Expecting the unexpected: field research in post-disaster settings

The purpose of this article was to examine field research after disasters by focusing on fieldwork challenges in post-disaster research settings. We describe and evaluate post-disaster fieldwork based on three separate research projects: A study of land use change adaptation strategies following the 2011 Great East Japan Earthquake and Tsunami; a study of long-term housing recovery following the 2001 Gujarat Earthquake in India; and a study of the role of social capital in shelter recovery following the 2010 Haiti Earthquake. The main findings of this study deal with some of the unique set of challenges that accompanies fieldwork in post-disaster settings. Our findings indicate six aspects that researchers might consider prior to undertaking fieldwork in a disaster setting: the critical role of language, logistics of transport and living accommodation, methodological matters, the researcher’s position in the field (i.e., gender, ethnicity), fieldwork blues and ethical concerns. Potential solutions to these challenges include understanding the target community prior to embarking on fieldwork, having flexibility in the field to deal with unexpected issues and problems, planning ahead for institutional review board approvals, forming research collaborations and having strategies in place to manage stress in the field.     

Assessment of organotin (butyltin species) contamination in marine biota from the Eastern Aegean Sea, Turkey

The marine environment continues to be adversely affected by tributyltin (TBT) release from maritime traffic. Therefore the concentrations of TBT, dibutyltin (DBT) and monobutyltin (MBT) were measured in barnacles, mussels and fish along the Eastern Aegean coastline. The average concentrations of TBT ng Sn g⁻¹ were found to be 235 in fish, 116 in mussels and 635 in barnacles. The highest concentrations of TBT, DBT and MBT were observed in the barnacles which had been sampled in marinas and harbors. All mussels sampled showed values of TBT + DBT, which were below the “tolerable average residue level (TARL)” as currently accepted. This indicates a lack of risk to the consumer. However, 7 out of the 15 fish sampled displayed TBT + DBT levels above the TARL, which indicates that a fish consumer group may be at risk. Barnacles have high potential as biomonitors for the presence of organotin in the Aegean Sea.     

A Model for the Common Origin of Jupiter Family and Halley Type Comets

A numerical simulation of the Oort cloud is used to explain the observed orbital distributions and numbers of Jupiter-family (JF) and Halley-type (HT) short-period (SP) comets. Comets are given initial orbits with perihelion distances between 5 and 36 au, and evolve under planetary, stellar and Galactic perturbations for 4.5 Gyr. This process leads to the formation of an Oort cloud (which we define as the region of semimajor axes a > 1,000 au), and to a flux of cometary bodies from the Oort cloud returning to the planetary region at the present epoch. The results are consistent with the dynamical characteristics of SP comets and other observed cometary populations: the near-parabolic flux, Centaurs, and high-eccentricity trans-Neptunian objects. To achieve this consistency with observations, the model requires that the number of comets versus initial perihelion distance is concentrated towards the outer planetary region. Moreover, the mean physical lifetime of observable comets in the inner planetary region (q < 2.5 au) at the present epoch should be an increasing function of the comets’ initial perihelion distances. Virtually all observed HT comets and nearly half of observed JF comets come from the Oort cloud, and initially (4.5 Gyr ago) from orbits concentrated near the outer planetary region. Comets that have been in the Oort cloud also return to the Centaur (5 < q < 28 au, a < 1,000 au) and near-Neptune high-eccentricity regions. Such objects with perihelia near Neptune are hard to discover, but Centaurs with characteristics predicted by the model (e.g. large semimajor axes, above 60 au, or high inclinations, above 40°) are increasingly being found by observers. The model provides a unified picture for the origin of JF and HT comets. It predicts that the mean physical lifetime of all comets in the region q < 1.5 au is less than ～200 revolutions.     

