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Near-Earth Objects Finding Them Before They Find Us. Don Yeomans NASA/JPL. 2. What are Near-Earth Objects?. Comet Hartley 2, Nov. 4, 2010. Comets (Weak and very black icy dirt balls) Weak collection of talcum-powder sized silicate dust
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Near-Earth Objects Finding Them Before They Find Us Don Yeomans NASA/JPL
2 What are Near-Earth Objects? Comet Hartley 2, Nov. 4, 2010 • Comets (Weak and very black icy dirt balls) • Weak collection of talcum-powder sized silicate dust • About 30% ices (mostly water ice) just below surface dust. CO2 ices also present further below surface. • Fairly recent resurfacing and few impact craters • Asteroids (run the gamut from wimpy ex-comet fluff balls to slabs of iron • Most are shattered fragments of larger asteroids • Rubble rock piles - like Itokawa • Shattered (but coherent) rock - like Eros • Solid rock • Solid slabs of iron like Meteor crater object Itokawa Itokawa
1800 1800 3 History of Known NEO Population Earth Crossing Outside Earth’s Orbit Armagh Observatory
1800 1800 1900 4 History of Known NEO Population Earth Crossing Outside Earth’s Orbit Armagh Observatory
1800 1800 1900 1950 5 History of Known NEO Population Earth Crossing Outside Earth’s Orbit Armagh Observatory
1800 1800 1900 1950 1990 6 History of Known NEO Population Earth Crossing Outside Earth’s Orbit Armagh Observatory
1800 1800 1900 1950 1990 1999 7 History of Known NEO Population Earth Crossing Outside Earth’s Orbit Armagh Observatory
2012 The Inner Solar System in 2006 • Known • 600,000 • minor planets • 9450 NEOs • 1350 PHAs 1800 1800 1900 1950 1990 1999 Scott Manley 8 History of Known NEO Population Earth Crossing Outside Earth’s Orbit Armagh Observatory
9 The Importance of Near-Earth Asteroids • Science • Future Space Resources • Exploration • Planetary Defense
11 Human Accessible Targets
12 JPL’s SENTY NEO Risk Page http://neo.jpl.nasa.gov/risk/
LINEAR 13 NASA’s NEO Observation Program NEO-WISE Pan-STARRS Catalina Sky Survey
Radar Studies 14 Goldstone, CA Arecibo, Puerto Rico Study of Shape, Size, Motion and mass of near-Earth object 66391 (1999 KW4) Shape, Size of 6489 Golevka
15 NASA’s NEO Program Office at JPL • Automatic orbit updates • Are any of the NEOs a threat? • Relational database • Study deflection strategies • Additional Information • Impact warnings & outreach • http://www.jpl.nasa.gov/asteroidwatch/ • Widget available giving next 5 Earth close approaches • NEO Program Office: http://neo.jpl.nasa.gov/
16 Recent NEO Program Office Activities • Human Exploration Target Body Identification • Which NEAs are desirable RT mission targets? • When are they next observable (optical & radar)? • Deflection mission study for asteroid 2011 AG5 IP = 1/500 for Feb. 5, 2040 • Educational site for designing asteroid deflection missions.
17 2011 AG5
20 Near-Earth Asteroid Apophis Predicted Close Approach of Apophis (~270m Object) on April 13, 2029 CLOSE-UP VIEW Geosynchronous Orbit
21 Near-Earth Asteroid 2012 DA14 in Feb. 2013
23 Asteroid 2012 DA14 February 15, 2013 2012 DA14
24 Deep ImpactComet Tempel 1 on July 4, 2005
25 Comet ISON
26 Observing Comet ISON