Fri, 22 Jul 2011 16:29:12 +0000

During a press conference Friday, July 22 at the Smithsonian’s National Air and Space Museum, NASA announced that Gale Crater will be the landing site for the Mars Science Laboratory. Scheduled to launch in late 2011 and arrive at Mars in August 2012, the Mars Science Laboratory is a rover that will assess the planet’s “habitability”—if it ever was, or is today, an environment able to support microbial life.

“Having the right instruments and knowing where to go are equally important,” said John Grant, a Smithsonian geologist and co-chair of the landing site steering committee. “We looked for a site that has water associated with it, materials of interest that are concentrated and preserved and that is accessible so we can get to it. Gale Crater is a good place to explore because there is a mountain of layered materials rising from its floor. Much like chapters in a book, the sediments, minerals and layers in this stack record the story about what Mars was like in the past. The rover will investigate where sediments forming the layers came from and explore how the layers relate to the environments in which they formed.” Grant, who is a researcher in the Center for Earth and Planetary Studies, is also a member of the science team for Mars rovers Spirit and Opportunity.

Image right: Gale Crater is 96 miles in diameter and holds a layered mountain rising about 3 miles above the crater floor. The portion of the crater within the planned landing area north of the mountain has an alluvial fan likely formed by water-carried sediments. The lower layers of the nearby mountain–within driving distance for Curiosity–contain minerals indicating a wet history. (Image NASA/JPL-Caltech/ASU)

The car-sized Mars Science Laboratory, or Curiosity, is scheduled to launch late this year and land in August 2012. The target crater is 96 miles in diameter and holds a mountain rising higher from the crater floor than Mount Rainier rises above Seattle. Gale is about the combined area of Connecticut and Rhode Island. Layering in the mound suggests it is the surviving remnant of an extensive sequence of deposits.

Image left: This artist concept shows NASA’s Mars Science Laboratory Curiosity rover, a mobile robot for investigating Mars’ past or present ability to sustain microbial life. In this picture, the rover examines a rock on Mars with a set of tools at the end of the rover’s arm, which extends about 7 feet. (Image NASA/JPL-Caltech)

During a prime mission lasting one Martian year—nearly two Earth years—researchers will use the rover’s tools to study whether the landing region had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed.

In 2006, more than 100 scientists began to consider about 30 potential landing sites during worldwide workshops. Four candidates were selected in 2008. An abundance of targeted images enabled thorough analysis of the safety concerns and scientific attractions of each site. A team of senior NASA science officials then conducted a detailed review and unanimously agreed to move forward with the MSL Science Team’s recommendation. The team is comprised of a host of principal and co-investigators on the project.

NASA Video: Animation of the Mars Science Laboratory from entry, descent and landing phase to surface operation.

Curiosity is about twice as long and more than five times as heavy as any previous Mars rover. Its 10 science instruments include two for ingesting and analyzing samples of powdered rock that the rover’s robotic arm collects. A radioisotope power source will provide heat and electric power to the rover. A rocket-powered sky crane suspending Curiosity on tethers will lower the rover directly to the Martian surface.

The rover and other spacecraft components are being assembled and are undergoing final testing. The mission is targeted to launch from Cape Canaveral Air Force Station in Florida between Nov. 25 and Dec. 18. NASA’s Jet Propulsion Laboratory in Pasadena manages the mission for the agency’s Science Mission Directorate in Washington. JPL is a division of Caltech.

Introducing Leafsnap, an electronic field guide to North America trees run on a mobile phone app

John Barrat — Thu, 02 Jun 2011 13:38:09 +0000

Puffer fish voucher library

John Barrat — Tue, 31 May 2011 17:14:49 +0000

Puffer fish (Tetraodontidae) are masters of self-defense. When threatened they blow up like a balloon. Not only does this make them harder to swallow, but some puffer fish have sharp spines covering their body. If a predator does take a bite some species have powerful neurotoxins in their flesh and organs. Under carefully controlled circumstances, certain species of poisonous puffer fish can be safe to eat, but ingesting even a small amount of their neurotoxins can cause serious illness. Click HERE to read how scientists at the Smithsonian and the FDA are collaborating to improve public food safety through the development of a DNA puffer-fish voucher library.

