Planetary astronomy

Many asteroids are known to be non-spherical, as revealed by changes in their brightness as they rotate (light curves) and present varying cross-sections to view. Models of collisional evolution of the asteroid belt suggest that many of the larger asteroids are shattered rubble piles, consisting of fragments bound together by gravity. If these assemblages are sufficiently weak, they should relax to equilibrium shapes that depend only on their spin periods and densities. Thus, if shape of an asteroid is known, one might infer its density and internal structure

Spectrophotometric study of asteroids

Observations of particular faint asteroids of interest, in particular the Trojans, were carried out during an observation run at Kitt Peak National Observatory (1.3 meter telescope) in September 1973, and an attempt was made to study the compositional variation within Hirayama families. A particularly important study was initiated to observe spectrophotometrically certain asteroids which are considered as potential source bodies for meteorites. A program was also undertaken to coordinate the spectrophotometry program with polarimetric and thermal-infrared observation programs being conducted elsewhere

Switching circuit Patent

Solid state circuit for switching alternating current input signal as function of direct current gating transisto

Asteroid selection for mission opportunities

A study to assess the present state of knowledge of asteroids as well as the rate of change of that knowledge to better identify the mission and target priorities for advanced planning of asteroidal flights in the 1980's is presented. Topics discussed include; the present state of asteroid knowledge, the scientific goals and priorities attached to asteroid exploration, the anticipated advances in knowledge over the current decade, asteroid mission consideration, and asteroid selection. Data sheets for 118 asteroids are contained. These are asteroids for which some data is available over and above orbital parameters and magnitude

The role of earth-based observations of asteroids during the next decade

Present reconnaissance studies of asteroids shift ground based programs to more specialized, intensive studies of selected individual bodies and special classes. Two powerful techniques--radar and mid-IR spectroscopy--have yet to be widely applied to asteroids; high priority should be given to: (1) search programs with a large Schmidt telescope (especially for Mars- and Earth-approaching bodies); (2) a moderate resolution visible and near-IR spectrophotometric survey of at least half the asteroids; (3) high resolution spectrophotometry and radiometry of unusual objects; (4) radar studies of representative main belt asteroids; and (5) application of the full complement of astrophysical techniques to objects of high scientific interest and to potential space mission targets. The infrared astronomical satellite also has high potential for contributing to asteroid science

An analysis of the Mariner 4 photography of Mars

Crater analysis of Mariner 4 photography of Mar

Modelling the measured local time evolution of strongly nonlinear heat pulses in the Large Helical Device

In some magnetically confined plasmas, an applied pulse of rapid edge cooling can trigger either a positive or negative excursion in the core electron temperature from its steady state value. We present a new model which captures the time evolution of the transient, non-diffusive local dynamics in the core plasma. We show quantitative agreement between this model and recent spatially localized measurements (Inagaki et al 2010 Plasma Phys. Control. Fusion 52 075002) of the local time-evolving temperature pulse in cold pulse propagation experiments in the Large Helical Device

Planetary astronomy program

Observations and analyses of asteroids, Trojans and cometary nuclei are presented. Spectrophotometry was used to observe the cometary nuclei. The spectra are plotted as a function of semimajor axis and eccentricity. Trojans and other asteroids at great solar distances show a variety of spectra, many of them quite red despite the low measured albedoes for many of these asteroids. The asteroid spectra are grouped according to diameter and taxonomic class