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Executive Summary

This year has been an extremely productive year for the Arizona NAI team. We have not only had significant progress in instrumentation and research but have made great advances in administrative and collaborative areas within our local community, within NAI, nationally and internationally.

Collaborations

In July 2005, the Arizona Board of Regents approved the establishment of the Life and Planets Astrobiology Center — LAPLACE — establishing a formal commitment to the pursuit of astrobiology and its primacy in research activities. This LAPLACE complements and overlaps with the entity within the NAI team structure, also known by the acronym LAPLACE. This center within the University of Arizona (UA) system will provide the administrative means to expand our study of astrobiology to complement the astronomical focused NAI team. Additionally, the UA’s College of Science hired its first astrobiology-designated faculty position under LAPLACE. Alex Pavlov (an NAI Ph.D. product) will begin his work at UA in January 2006.

LAPLACE has had a year of growing collaborative efforts within the local community and throughout the astrobiology community. Members of LAPLACE have been invited to participate in seminars and other forums at many institutions and these have included NAI Director’s Seminars by Jonathan Lunine and Michael Meyer. Lunine was Program Director and Chris Impey and Nick Woolf were faculty members of the Vatican Observatory 2005 Summer School in Observational Astronomy and Astrophysics, its topic was Astrobiology: The Search for our Origins and Life Elsewhere. This school promotes the education of students from the developing world and funds their study at Castel Gandolfo Italy for four weeks in June. [http://clavius.as.arizona.edu/vo/R1024/VOSS2005.html].

LAPLACE has also been involved with the Astrobiology and the Sacred: Implications of Life Beyond Earth project at UA [http://scienceandreligion.arizona.edu/fellows.html]. We have participated in the lecture series and sponsored several of the visiting speakers. [A list of colloquia at UA and by LAPLACE researchers is submitted with this report]. In addition, the theme of our Biology/Medicine/Agriculture BIO5) symposium this year was Astrobiology.
Further, we have participated in meetings of a U Arizona group on Quantitative Biology.

Collaboration with other NAI teams continued this fiscal year. In 2004 Carol Oliver of the Australian Centre for Astrobiology visited to work with the Education and Public Outreach researchers in Steward Observatory at UA. During her visit, she met with the LAPLACE team as part of one of its monthly group meetings to brief us on working with the media more effectively. Graduate researchers Danial Apai and Murray Silverstone participated in the NAI FAR seminar series with Apai serving on the organizing committee. Additional faculty members with Arizona team members in the Vatican Observatory Summer School were Baross and Sullivan from the NAI Washington team, part of a continuing Arizona-Washington collaboration. Woolf has participated in a joint NAI/TPF meeting to discuss Biomarkers, with Meadows, Crisp, Des Marais, and Kasting as well as additional Terrestrial Planet Finder (TPF) user group and SWG members.

In March 2005 LAPLACE hosted students from the University of Washington and non-astronomy departments of the University of Arizona for a five-day hands-on observing course on UA campus and at Kitt Peak National Observatory. The materials and format of this exchange was so successful that the UA Astronomy Camp used portions during their summer program 2005 and LAPLACE will implement a similar program open widely to graduate students in January 2006. The second phase of the exchange will occur in Fall 2005 when LAPLACE students and faculty travel to UW to learn about the biology aspect of astrobiology.

Finally, in our effort to bring astrobiology into the science departments at University of Arizona, the team has provided resources to bring in colloquium speakers, William Klemperer for both Astronomy and Chemistry colloquia, Steve Benner for a Chemistry colloquium and Gerry Joyce for a colloquium in Molecular and Cellular Biology.

The interest in astrobiology throughout the college of science has resulted in additional talks supported by the departments, for example Biochemistry had a colloquium by Robert Blankenship, and the BIO5 collaboration between Life Sciences and the Medical College had a one day symposium that included talks by Jack Szostak, Steve Benner and Jonathan Lunine.

Research

Module 1: The Building Blocks of Life succeeded in many areas during the year — in the lab, observationally and collaboratively. Aldo Apponi in the module completed construction of a pulsed molecular-beam Fourier transform microwave spectrometer. Results of analysis doubled the microwave data set for microwave spectrum of acetol. Researchers completed survey results of molecular cloud Sgr B2(N) cover about half of the 2 and 3 mm (70 — 170 GHz) spectrum absolutely confirmed the identification of the interstellar molecules glycolaldehyde, vinyl alcohol and ethylene glycol; tentative detections of propenal and propanal have been made.
Calculations performed on conformational behavior of sugars (ribose) showed multitude of structural isomers of these systems that differ little in terms of their stability. Observations of comets, Q4/NEAT and T7/LINEAR detected H₂CO towards both these comets at 1mm.
Module 1 scientists completed a study of ¹²C/¹³C ratios using the N=1_0 transition of CN produced results from CN are in reasonable agreement with previous ratios established independently from CO and H₂CO. This module’s work expanded collaborations within the University of Arizona between the astronomy and chemistry departments.

