"Does David Morrison believe that Man evolved from apes, according to the popular theory of evolution."
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The delivery of short-lived radionucleides to the solar system
Project Investigators: Eric Gaidos
Other Project Members
Jonathan Williams (Collaborator)Summary
I have studied various astrophysical scenarios for the delivery of short-lived radionucleides to star forming cores and planet forming disks in order to explain the observed abundances of 26-Al and 60-Fe in primitive meteorites. The latter, in particular, implies the birth of our solar system closely followed the death of a massive star. It is hard to reconcile the astrophysical and cosmochemical pictures but the most likely birth environment of our Sun was in a giant molecular cloud that formed several generations of stars.
Astrobiology Roadmap Objectives:
- Objective 1.1: Models of formation and evolution of habitable planets
- Objective 4.3: Effects of extraterrestrial events upon the biosphere
Project Progress
The discovery that the short-lived radionucleide, 60-Fe, was present in the oldest meteorites suggests that the formation of the Earth closely followed the death of a massive star. I have been studying different mechanisms for the delivery of 60-Fe and other short-lived radionucleides to the solar system. This work resulted in one paper published in the Astrophysical Journal (Williams & Gaidos 2007) and I was invited to lecture on the subject at a winter school on planet formation in France in early 2008. The lecture is available on the web at http://www-laog.obs.ujf-grenoble.fr/heberges/Houches08/index.htm and has been written up for publication in the workshop proceedings. I conclude that there are few ways to reconcile the astrophysical and cosmochemical pictures but the most likely is that the Sun formed in a large cluster of stars in a massive molecular clump (about 10,000 solar masses and several parsecs in size) on or near the boundary of an HII region. An example of such a situation is in the Rosette molecular cloud where I find more than half the protostars lie close enough to the most massive stars that they could incorporate supernova ejecta were it to explode at the current time (see figure). The delivery of 60-Fe is also likely accompanied by the delivery of 26-Al, a more abundant short-lived radionucleide that has a significant effect on the thermal history of planetesimals and potentially the snowline in a proto-planetary disk. Eric Gaidos is leading the effort on this related subject.
Gas and stars in the Rosette. The red color is an image of the ionized gas emission powered by the radiation from high mass stars. These supernova progenitors are shown as white star symbols. Young stars with ages less than 3 Myr are shown as white dots. The blue and green show the distribution of CO and 13CO respectively and reveal a giant molecular cloud. Individual regions that are both close enough to a massive star and dense enough to collapse rapidly to deliver large quantities of 60-Fe to planet forming material is shown by the white circles. This demonstrates that more than 50% of the young stars in the cloud could potentially be contaminated by supernova ejecta.Mission Involvement
Herschel Space ObservatoryI am the NASA PI on a Herschel Open Time Key Program (OTKP) to measure the gas content in protostellar disks via far-infrared spectroscopy. This project will help constrain the timescale for planet formation, a critical parameter in understanding the delivery of short-lived radionucleides to the solar system.Publications
Williams, J.P. & Gaidos, E. (2007). On the likelihood of supernova enrichment of protoplanetary disks. Astrophysical Journal, 663(1):L33-L36 [Online].
- 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