October 2013 HAD Meeting Abstracts

All sessions and meetings in the Sheraton Denver Downtown Hotel.

HAD Invited Talks

Session #104: Monday, 7 Oct 2013, 8:30 a.m. Governor’s Square 17
Session Chair: Jay M. Pasachoff, Williams College.

8:30 1. Clyde W. Tombaugh, Discoverer of Pluto: A Personal Retrospective
David Levy, Vail, AZ.
This talk offers a retrospective of the life, times, and ideas of Clyde W. Tombaugh. One of the premier observers of the twentieth century, Tombaugh began observing as a teenager and was hired by the Lowell Observatory in Flagstaff, Arizona, in 1928, to resume and conduct the search for "Planet X", the world postulated by Percival Lowell, founder of the observatory. Tombaugh discovered this object on February 18, 1930, and it was subsequently named Pluto a few months later. Tombaugh's life following the discovery was busy, full, and sometimes difficult. He continued his search for about fifteen years, discovering five open clusters, one globular cluster, a new cataclysmic variable star, and likely the first known supercluster of galaxies. He also discovered a comet, but that find was not confirmed for 81 years until it was rediscovered by the Tenagra Observatories just a few months ago and named Comet Tombaugh-Tenagra. Tombaugh was as well known for his delightful sense of humor and fun as he was for his abilities as an observer. However it would be difficult to present such a talk without some mention of the concern and depression he endured at the end of his life about the changing status of his signature discovery. Ultimately, this presentation will try to offer a personal perspective of the man and the scientist I knew for the decades since I first heard him speak in 1963 until his death in 1997.

9:00 2. Gerard Kuiper and the Infrared Detector
Derek Sears, NASA Ames research Center and Bay Area Environmental Research Institute.
The life and contributions of Gerard Kuiper have been documented by Dale Cruikshank in his National Academy of Sciences biography. I will argue that particularly important in this eventful life was Kuiper's war time experiences. Kuiper's wartime role evolved as the war unfolded, but towards the end he was charged by the US military with reporting German progress with war-related technologies and the activities of scientists under Nazi control. He interviewed a great many scientists, including his own PhD mentor (Ejnar Hertzsprung), and when Kuiper was the only person available, he interviewed concentration-camp victims. He carried briefing sheets that identified the technologies being sought by the allies and the major fraction of these involved infrared equipment. He sent back to the USA boxes of documents, and large amounts of equipment, and he stressed to the military his interest in these for his own research. It seems very likely that in this way an effective PbS infrared detector, so critical to Kuiper's career and the future of planetary science, came to the USA and to Robert Cashman's laboratory at Northwestern University. As the war was winding down, Cashman and Kuiper worked together to develop a practical infrared spectrometer for astronomical use. Within months, Kuiper discovered the C0₂ atmospheres on Mars and Venus.

9:30 3. Rocks From Space: A Historical Perspective
Donald K. Yeomans, Jet Propulsion Laboratory.
The notion that rocks could fall to Earth from space was not seriously considered until the early nineteenth century. The impact origin of the lunar craters reached a scientific consensus only in the mid twentieth century and a wide understanding that the Earth’s neighborhood is crowded with millions of near-Earth asteroids that could cause impact damage to Earth is less than a few decades old. In the late seventeenth century, even such notable scientists as Robert Hooke and Isaac Newton ruled out the existence of small bodies in space. In 1794, the German physicist and father of acoustics Ernst F.F. Chladni published a short list of fireball events and effectively argued that these events and the meteorites they dropped could not have been atmospheric and were likely due to cosmic rocks entering the Earth's atmosphere. In 1802 the British chemist Edward Charles Howard showed that several meteoritic stones had similar chemical compositions and that nickel, which is seldom present in terrestrial rocks except in trace amounts, was common to all of them. These two pivotal works, along with a number of early nineteenth century falls, slowly strengthened the notion that fireball events and the stones they dropped were of celestial, rather than atmospheric, origin. Even so, it was well into the mid twentieth century before Meteor Crater in particular and the obvious lunar craters in general were widely considered as impact phenomena rather than being due to volcanic eruptions or steam generated explosions. It seems that despite Mother Nature's best attempts to point out the importance of impact events in the solar system and the existence of a vast population of near-Earth asteroids, much of the scientific community reached these viewpoints rather late. Likely reasons for this slow acceptance of rocks from space will be discussed.

10:00 a.m. End of session.

HAD Oral Contributed Papers

Session #108: Monday, 7 Oct 2013, 10:30 a.m. Governor’s Square 17
Session Chair: Derek Sears, NASA Ames Research Center and Bay Area Environmental Research Institute.

10:30 1. Budgeting for Exploration: the History and Political Economy of Planetary Science
Jason Callahan, The Tauri Group.
The availability of financial resources continues to be one of the greatest limiting factors to NASA’s planetary science agenda. Historians and members of the space science community have offered many explanations for the scientific, political, and economic actions that combine to form NASA’s planetary science efforts, and this essay will use budgetary and historical analysis to examine how each of these factors have impacted the funding of U.S. exploration of the solar system. This approach will present new insights into how the shifting fortunes of the nation’s economy or the changing priorities of political leadership have affected government investment in science broadly, and space science specifically. This paper required the construction of a historical NASA budget data set displaying layered fiscal information that could be compared equivalently over time. This data set was constructed with information collected from documents located in NASA’s archives, the Library of Congress, and at the Office of Management and Budget at the White House. The essay will examine the effects of the national gross domestic product, Federal debt levels, the budgets of other Federal agencies engaged in science and engineering research, and party affiliation of leadership in Congress and the White House on the NASA budget. It will also compare historic funding levels of NASA’s astrophysics, heliophysics, and Earth science efforts to planetary science funding. By examining the history of NASA's planetary science efforts through the lens of the budget, this essay will provide a clearer view of how effectively the planetary science community has been able to align its goals with national science priorities.