Module 2: Formation and Evolution of Habitable Worlds

This module aims to use observations of the gas and dust in (a) planet-forming accretion disks surrounding young stars; and (b) debris disks surrounding more mature stars to understand key steps and timescales in the formation of planetary systems and their evolution, and to constrain outcome planetary system architectures. Another objective of the module is to provide candidate targets for direct detection and characterization of planets.

Researchers used various telescopes, both ground- and space-based to further our understanding of habitable worlds. Joan Najita calculated the thermal-chemical structure of the gaseous atmospheres of the inner disks of accreting solar-like pre-main sequence stars then used these to predict the relative column densities of key molecular tracers used to characterize the gas content of PMS star disks. Detection of apparently abundant gas clearly lying within the apparent opacity hole — perhaps indicates an absence of small (r < 1 micron) grains in the inner disk Results from the Spitzer Space Telescope continue to inform our research program within Module 2. One of the striking Spitzer results has been the deviation from a steady decrease of dust with age of system, as in observations of HD12039, a rare 30 million year old star with a mid-infrared excess of emission by warm dust. These seem likely caused by rare early collisions between planetismals or late collisions between asteroids. In a related study, Steve Strom, Renu Malhotra, Toshi Ito, and David Kring (2005) argue that the late-heavy bombardment in the inner solar system was due in part to an influx of asteroids created through migration of the giant planets -- with profound effects predicted dust generation rates in debris disks observed, and so there would not have been an earlier heavy impact phase, and the origin of life could possibly be moved back to 4.4 Gya. Najita and Williams' results of the 850 micron James Clerk Maxwell Telescope/ bolometer array survey suggest that the mass in small grains declines significantly on a ~200 Myr timescale. Paola D'Allessio et al. model accounting for the Spitzer Space Telescope Infrared Spectrogarph observations of CoKu Tau/4's "transition disk".

Module 3: Nature of Planetary Systems

Direct detection for extrasolar planets is fast becoming a reality, and LAPLACE is well-poised to be in the forefront of this new area of research. Using multiple techniques researchers in this module are now in the process of carrying out surveys for young planets as well as developing new techniques which will push our sensitivity to older planets around more nearby stars. Module 3 work has developed new instrumentation to detect these planets, begun surveys using existing adaptive optics techniques and furthered modeling work to enable the interpretation of detections from a range of observatories, including, the Hubble Space Telescope (HST), Spitzer Space Telescope, and the James Web Space Telescope (JWST). This work is laying the foundation for understanding what other stellar systems may be hospitable to life and how we identify such systems. One of the most exciting discoveries was the discovery of close companion to AB Dor using Simultaneous Differential Imaging and the determination that current theoretical models overestimate the brightness of substellar objects at young ages.
Researchers have been working on improved sensitivity of MMT adaptive optics system to allow detection of planets of significantly smaller masses than other systems. Finally Burrows completed of comprehensive invited review for Nature by Adam Burrows that provides the best theoretical guide for the search for planets outside the Solar System.

EPO

The EPO effort on teaching teachers, and exploring conceptual difficulties of students has been making excellent progress as detailed in the separate report of the team. Here, special attention is paid to two collaborative projects, first in the University of Washington graduate student visit.
The problems for transferring information across disciplines has some resemblances to the problems experienced with non-major undergraduates. We were therefore very appreciative of help from Dr. Tom Olien in the UW graduate student visit, where he participated in the teaching.

Secondly, the talks in the Astrobiology and The Sacred series has been used by the EPO team as an opportunity for continuing education of teachers. The teachers have both had special meetings with the speakers, and have been helped in preparation for the talks by the EPO team.

Future Plans

LAPLACE will continue to expand its collaborative efforts within local communities and internationally. Now that the Arizona Board of Regents has made LAPLACE an official center, one of our goals is to expand our teaching role, and in particular to organize the possibility of Astrobiology minors for Ph.D. programs. As part of the planning for this, Woolf will be visiting the University of Washington, to study how their astrobiology teaching program works, since it seems to have been the most successful to date.

We are currently planning the January 2006 Winter School in Astrobiology, where we intend to have 20 astrobiology students from other institutions and five from Arizona. We see this as the optimal number of students for the observing experience we can provide at Kitt Peak.

Among the new developments related to Astrobiology has been the casting of the first 8.4m mirror for the Giant Magellan Telescope, a 20m class optical/infrared telescope with a light gathering power 19 times the Palomar Telescope [http://www.gmto.org/]. A workshop to discuss the possibilities for observing extrasolar planets with this telescope is being organized with the Carnegie Institution of Washington astrobiology group.

Plans for research collaboration beyond the Arizona group is progressing, Arizona (L. Ziurys) has submitted a program “Follow the Carbon” with external collaborators S. Benner, D. Brownlee, S. Pizzarello, to explore the transportation of carbon from its sources into the solar system and the Earth, to explore its molecular modifications, and to study the possible processes whereby modestly changed material may have been available for the origin of life on Earth, either as a catalyst, or as a complex ingredient ahead of the development of catabolic pathways.