60TH ANNIVERSARY OF NASA
NASA Science: At Work in an Endless Frontier
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n January 2015, attendees at the 225th meeting of the American Astronomical Society were among the first to see retro-style travel posters (available for download on the internet) inviting visitors to see the sights of “Kepler-186f, Where the Grass Is Always Redder on the Other Side,” or “Relax on Kepler-16b, The Land of Two Suns Where Your Shadow Always Has Company,” or perhaps to “Experience the Gravity of HD 40307g – A Super Earth.” These fanciful renderings of alien planets by NASA Jet Propulsion Laboratory visual strategists Joby Harris and David Delgado were based on discoveries by the agency’s Kepler Space Observatory, launched in 2009, of the first validated Earth-sized planet to orbit a distant star in the habitable zone (Kepler-186f), and a planet that, like Tatooine in the movie Star Wars, orbits two stars (Kepler-16b) but would not be suitable for Luke Skywalker because it has a temperature similar to dry ice (-109°F); as well as by groundbased observatories of a planet eight times more massive than Earth where skydiving would be a thrilling endeavor (HD 40307g). What’s remarkable about the Kepler observatory and its discovery of 2,652 confirmed exoplanets along with a further 2,737 unconfirmed planet candidates as of September 2018, is that until 1992, not a single planet had been found outside our solar system. More broadly, Kepler is representative of a NASA science enterprise that through its Science Mission Directorate has more than fulfilled the expectations of the nation at the time of the agency’s founding, when President Dwight D. Eisenhower observed “a developing space technology can … extend man’s knowledge of the Earth, the solar system, and the universe.”
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A Quarter Century of Achievement
Thanks to NASA’s science enterprise, in the last 25 years alone, the space agency has made huge strides in advancing astrophysics, planetary exploration, heliophysics, and Earth science. Among NASA’s greatest science hits are: • The launching, repair, and operations of the Hubble Space Telescope well beyond its planned operating life, leading to fundamental discoveries about the size and age of the universe, the existence of supermassive black holes at the centers of galaxies, the galactic environments in which quasars reside, and the processes by which stars form. • The Cosmic Background Explorer Satellite (COBE), whose work in validating the Big Bang theory of the universe earned NASA senior astrophysicist and project scientist John Mather the 2006 Nobel Prize for Physics, which he shared with George F. Smoot. • The operations on Mars of the Sojourner (1997), Spirit (2003-2010), Opportunity (2003-present), and Curiosity (2011-present) exploration rovers, which have helped characterize the red planet’s geography and document evidence of water in Mars’ ancient history. • The orbiting of Saturn by the NASA-European Space Agency and Italian Space Agency Cassini spacecraft (2004-2017), leading to the discovery of three new moons (Methone, Pallene, and Polydeuces) and observations of water ice geysers erupting from the south pole of the icy moon Enceladus, and the placement of the Huygens probe on the surface of Saturn’s moon Titan (2005). • The placement at the Earth-sun Lagrangian (L1) point of the NASAEuropean Space Agency Solar and Heliospheric Observatory (SOHO)
IMAGE BY NASA, ESA, J. DALCANTON, B.F. WILLIAMS, AND L.C. JOHNSON (UNIVERSITY OF WASHINGTON), THE PHAT TEAM, AND R. GENDLER
By Edward Goldstein
