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"Is it possible to predict the fall of a meteors before it's fall? And how could we protect ourselves from this fall? "
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Assessing the likelihood of supernova impact of protoplanetary disks
Project Investigators: Eric Gaidos, Sean Raymond, Jonathan Williams
Summary
This project is investigating the origin, abundance, and distribution of short-lived radioisotopes in the early Solar System, and other planetary systems, possibly from massive stars. Specific focus is on Al-26 and Fe-60 as they played an important role in the early thermal evolution of planetesimals.
Astrobiology Roadmap Objectives:
Project Progress
We evaluated four scenarios for the incorporation of the shortlived radionu-clide 26 Al from massive stars into circumstellar solids (represented in the Solar System by refractory inclusion in primitive meteorites). Injection into a gaseous disk during Class II protostellar evolution is highly unlikely (< 1%) to produce the canonical early Solar System abundance of 26Al. Models of scenarios in which massive stars pollute the remaining gas of the embedded cluster or a host giant molecular cloud with radionuclides, and hence laterforming stars, can generate abundances closer to the Solar System value if the time delay between star formation and solid condensation is a million years or less. Inclusion of BondiHoyle accretion increases the average abundance of Al in disks if star formation is simultaneous, but does not affect the estimated frequency of systems with an 26Al abundance like the early Solar System. Our models predict an initial abundance of exogenous 26Al in planetary systems from 0 to 26Al/ 27 Al ? 1E?4 . The ma jority, of systems receive no 26Al from massive stars because they formed before the most massive stars evolved away from the main sequence. A major uncertainty in all the models is the formation and transport of 26Albearing dust grains in winds or SN ejecta. Even if the primary mechanism of 26 Al production is, instead, irradiation by energetic particles from the central star, this source will also vary between stars by about two orders of magnitude. Planetesimals in disks with different abundances of 26Al will experience different thermal histories. If the position of the boundary between dehydrated and hydrated bodies, located at 2.5 AU in the Main Asteroid Belt, is set by the relative rates of accretion and the decay of 26Al, the location of this “waterline” will depend on the initial abundance of 26Al and affect the amount of water accreted by terrestrial planets in the habitable zone.
![Other Projects](https://webarchive.library.unt.edu/eot2008/20090825231026im_/http://astrobiology.nasa.gov/img/text/hd_other_projects_sa.gif)
- HANDBOOK OF STAR FORMING REGIONS
- A Rare low mass quadruple spectroscopic AND eclipsing binary
- A search for Main Belt Comets in Pan-STARRS 1
- A search for primordial water from deep in the Earth's mantle
- A spectroscopically unique Main Belt asteroid: 10537 (1991 RY16)
- A Supertree Analysis of the Metazoan Phylogeny
- Acquisition and Installation of a new Cameca ims 1280 ion microprobe
- Acquisition and Installation of Witec Confocal Raman microscope scanning system
- Amorphization of Crystalline Water Ice in the Solar System
- Assessing the likelihood of supernova impact of protoplanetary disks
- Carbonate Lithologies on Devon Island, Canada
- Chemistry and biology of ultramafic-hosted alkaline springs
- Chemistry of the NH3/H2O system
- DIVERSITY AND BIOGEOGRAPHY OF THE UNIQUE TROPICAL PHYLUM PLACOZOA
- Dynamical Evolution of Astroid Belt and the Parent Bodies of Iron Meteorites
- Ecology of a Hawaiian lava cave microbial mat
- FMARS Long Duration Mission: a simulation of manned Mars exploration in an analogue environment, Devon Island, Canada
- Formation and Detection of Hot-Earth Objects in Systems with Close-in Jupiters
- Formation and the Prospects of the Detection of Habitable Planets in Extreme Planetary Systems
- Formation of Molecular Hydrogen via Interaction of Ionizing Radiation with Hydrocarbon Ices in the Interstellar Medium
- Formation of Planetesimals in a Dynamically Evolving Nebula
- FU ORIONIS ERUPTIONS
- Ice Ages on Mars
- Ice at the Mars Phoenix Landing Site
- Ice on Main Belt Comets
- Icelandic subglacial lakes
- Mechanisms of Marine Microbial Community Structuring
- Mechanistical Studies on the Non-Equilibrium Chemistry of Unusual Carbon Oxide in Solar System Ices
- Modeling grain surface reaction pathways for large organic molecules
- Molecular Deuteration on grain surfaces
- NEWBORN BINARIES
- Observations and Models of comet 17P/Holmes
- Origin and Activation Mechanism of Main Belt Comets
- Origin of Irregular Satellites
- Recovery of comet 85P/Boethin for the Deep Impact Extended Mission
- Sediment-buried basement deep biosphere
- Serpentinazation and abiogenic methane in the Mariana Forearc
- Sleeping through the Arctic Martian Sol
- Spectropolarimetric studies of stars with hot jupiters
- TES study of intracrater low albedo deposits, Amazonis Planitia, Mars
- The delivery of short-lived radionucleides to the solar system
- The effect of lunar-like satellites on the orbital infrared lightcurves of Earth-analog planets
- The Main Belt distribution of basaltic asteroids
- The Size Distribution of Small KBOs
- THE VYSOS PROJECT
- Ultra-violet processing of ices in the Rosette Nebula
- Unveiling the evolution and interplay of ice and gas in quiescent clouds
- Variable Young Stellar Objects Survey (VYSOS)
- Water on Mars
- X-ray- and UV-bright low-mass stars in the solar neighborhood