A concept of a space hazard counteraction system: Astronomical aspects

The basic science of astronomy and, primarily, its branch responsible for studying the Solar System, face the most important practical task posed by nature and the development of human civilization—to study space hazards and to seek methods of counteracting them. In pursuance of the joint Resolution of the Federal Space Agency (Roscosmos) and the RAS (Russian Academy of Sciences) Space Council of June 23, 2010, the RAS Institute of Astronomy in collaboration with other scientific and industrial organizations prepared a draft concept of the federal-level program targeted at creating a system of space hazard detection and counteraction. The main ideas and astronomical content of the concept are considered in this article.     

General presentation of secular part of the perturbing function of mutual attraction in the satellite system of a planet

A special presentation of secular part of the perturbing function of mutual attraction in the satellite system is presented. In contrast to known ones, it is given in general analytical form for any ratio between semimajor axes for perturbed and perturbing satellites.     

P/2010 TO20 LINEAR-Grauer: A comet in transition from Centaurs to the Jupiter family

The object P/2010 TO20 LINEAR-Grauer, discovered at a heliocentric distance of over 5 AU, and at first classified as a Trojan, is now believed to be a comet. This paper reports special observations of the object that have allowed a significant refinement of its orbit and investigation of its dynamic evolution. It is shown that P/2010 TO20 LINEAR-Grauer is not a Trojan yet demonstrates unusual dynamic features. In particular, the object moves in a temporary satellite orbit relative to Jupiter over the observation interval. The comet has been in the Hill sphere for about two years and has made one revolution around the planet. The jovicentric distance function has two minima, and the smallest distance is 0.075 AU. Our estimates show that, with a probability of 0.76, the comet is likely to move in a Jupiter family orbit with a perihelion distance of less than 2.5 AU. The average time for such a transition is around forty thousand years.     

Dynamics and Origin of Comets: New Problems Appeared after the <Emphasis Type="Italic">Rosetta</Emphasis> Space Mission

The data obtained in the recent Rosetta space mission to comet 67P/Churyumov–Gerasimenko have had a profound impact on the understanding of the nature of comets. In addition to revising the notions on the physical properties and structure of comets, this addresses dynamical aspects of the formation of the observed cometary populations (short- and long-period comets, Centaurs, trans-Neptunian objects, and Oort-cloud objects). In the review, we discuss new problems that have appeared in the theory of dynamical evolution and origin of comets due to the Rosetta mission.     

Long-Lived Near-Earth Asteroid 2013 RB6

The search for asteroids that maintain stable motion in the zone between the Earth and Mars has been performed. The near-Earth object 2013 RB6, which has avoided close encounters with the planets for a long period of time, has been found. Integration of the equations of motion of the object shows that its dynamical lifetime in the zone between the Earth and Mars significantly exceeds 100 Myr. 2013 RB6 moves away from orbital resonances with the planets, but is in the secular resonance ν₅. Solving the question of its origin requires further observations.     

Mutual occultations and eclipses of the Galilean satellites of Jupiter in 1997: Astrometric results of observations

In 2006, a complete database of the international campaign on photometric observations of the Galilean satellites of Jupiter in the 1997 epoch of mutual occultations and eclipses was published. Only two thirds of the observations were considered by other authors beforehand. In this study, we have processed the whole observational database with an original technique in order to obtain the astrometric data. We determined 301 relative positions of the satellites from photometric observations performed at 50 observatories around the world. The results are put into a common database of all observations of the natural planetary satellites called the Natural Satellites Data Center (NSDC) available on the Internet site http://www.sai.msu.ru/neb/nss/index.htm. The influence of random and systematic errors on the accuracy of determining the coordinates of satellites has been analyzed. It has been shown that the largest systematic errors are caused by inaccurate elimination of the background of the photometric measurements and by the erroneous data on the albedo of satellites. The actual accuracy of astrometric results is 0.05″ and 0.07″ in right ascension and declination, respectively. New recommendations for photometric observations of satellites during the considered phenomena have been developed in order to avoid the systematic errors.