The puffer fish at right is the speciesTakifugu xanthopterus and is a specimen from the voucher library of the Smithsonian’s National Museum of Natural History. (Photo courtesy Keichii Matsuura)

Pink tourmaline “Nautilus” pendant enters National Gem Collection

John Barrat — Mon, 23 May 2011 15:02:51 +0000

The Smithsonian’s National Gem Collection in the Department of Mineral Sciences of the Smithsonian’s National Museum of Natural History, recently added the “Nautilus” pendant to its collection as the gift of Thomas Dailing. The pendant, designed by Dailing, took Grand Prize in the National Saul Bell Design Competition in 2008. It features a beautiful 3.76-ct pink tourmaline from Nigeria. The 18k yellow gold pendant involves a spiral based on Descartes’ equiangular spiral, a parabolic dish, and a truncated cone made of spiraling white gold wires. This pendant blends reflection and form together to create the effect of the inside of a chambered nautilus shell. It is centered with a “Phantom Spinner” tourmaline, a new cut by Richard Homer. The tourmaline has a polished drill hole running through its axis, allowing a tube set diamond to rest on its center, with no visible connection. The intense pink color of the tourmaline is magnified and reflected throughout the pendant due to this ingenuous design.

Gulf of Mexico survey will benchmark diversity of ocean floor

John Barrat — Tue, 08 Mar 2011 14:04:35 +0000

Twenty three researchers led by University of Florida by scientist Gustav Paulay are participating in an expedition in March to survey the biodiversity of the Gulf of Mexico’s ocean floor.

Funded by BP through the Florida Institute of Oceanography, the scientists will make the 10-day trip aboard the institute’s 115-foot research vessel. The divers, scientists and photographers will document hard bottoms of Florida, from the Keys to the Panhandle, to gain a better understanding of these sponge- and coral-dominated communities.

Image right: The RV Weatherbird II, a research vessel of the Florida Institute of Oceanography.

The expedition is the most comprehensive biodiversity study of the hard grounds along the west Florida shelf and includes researchers from other Florida institutions, as well as Old Dominion University, the Virginia Museum of Natural History and the Smithsonian Institution. Researchers plan to repeat the survey next year to observe short-term changes in biodiversity. The data will be useful for science as well as the fishing industry.

“Certainly we will potentially notice effects from the oil spill, but the primary issue is that we have an oil spill in our backyard and we have a very limited understanding of the marine communities and diversity of organisms out there,” said Paulay, curator of malacology at the Florida Museum of Natural History on the UF campus.
Scientists will post initial findings and photographs on the Florida Museum’s invertebrate zoology blog, spinelessscience.blogspot.com. Further results will be posted online as the information is analyzed.

The trip will be carried out in two legs, with 14 researchers on each segment. The 194-ton R/V Weatherbird II will travel south from St. Petersburg to the Florida Keys March 4-9, then north from St. Petersburg to the Panhandle March 10-14. Researchers will focus on two areas: a quantitative assessment of marine life and an observational survey of the species found.

Divers will venture 30 to 100 feet underwater to reach the hard-bottom communities, which in Florida are typically fossilized limestone reefs and beds, with a thin sand veneer in places. These support large, attached animals like sponges, corals, sea fans, sea squirts and sea weeds giving structural complexity to the bottom.–-University of Florida

Narwhal fluke design helps compensate for drag caused by tusk

John Barrat — Wed, 09 Feb 2011 14:51:58 +0000

The spiral tusk of the male narwhal can weigh as much as 22 pounds and reach 9 feet in length. Now scientists have determined that pushing their tusks through the water has, over millennia, changed the shape of the other end of the narwhal—its flukes.

Image right: These CT topograms illustrate the differences in shape between female (top left and right) and male (bottom left and right) narwhal flukes.

