Facing harsh realities--in space, air, and war

Current legislative activity in Washington includes plans for hearings and proposed changes to NASA after the publication of the Columbia Accident Investigation Board report in August, 2003. Also reviewed are legislative interest in airline safety and armed forces expansion.     

Terahertz circular dichroism spectroscopy: a potential approach to the in situ detection of life's metabolic and genetic machinery

We propose a terahertz (far-infrared) circular dichroism-based life-detection technology that may provide a universal and unequivocal spectroscopic signature of living systems regardless of their genesis. We argue that, irrespective of the specifics of their chemistry, all life forms will employ well-structured, chiral, stereochemically pure macromolecules (>500 atoms) as the catalysts with which they perform their metabolic and replicative functions. We also argue that nearly all such macromolecules will absorb strongly at terahertz frequencies and exhibit significant circular dichroism, and that this circular dichroism unambiguously distinguishes biological from abiological materials. Lastly, we describe several approaches to the fabrication of a terahertz circular dichroism spectrometer and provide preliminary experimental indications of their feasibility. Because terahertz circular dichroism signals arise from the molecular machinery necessary to carry out life's metabolic and genetic processes, this life-detection method differs fundamentally from more well-established approaches based on the detection of isotopic fractionation, "signature" carbon compounds, disequilibria, or other by-products of metabolism. Moreover, terahertz circular dichroism spectroscopy detects this machinery in a manner that makes few, if any, assumptions as to its chemical nature or the processes that it performs.     

Synchrotron nebulae

The most frequent manifestation of synchrotron nebulae is the radio emission emanating from radio galaxies and supernova remnants. In general the synchrotron spectra of these objects do not extend into optical and x-ray domains presumably because the high energy electrons needed to sustain such emission are too short-lived. In fact, we knew of only one class of objects in which synchrotron nebulae are observed at frequencies above the radio, namely Crab-like supernova remnants (SNR). In these instances, a central pulsar is presumed to continually accelerate electrons up to the requisite energies, thus balancing the high synchrotron loss rate. The first part of this talk will discuss the available x-ray observations of these sources as well as some of the difficulties in their interpretation. The last part of the talk will be concerned with a new class of synchrotron nebulae associated with binary star systems.     

Initial estimates of Venus winds from ground-based radio tracking of the VEGA balloons

A global array of 20 radio observatories was used to measure the three-dimensional position and velocity of the two meteorological balloons that were injected into the equatorial region of the Venus atmosphere by the VEGA spacecraft. Initial analysis of only radial velocities indicates that each balloon was blown westward about 11,500 kilometers (8000 kilometers on the night side) by zonal winds with a mean speed of about 70 meters per second. Excursions of the data from a model of constant zonal velocity are generally less than 3 meters per second; however, a much larger variation is evident near the end of the flight of the second balloon. Consistent systematic trends in the residuals for both balloons indicate the possibility of a solar-fixed atmospheric feature.     

Communicating bioastronautics research to students, families and the nation

The National Space Biomedical Research Institute (NSBRI) is supporting the National Aeronautics and Space Administration's (NASA) education mission through a comprehensive Education and Public Outreach Program (EPOP) that communicates the excitement and significance of space biology to schools, families, and lay audiences. The EPOP is comprised of eight academic institutions: Baylor College of Medicine, Massachusetts Institute of Technology, Morehouse School of Medicine, Mount Sinai School of Medicine, Texas A&M University, University of Texas Medical Branch Galveston, Rice University, and the University of Washington. This paper describes the programs and products created by the EPOP to promote space life science education in schools and among the general public. To date, these activities have reached thousands of teachers and students around the US and have been rated very highly.