P.O. Box 1184, Greenbelt, MD 20768-1184
|September 2016||http://graa.gsfc.nasa.gov||32nd Year of Publication|
|September 13||Mark your calendar for the GRAA Luncheon at 11:30 a.m. at the Greenbelt American Legion Post #136 at 6900 Greenbelt Road. Reservations are required for our venue, so please contact Alberta Moran on her cell phone at 301-910-0177 or via email at firstname.lastname@example.org not later than noon on Friday, September 9th. Our featured speaker will be Dr. James Garvin, Goddard’s Chief Scientist, whose presentation topic is “The Engineering of Science at NASA’s Goddard Space Flight Center.”|
|October 11||Mark your calendar for the GRAA Luncheon at 11:30 a.m. Dr. Lori Glaze, Deputy Director of Goddard’s Solar System Exploration Division in the Sciences and Exploration Directorate. Her presentation topic will be the “Deep Atmosphere Venus Investigation of Noble gases. Chemistry, and Imaging (DAVINCI)” mission, for which she is Principal Investigator.|
COMMENTS FROM TONY COMBERIATE, GRAA PRESIDENT: Our August luncheon speaker was Dr. Donald Jennings, an Astrophysicist in Goddard’s Detector Systems Branch. His presentation was entitled “Goddard’s Linear Etalon Imaging Spectral Array (LEISA) Instrument on the New Horizons Mission.” Don described historical research about Pluto since it was first discovered by Clyde Tombaugh in 1930 through the recent encounter by the New Horizon’s spacecraft on July 14, 2015. Tombaugh used predictions from Percival Lowell (1915), who first caught hints of Pluto’s existence by observing its effect on other planets’ orbits. In 1978, James Christy discovered a “bump,” which turned out to be a moon passing in front of the planet. As more data became available over the years, estimates of the mass of Pluto diminished and it was reclassified as a dwarf planet in 2006, the year the New Horizons mission was launched. New Horizons got a gravity assist from a fly-by of Jupiter in 2007 and then encountered Pluto in July 2015 after flying over 3 billion miles.
Don described the Goddard-built instrument LEISA, which together with the Multispectral Visible Imaging Camera (MVIC) comprise Ralph, the visible and infrared camera on New Horizons. LEISA is a linear variable filter camera operating in the 1.25 to 2.5 micron spectral region with resolution as high as 7 km/pixel at the closest approach to Pluto. It was designed to identify and map surface ices, thus leading to several discoveries in the Pluto system. His presentation included some of the incredible images from the encounter and a description of the many discoveries the mission uncovered. For example, the mission mapped ices of methane, water, carbon monoxide and nitrogen across Pluto’s surface. Pluto is covered primarily with methane, but has a large white area coated with carbon monoxide ice. Pluto’s largest moon, Charon (named in part for James Christy’s wife, Charlene), is about half the size of Pluto and is covered with water ice with trace amounts of ammonia ice. Two of the smaller moons have turned out to be almost pure water ice. During the encounter, Pluto’s diameter was measured at 1,473 miles, or about two thirds the diameter of Earth’s moon. It has less than half the density of the Earth and does not bulge at the equator.
Following the Pluto encounter, New Horizons has been sending the high resolution image and spectral data back to Earth, a process that is taking more than a year due to the great distance. The latest images and other information can be found on both the NASA website (https://www.nasa.gov/mission_pages/newhorizons/main/) and Johns Hopkins Applied Physics Laboratory (where the spacecraft was built) website (http://pluto.jhuapl.edu). Next up, the New Horizons mission has been extended to fly by a second Kuiper Belt object (2014 MU69, discovered by the Hubble Space Telescope), which it is expected to encounter in January 2019.
TREASURER’S REPORT: Treasurer Jackie Gasch received tax-deductible contributions from the following members: Richard Baker, Arthur Fuchs, James Gray, Arlin Krueger, David Manges, William McGunigal, Ralph Mollerick, and Thomas Underwood.
FROM THE GODDARD ARCHIVES – IT HAPPENED IN SEPTEMBER: Space Shuttle Discovery (STS -48) was launched from Cape Canaveral, FL, on September 12, 1991, and deployed the Upper Atmosphere Research Satellite (UARS) on September 15th at an altitude of about 375 miles. As the first satellite dedicated to studying stratospheric science, UARS focused on the processes that lead to ozone depletion and also measured winds and temperatures in the stratosphere as well as energy input from the Sun. While intended to be a three-year mission, six of its 10 instruments functioned for 14+ years. UARS was decommissioned in December 2005 due to funding cuts. Re-entry occurred between 300 and 800 miles downrange from American Samoa on September 24, 2011.
REMEMBERING OUR FORMER COLLEAGUES:
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS) SEEKS VOLUNTEERS: The AAAS needs volunteer scientists, engineers, and mathematicians to assist K-12 Science, Technology, Engineering, and Mathematics (STEM) teachers in the Washington, DC Metropolitan Area during the 2016-2017 school year. Details of the collaboration are worked out between the teacher and volunteer, and may involve giving demonstrations, assisting in lab experiments, lecturing on special topics, assisting with homework, etc. Hours are flexible and volunteers attend a one-day training session in September before being assigned to schools. If members care about K-12 STEM education and have an interest and time to share your knowledge with students and teachers in this worthwhile endeavor, please call Betty Calinger at 202-326-6629 or send her an email soon at email@example.com for details and learn more about this AAAS outstanding outreach program.
THOUGHT FOR SEPTEMBER: Relationships are akin to algebra. For example, have you ever thought about your X and wondered Y?