Using 3-D computerized tomography to study variations in fluke geometry between male and female narwhals, researchers have determined the variation is directly related to swimming performance. Male narwhal flukes have a slightly concave leading edge with no sweepback. Female narwhals have no tusks, and their flukes are similar to that of a dolphin, which have a swept back leading edge. The male’s fluke design helps it overcome the drag caused by their long tusks, the scientists determined. The female’s fluke design gives them increased speed for diving while foraging.

Image left: Narwhals tusking (Image courtesy National Institute of Standards and Technology)

The researchers also studied cross sections of the flukes, which were legally obtained from aboriginal hunters in Canada. For both sexes of narwhal, the fluke cross-sections were highly streamlined, having a rounded leading edge and a tapering, trailing edge, the researchers say.

Scientists who participated in this study are Janet Fontanella and Frank Fish of West Chester University; Natalia Rybczynski of the Canadian Museum of Nature; Martin Nweeia of Harvard University and the Smithsonian’s National Museum of Natural History; and Darlene Ketten of Woods Hole Oceanographic Institution. Their findings were published in a recent issue of the journal Marine Mammal Science.

Potential biofuel pest, the switchgrass moth, under renewed scrutiny of entomologists

John Barrat — Mon, 29 Nov 2010 13:45:41 +0000

Scientists are learning more about the life stages and biology of an insect that may compete with humans for the energy crops of the future—an insect some scientists are calling the switchgrass moth.

Image left: A switchgrass moth adult (Photo by Paul Johnson)

In an recent article in the journal Zootaxa, researchers from the Smithsonian Institution, South Dakota State University and the University of Nebraska, for the first time described the immature stages of the insect species Blastobasis repartella, first described in scant detail from two male specimens of the adult moth collected in Denver, Colo., in 1910. The article re-describes the adult insect far more closely and discusses some aspects of its biology in relation to its host plant, switchgrass. Blastobasis repartella bores into the stems of switchgrass.

The insect has gain come to the attention of agricultural scientists because native grasses like switchgrass are being considered as candidates for the large-scale production of cellulosic ethanol, a next-generation biofuel.

Image right: David Adamski

Already in May 2004 at the Dakota Lakes Research Farm of South Dakota State University, professor Arvid Boe, a forage and biomass grass breeder, and postdoctoral research associate DoKyoung Lee estimated that up to 40 percent of new tillers of a few scattered plants of switchgrass were lost to the caterpillar of the switchgrass moth.

Paul Johnson, curator of SDSU’s Severin-McDaniel Insect Research Collection and a research associate in the Entomology Department of the Smithsonian’s National Museum of Natural History in Washington, D.C., collected adult moths using simple emergence traps in 2008, and estimated their population densities. SDSU scientists first suspected the stem-borer might be a new species. But David Adamski, entomologist with the USDA’s Agricultural Research Service, research associate at the Smithsonian, and a specialist in small moths, ultimately identified the insect.

Image left: Arvid Boe in a switchgrass plot maintained by South Dakota State University. (Image courtesy South Dakota State University)

Adamski is the lead author of the journal article. Professors Paul Johnson and Arvid Boe, both of South Dakota State University, are co-authors, along with J.D. Bradshaw of the University of Nebraska-Lincoln and Alan Pultyniewicz of Columbia, Md.

The journal article notes that while some Blastobasis species feed on various grasses, Blastobasis repartella “appears to be restricted to switchgrass.”

If farmers grow switchgrass as a biomass crop in the future, Johnson says, it is very likely that switchgrass moth populations will increase along with the acres devoted to the grass. This means it is very likely that agricultural producers will want researchers to develop insect control regimens to limit damage to energy crops.

Image right: Paul Johnson with insect traps in a field of switchgrass. (Image courtesy South Dakota State University)

The journal article notes that switchgrass larvae are presumably inactive during the coldest months. They were found to be active in South Dakota when plants were brought into the greenhouse in early spring and forced into early growth. In the field, mature larvae are commonly found actively feeding in late May.

Adults of Blastobasis repartella are nocturnal with a peak of activity during the pre-sunrise hours. In eastern South Dakota, adult activity occurs primarily from mid-July to mid-August. Seasonal peak adult activity related to reproductive behavior was measured by the frequency of arriving males (40–50 males per night and occasionally exceeding 75 males per night) at cages containing calling females.