10:45 2. 211-Year-old Mystery Solved: Creator of the Word “Asteroid” Revealed
Clifford J. Cunningham, National Astronomical Research Institute of Thailand,.
In 1802, William Herschel famously declared that the newly discovered celestial objects Ceres and Pallas were asteroids, not planets. The term asteroid was rejected by nearly every astronomer in the early nineteenth century, but is now the most widely-used word to describe the small planetary bodies of the solar system. Even so, its origin has remained a mystery. By default, its creation has always been attributed to Herschel himself, but he lacked the knowledge of Greek and Latin to coin a new word to describe Ceres and Pallas. Herschel instead turned to a network of colleagues for advice. A study of contemporary manuscript evidence has now identified the name of the scholar who created the word asteroid.

11:00 3. The Planetary and Eclipse Oil Paintings of Howard Russell Butler
Jay Pasachoff, Williams College and Roberta J.M. Olson, New-York Historical Society.
The physics-trained artist Howard Russell Butler (1856-1934) has inspired many astronomy students through his planetary and eclipse paintings that were long displayed at the Hayden Planetarium in New York, the Fels Planetarium at the Franklin Institute in Philadelphia, and the Buffalo Museum of Science. We discuss not only the eclipse triptychs (1918, 1923, and 1925) at each of those institutions but also his paintings of Mars as seen from Phobos and from Deimos (with landscapes of those moons in the foreground depicted in additional oils hung at Princeton University) and the Earth from our Moon. We also describe his involvement with astronomy and his unique methodology that allowed him to surpass the effects then obtainable with photography, as well as his inclusion in a U.S. Naval Observatory eclipse expedition in 1918, as well as his auroral, solar-prominence, and 1932-eclipse paintings.

11:15 4. The Genesis of the Arecibo 305 m Telescope
Donald B. Campbell, Cornell University.
November 1 of this year marks the 50th anniversary of the inauguration of the 305-m Arecibo telescope in Puerto Rico. The concept for the telescope originated with then professor of engineering at Cornell University, William E. (Bill) Gordon, in the spring of 1958. Bill Gordon’s interest was in building an antenna/transmitter combination with sufficient sensitivity to detect Thompson scatter from the individual electrons in the Earth’s ionosphere and use this capability to investigate ionospheric parameters as a function of height, a technique that was dubbed incoherent scatter. A 1,000 ft (305 m) diameter antenna coupled with a 2.5 MW peak power transmitter operating at a frequency of about 400 MHz was settled on as the best fit to the requirements. Bill Gordon and his colleagues at Cornell realized that the capabilities of such an antenna would also be applicable to radar studies of the planets and to radio astronomy. A combination of Bill Gordon’s leadership, engineering talent at Cornell University, interest and support by the newly formed Advanced Research Projects Agency of the Department of Defense and the need for a better understanding of the ionosphere at the beginning of the space age let to the funding and initiation of the project in less than two years.

11:30 5. Microwave Remote Sensing of Planetary Atmospheres: The 50 Years from Mariner 2 to NASA-JUNO
Paul G. Steffes Georgia Institute of Technology.
In November 2012, the world celebrated the 50th anniversary of spacecraft-based exploration of planets and satellites other our own. The first successful interplanetary mission (Mariner 2) included the first spaceborne microwave radiometer for studying planetary atmospheres which measured the 1.3 and 2.0 cm emission spectrum of Venus (also known as the Cytherean spectrum), These measurements, plus accompanying earth-based observations of the centimeter-wavelength spectrum were used to establish early models of the composition and structure of Venus. Shortly thereafter, measurements of the microwave emission spectrum of Jupiter (also known as the Jovian spectrum) from 1.18 to 1.58 cm were conducted. In both sets of observations, wavelengths near the 1.35 cm water-vapor resonance were selected in hope of detecting the spectral signature of water vapor, but none was found. Thus the question remained, "where's the water?" The NASA-Juno mission is the first mission since Mariner 2 to carry a microwave radiometer instrument designed specifically for atmospheric sensing. It is expected to finally detect water in the Jovian atmosphere.

12:00 noon End of session.

HAD Poster Papers

Session #116: Monday, 7 Oct 2013, 3:30 to 6:00 p.m. Plaza Exhibit Hall

1. A Review of Historical Naked-Eye Sungrazing Comets
Matthew M. Knight, Lowell Observatory and John Hopkins University-Applied Physics Laboratory
With the upcoming perihelion passage of Comet ISON (C/2012 S1) in November 2013, there is considerable interest in sungrazing comets at present. However, given the infrequency with which such comets appear, there have been few systematic studies of their behavior near perihelion. Bright, sometimes even daytime-observable comets have been recorded by observers around the world for more than 2000 years. A number of authors have compiled records of possible historical sungrazing comets, e.g., Hasegawa 1979, Kronk 1999, Hasegawa & Nakano 2001, England 2002, and Strom 2002. We review this literature to estimate the frequency of arrival of naked-eye sungrazing comets and investigate if there are any trends in their behavior, such as between peak brightness and length of time a comet is observable. We will also review the “modern” observations of naked-eye sungrazing comets (primarily Kreutz group comets observed since 1800) to investigate the frequency of fragmentation near the Sun and the dependence of survivability on size (as inferred from brightness) and/or perihelion distance.