391:, Ostro noted that while the asteroid impact hazard is a long-term risk to any civilization, the risk associated with maintaining an active deflection program is higher, because it is just as easy to deflect an asteroid to impact Earth as to prevent it from doing so. Ostro advocated for continued funding of the
469:– one of the first binary near-Earth asteroids known. The shape of the primary (alpha) has been determined by inversion of radar images. This enabled studies of the orbital evolution of the secondary (beta), which is in turn coupled to the system's orbit around the Sun by
371:, producing the first resolved radar images of an asteroid, which they later used to construct a model of the object. Following the further development of imaging and shape reconstruction techniques by Ostro, Hudson, and Christopher Magri, and the upgrade of
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356:. Beginning in the early 1980s, Ostro led the development of radar imaging and shape-reconstruction techniques, first determining only outer limits of targets' shapes, then deriving three-dimensional shape models.
202:. Ostro led radar observations of numerous asteroids, as well as the moons of Jupiter and Saturn, Saturn's rings, and Mars and its satellites. As of May 2008, Ostro and his collaborators had detected 222
858:
546:, have refined knowledge of their orbits and show that their surfaces are coated with very low density (~1 g/cm) material, most likely fine-grain dust, to a depth of several meters.
883:
221:
He died
December 15, 2008, due to complications related to cancer. He has been remembered fondly by his colleagues for both his personal and professional contributions.
526:. In many cases, radar astrometry has excluded possible Earth impacts from trajectory predictions years before optical astrometry would have been able to do so.
843:
336:, also known as 1999 KW4, a binary near-Earth asteroid observed by Ostro and his collaborators. This shape model was obtained by inversion of radar images.
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431:– the first near-Earth asteroid imaged well enough to determine its shape, which is two distinct 0.9 km lobes in contact (a contact binary).
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To explore the dynamical implications of these observations in detail, Ostro collaborated with Steven
Chesley, Jon D. Giorgini,
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387:, placing particular emphasis on the need to characterize asteroids before any deflection attempt. In a paper with
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The
Structure of Saturn's Rings and the Surfaces of the Galilean Satellites as Inferred from Radar Observations
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Radar provides extremely accurate measurement of the positions and velocities of target objects, and such
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Ostro, S.J.; et al. (1988). "Asteroid shapes from radar echo spectra: A new theoretical approach".
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Ostro worked on radar observations of the icy satellites of
Jupiter and Saturn, particularly with the
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from observations by Ostro's group have been essential to predicting
Apophis' trajectory.
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798:. Division for Planetary Sciences. The American Astronomical Society. Archived from
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417:– the first near-Earth asteroid confirmed to be metallic. The estimated amount of
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Ostro, S.J.; Sagan, Carl (1994). "Cosmic collisions and galactic civilizations".
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Ostro, S.J.; et al. (1979). "Radar observations of asteroid 1 Ceres".
489:– an approximately 1 km wide asteroid with a possible Earth impact in 2880.
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190:(March 9, 1946 – December 15, 2008) was an American scientist specializing in
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in the mid-1990s, the number of radar observations increased dramatically.
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in 1984. Ostro headed JPL's
Asteroid Radar group, and was a member of the
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of near-Earth objects has been recognized as crucial to dealing with the
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41:
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348:, radar observations of asteroids were restricted to measurements of
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580:
NASA Medals for
Exceptional Scientific Achievement (1991 and 2004)
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450:– a large near-Earth asteroid that rotates exceptionally slowly.
195:
864:
Massachusetts
Institute of Technology School of Science alumni
340:
Much of Ostro's career focused on the development of asteroid
305:
344:. In early experiments, such as the first radar detection of
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796:"Ostro was the recipient of the 2003 DPS Kuiper Prize"
421:-group metals in 1986 DA is comparable to that in the
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RADAR instrument. Radar observations of Mars' moons,
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Ostro was an early participant in discussion of the
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483:(radiation force changing the orbit) was measured.
296:After completing his graduate work and a year in
859:Cornell University College of Engineering alumni
281:and studied the radar scattering properties of
495:– a near-Earth asteroid that will pass within
359:From August 19 to 22 of 1989, Ostro and
316:. In 2008, Ostro was elected a Fellow of the
8:
399:Notable asteroids observed by Ostro include
40:
29:
884:Fellows of the American Geophysical Union
395:, on both hazard and scientific grounds.