There is no evidence to suggest the occurrence of a second generation or overlapping cohorts in either South Dakota or Illinois populations, the researchers say. This is consistent with the single per year growth of switchgrass and appears to correlate with geographic variations in growing season differences of switchgrass, Boe said.–Lance Nixon, South Dakota State University

Yup’ik mask in “Infinity of Nations” exhibition at the American Indian Museum

John Barrat — Thu, 21 Oct 2010 20:26:12 +0000

This circa 1910 Yup’ik mask from Good News Bay, Alaska–made of driftwood, baleen, feathers, paint and cotton twine–is part of “Infinity of Nations: Art and History in the Collections of the National Museum of the American Indian,” an exhibition at NMAI’s George Gustav Heye Center in New York City. Opening Saturday, Oct. 23, the exhibition features 700 works of Native art from throughout North, Central and South America.

Study reveals hazards of the high-wire life for bromeliads

John Barrat — Fri, 10 Sep 2010 13:19:45 +0000

A common epiphytic plant that pulls the nutrients it needs to live out of thin air has been conducting a high-wire act in Panama. Wind-born seeds of the bromeliad Tillandsia flexuosa have long been lodging, sprouting and appearing to thrive in the grooves of aluminum-wire wrapped electric power lines. These plants grow unprotected in the blazing tropical sun using a thick layer of water- and nutrient-absorbing scales to pull sustenance from the air. Their roots hold them fast to the cable.

Right and below: T. flexuosa growing on power lines in Panama (Photos courtesy Gerhard Zotz)

Recently, botanists Gerhard Zotz of the Smithsonian Tropical Research Institute and Stefan Wester of the University of Oldenburg in Germany decided to take a closer look at these high-wire bromeliads. They were interested to find out how the growth and survival rates of these plants on electrical cables compared to the growth and survival of plants of the same species growing in trees–their natural environment.

During a two-year study the pair surveyed some 1,400 T. flexuosa specimens living on 1250 meters of electrical cable, as well as nearby plants of the same species growing on tree limbs. The cables were 8.25 millimeters in diameter and consisted of multiple aluminum wires woven around a single steel cable, giving them a rough surface upon which the seeds and plants can cling. Before their study the scientists observed that most of the cable-growing T. flexuosa lived on cables near roads, leading them to theorize that the dust kicked-up by cars and other vehicles provided adequate nutrients for the plants to flourish.

Although the high-wire T. flexuosa appeared to be thriving, Zotz and Wester found the cables were actually a hostile environment for the plants. T. flexuosa on power lines grew slowly, suffered a high mortality rate and were not very successful in establishing new recruits. On electric cables the death of established plants greatly exceeded the recruitment of new plants from seeds.

For these bromeliads the primary problem with cable-life, the scientists found, is a lack of water. While individuals growing on both cables and trees utilize rainwater, the zero water-absorbing properties of an aluminum cable combined with greater exposure to the sun and wind, make cable life for bromeliads highly risky. Even though dust from cars should provide an abundance of nutrients to the cable-living bromeliads, lack of water prevented them from taking advantage of this benefit.

In addition, the scientists found that even though the cables had a rough surface, the plants had a difficult time anchoring themselves to the cable. Many of the plants disappeared during the course of the study, dislodged from the cables by wind and other natural forces.

The study, the first to examine the growth and survival of electric-cable growing bromeliads, was published recently in the Journal of Tropical Ecology. –John Barrat

Slide Show: Smithsonian’s National Museum of Natural History is 100!

John Barrat — Tue, 22 Jun 2010 17:24:14 +0000

Since its doors first opened in 1910, the National Museum of Natural History has inspired curiosity and learning about the natural world and our place in it. Building upon the strong foundation of our extensive collections, the staff of the museum have been at the forefront of essential scientific exploration and research, and groundbreaking public exhibition and education. This slideshow and the website (www.mnh.si.edu/onehundredyears/) is a living documentary of the Museum’s 100-year history.