AGENDA Greetings from GTCC...............................................................................Dr. Randy Parker President, GTCC Welcome ...........................................................................................................Aaron Martin Cline Observatory Founding Director Introduction of Speaker.....................................................................................Tom English Director, Cline Observatory Speaker..................................................................................................Dr. Sean C. Solomon Director, Lamont-Doherty Earth Observatory, Columbia University Presentation: The MESSENGER Spacecraft Mission to Mercury: Surprises from the Innermost Planet There will be a short question period at the end of the talk. Please wait to leave the auditorium until after the question session. If you need to leave early, please use the doors at the rear of the auditorium. You are invited to the public viewing session at Cline Observatory following the conclusion of the program (weather permitting). The MESSENGER Spacecraft Mission to Mercury: Surprises from the Innermost Planet Mercury, the smallest and innermost solar system planet and the planet formed from the densest materials, remained comparatively unexplored for more than three decades following three flybys by the Mariner 10 spacecraft in 1974–75. Space exploration of Mercury resumed with the selection for flight, under NASA’s Discovery Program, of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. Launched in 2004, MESSENGER flew by the innermost planet three times in 2008–2009, was inserted into orbit about Mercury in March 2011, and operated until propellant was exhausted in April 2015. MESSENGER’s chemical remote sensing measurements showed that Mercury has a low-iron surface composition that differs from those of the other inner planets. Moreover, surface materials are richer in volatile constituents – those that would be removed by high temperatures – than predicted by most planetary formation models. Global image mosaics and targeted high-resolution images reveal that Mercury experienced globally extensive volcanism, including large expanses of plains erupted as flood lavas and widespread examples of pyroclastic deposits emplaced during explosive eruptions of volatile-bearing magmas. Bright deposits within impact craters host fresh-appearing, rimless depressions or hollows, often with high-reflectance interiors and halos; such hollows likely formed through the geologically recent loss of one or more volatile compounds. On the basis of imaging, neutron spectrometry, near-infrared reflectance, and thermal models derived from measured topography, Mercury’s polar deposits first detected with Earth-based radar consist largely of water ice in permanently shadowed cold traps within polar impact craters. In most locations, the water ice is covered with a 10–30-cm-thick layer consisting of a low-reflectance volatile stable to temperatures somewhat higher than water ice and likely consisting of impact-derived organic material.
SEAN C. SOLOMON Director, Lamont-Doherty Earth Observatory; Associate Director for Earth Systems Science, Earth Institute; and William B. Ransford Professor of Earth and Planetary Science, Department of Earth and Environmental Sciences, Columbia University Sean Solomon is the Director of Lamont-Doherty Earth Observatory, the largest of the research centers in Columbia University’s Earth Institute. Prior to arriving at Columbia, in July 2012, Solomon served for 19 years as Director of the Carnegie Institution’s Department of Terrestrial Magnetism in Washington, D.C., where his research focused on planetary geology and geophysics, seismology, marine geophysics, and geodynamics. From 1972 to 1992, Solomon was a member of the faculty of the Department of Earth, Atmospheric, and Planetary Sciences at the Massachusetts Institute of Technology. He has led or been involved in oceanographic expeditions on Earth as well as spacecraft missions to the Moon, Venus, Mars, and Mercury. From 1996 to 1998, he was President of the American Geophysical Union, the world’s largest organization of Earth and space scientists. He is a graduate of the California Institute of Technology (1966) and MIT (Ph.D., 1971). Solomon is the Principal Investigator for NASA’s MESSENGER mission to Mercury, the planet closest to the Sun. The MESSENGER spacecraft was inserted into orbit about Mercury in March 2011 after traveling for nearly seven years through the inner solar system, and it continuously mapped the planet’s surface, interior, and environment from shortly after arrival until the end of orbital operations in April 2015. From 1998 to 2008, Solomon served on the Executive Council of the NASA Astrobiology Institute, which seeks to understand how life on Earth arose and its potential to exist elsewhere. Solomon is a Co-Investigator on NASA’s GRAIL mission to the Moon, which launched in 2011 and mapped the Moon’s gravitational field in unprecedented detail. From 1982 to 2005, he was a Co-Investigator on both the Magellan mission to Venus and the Mars Global Surveyor mission. Solomon is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. Among his awards are the Geological Society of America’s G. K. Gilbert Award for solving broad problems in planetary geology, and the American Geophysical Union’s Harry H. Hess Medal, given for outstanding research on the evolution of Earth and other planets. In 2011, when he stepped down as a director at Carnegie, colleagues arranged to have a previously discovered asteroid named after Solomon. Asteroid 25137 Seansolomon, about a mile and half wide, is currently orbiting the Sun between Mars and Jupiter. Last year, Solomon was awarded the National Medal of Science by President Obama. Solomon was born and raised in Los Angeles and now lives in New York City. He and his wife Pamela have four children and eight grandchildren.
TONIGHT’S LECTURE IS DEDICATED TO THE MEMORY OF JO CLINE Jo Cline was born Joann Schlagenhauf in Bluffton, IN, and moved to North Carolina in 1948. She lived most of her life in Greensboro, and was a loving partner with her husband, Don, in business, ballooning, education, and philanthropy. She owned the BalloonPort of Greensboro and actively managed it for more than 30 years. Jo was a co-founder of the Pisgah Astronomical Research Institute (PARI) in the NC mountains, where she is lovingly remembered as “The First Lady of PARI.” The generosity and support of Don and Jo Cline helped make the observatory and the astronomy outreach program at GTCC possible, and they have left their mark on numerous astronomical and scientific institutions around North Carolina. The Clines have been fixtures at GTCC astronomy events during the past two decades, and could always be seen in the front row at our fall lectures. Jo’s quiet personality, along with her dry and sharp wit, will be deeply missed. The Ring Nebula image at right was taken by Jo when she took the AST 251 class at GTCC shortly after the observatory opened. Jo Cline Memorial Endowment Don Cline has established the Jo Cline Memorial Endowment at the GTCC Foundation, with a goal of raising $50,000 to support our fall astronomy speaker series, naming it in Jo’s honor. Don will match, dollar for dollar, contributions made to this fund until our goal is reached. Please consider honoring Jo’s memory by contributing to the fund – visit the Friends of the Observatory link at observatory.gtcc.edu, or use the attached tear-off information to send your contribution to the GTCC Foundation. Visit http://observatory.gtcc.edu/jo-cline-memorial-endowment/ to make your donation.