304:of astronomy at Cornell before moving to
425:, the largest source on Earth's surface.
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273:in 1978. At MIT, Ostro was advised by
271:Massachusetts Institute of Technology
109:Massachusetts Institute of Technology
7:
593:, asteroid named after Ostro in 1981
479:– the first asteroid for which the
844:People from Somerville, New Jersey
312:RADAR team, studying the moons of
25:
575:NASA Distinguished Service Medal
139:NASA Distinguished Service Medal
569:Division for Planetary Sciences
1:
817:"NASA's Asteroid Radar Group"
565:American Astronomical Society
208:potentially hazardous objects
874:People associated with radar
732:10.1016/0019-1035(88)90083-8
697:10.1016/0019-1035(79)90027-7
363:observed the contact binary
126:Marguerite, Brian, and Jules
646:"Steven J. Ostro 1946–2008"
628:"Asteroid radar highlights"
300:at MIT, Ostro served as an
900:
869:Cornell University faculty
515:, and Daniel J. Scheeres.
318:American Geophysical Union
854:Rutgers University alumni
750:Jet Propulsion Laboratory
200:Jet Propulsion Laboratory
181:
144:
39:
423:Bushveld Igneous Complex
324:Asteroid radar astronomy
225:Education and employment
393:Arecibo Planetary Radar
776:Cite journal requires
746:"Asteroid radar group"
561:Gerard P. Kuiper Prize
385:asteroid impact hazard
379:Asteroid impact hazard
337:
135:Gerard P. Kuiper Prize
67:Somerville, New Jersey
530:Work on other objects
331:
298:postdoctoral research
206:, including 130
849:American astronomers
656:on December 20, 2008
497:geosynchronous orbit
354:radar cross-sections
204:near-Earth asteroids
188:Steven Jeffrey Ostro
53:Steven Jeffrey Ostro
724:1988Icar...73...15O
689:1979Icar...40..355O
577:, posthumous (2010)
369:Arecibo Observatory
302:assistant professor
291:Arecibo Observatory
287:Galilean satellites
255:engineering physics
338:
259:Cornell University
247:Rutgers University
229:Ostro received an
105:Cornell University
101:Rutgers University
27:American scientist
275:Gordon Pettengill
267:planetary science
261:in 1974, and his
216:main belt objects
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146:Scientific career
78:December 15, 2008
16:(Redirected from
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501:Radar astrometry
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471:radiation forces
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171:Doctoral advisor
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194:. He worked at
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658:. Retrieved
654:the original
649:
648:. Obituary.
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632:jpl.nasa.gov
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599:Erdős Number
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509:Scott Hudson
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477:6489 Golevka
467:66391 Moshup
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361:Scott Hudson
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334:66391 Moshup
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235:liberal arts
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220:
218:with radar.
210:and 24
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80:(2008-12-15)
18:Steven Ostro
879:NASA people
839:2008 deaths
834:1946 births
409:nickel-iron
249:in 1969, a
87:Nationality
828:Categories
615:References
591:3169 Ostro
520:astrometry
499:in 2029.
389:Carl Sagan
289:using the
59:1946-03-09
563:from the
367:from the
269:from the
419:platinum
285:and the
251:Master's
212:binaries
123:Children
91:American
720:Bibcode
685:Bibcode
487:1950 DA
455:1998 KY
415:1986 DA
373:Arecibo
712:Icarus
677:Icarus
585:Eponym
571:(2003)
555:Awards
550:Honors
544:Deimos
540:Phobos
314:Saturn
237:and a
164:(1978)
162:
153:Thesis
131:Awards
118:Jeanne
115:Spouse
69:, U.S.
346:Ceres
257:from
245:from
782:help
662:2008
608:and
542:and
352:and
277:and
263:Ph.D
239:B.S.
231:A.B.
196:NASA
75:Died
49:Born
728:doi
693:doi
567:'s
306:JPL
265:in
253:in
241:in
233:in
198:'s
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