Eileen Ryan

Eileen Ryan
New Mexico Institute of Mining and Technology | NMT · Magdalena Ridge Observatory (MRO)

PhD

About

401
Publications
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Publications

Publications (401)
Article
Full-text available
On 2022 September 26, the Double Asteroid Redirection Test (DART) mission was the first successful demonstration of a kinetic impactor for planetary defense. The DART mission utilized a novel autonomous data processing pipeline architecture to quickly produce and analyze the quality of raw and calibrated images from the camera mounted on board the...
Article
Full-text available
The world’s first planetary defense test mission was carried out in late 2022 by NASA’s Double Asteroid Redirection Test (DART) mission. The main DART spacecraft, which was accompanied by the ASI-provided LICIACube cubesat, intentionally impacted Dimorphos, the smaller secondary of the near-Earth object binary system (65803) Didymos, on 2022 Septem...
Article
Full-text available
On 2022 September 26, the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, the satellite of binary near-Earth asteroid (65803) Didymos. This demonstrated the efficacy of a kinetic impactor for planetary defense by changing the orbital period of Dimorphos by 33 minutes. Measuring the period change relied heavily on a coordinate...
Article
Full-text available
The impact of the Double Asteroid Redirection Test spacecraft into Dimorphos, moon of the asteroid Didymos, changed Dimorphos’s orbit substantially, largely from the ejection of material. We present results from 12 Earth-based facilities involved in a world-wide campaign to monitor the brightness and morphology of the ejecta in the first 35 days af...
Technical Report
https://www.minorplanetcenter.net/mpec/K23/K23V01.html
Technical Report
Full-text available
https://www.minorplanetcenter.net/mpec/K23/K23UG2.html
Preprint
Full-text available
The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 minutes was expected if the incide...
Article
Full-text available
The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 minutes was expected if the incide...
Article
Understanding and predicting the evolving spin states of defunct geosynchronous (GEO) satellites and rocket bodies is important for space situational awareness, active debris removal, satellite servicing, and anomaly resolution. There is clear evidence that many defunct GEO satellite spin states are predominantly driven by the Yarkovsky-O’Keefe-Rad...
Preprint
On 15 February 2013, the asteroid 367943 Duende (2012 DA14) experienced a near-Earth encounter at an altitude of 27,700 km or 4.2 Earth radii. We present here the results of an extensive, multi-observatory campaign designed to probe for spectral and/or rotational changes to Duende due to gravitational interactions with the Earth during the flyby. O...
Article
Many defunct satellites in geosynchronous earth orbit (GEO) spin rapidly or have highly evolving spin states, with some transitioning between uniform and non-principal axis rotation (tumbling). It is hypothesized that the observed evolution of some defunct GEO satellites is caused by the Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect and inter...
Article
On 15 February 2013, the asteroid 367943 Duende (2012 DA14) experienced a near-Earth encounter at an altitude of 27,700 km or 4.2 Earth radii. We present here the results of an extensive, multi-observatory campaign designed to probe for spectral and/or rotational changes to Duende due to gravitational interactions with the Earth during the flyby. O...
Article
Impacts due to near-Earth objects (NEOs) are responsible for causing some of the great mass extinctions on Earth. While nearly all NEOs of diameter > 1 km, capable of causing a global climatic disaster, have been discovered and have negligible chance of impacting in the near future, we are far from completion in our effort to detect and characteriz...
Article
The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is a proposed explanation for the observed rotation behavior of inactive satellites in Earth orbit. This paper further explores the YORP effect for highly asymmetric inactive satellites. Satellite models are developed to represent the GOES 8 and GOES 10 satellites, both of which are currently...
Preprint
Small near-Earth asteroids (>20 meters) are interesting because they are progenitors for meteorites in our terrestrial collection. Crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors is the physical characteristics of these small near-Earth asteroids (NEAs). In the past, characterization of small...
Article
Small near-Earth asteroids (NEAs) (<20 m) are interesting, because they are progenitors for meteorites in our terrestrial collection. The physical characteristics of these small NEAs are crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors. In the past, the characterization of small NEAs has been a...
Conference Paper
Full-text available
Physical characterization of dim space objects in cis-lunar space can be a challenging task. Of particular interest to both natural and artificial space object behavior scientists are the properties beyond orbital parameters that can uniquely identify them. These properties include rotational state, size, shape, density and composition. A wide rang...
Article
Full-text available
Laboratory impact experiments on meter-scale targets were conducted to explore collisional outcomes pertinent to the problem of hazardous asteroid mitigation. In particular, the primary aim of the experiments was to improve our understanding of how the energy needed to fragment and disrupt an asteroid scales with size, such that mitigation strategi...
Article
Asteroid events such as the air blast above Chelyabinsk, Russia, in the spring of 2013 have highlighted the importance of understanding Earth's local asteroid population and the potential threat they pose. While much observational data exists for larger asteroids (those greater than 50 meters in diameter), comparatively little is known of the very...
Article
Full-text available
Asteroid surveys are the backbone of asteroid science, and with this in mind we begin with a broad review of the impact of asteroid surveys on our field. We then provide a brief history of asteroid discoveries so as to place contemporary and future surveys in perspective. Surveys in the United States have discovered the vast majority of the asteroi...
Article
CBET 3712 available at Central Bureau for Astronomical Telegrams.
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CBET 3534 available at Central Bureau for Astronomical Telegrams.
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Available from the Minor Planet Center.
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We describe the Pan-STARRS Moving Object Processing System (MOPS), a modern software package that produces automatic asteroid discoveries and identifications from catalogs of transient detections from next-generation astronomical survey telescopes. MOPS achieves > 99.5% efficiency in producing orbits from a synthetic but realistic population of ast...
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CBET 3290 available at Central Bureau for Astronomical Telegrams.
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Available from the Minor Planet Center.
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CBET 3238 available at Central Bureau for Astronomical Telegrams.
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Full-text available
NASA’s LCROSS (Lunar Crater Observation and Sensing Satellite) mission was designed to explore the nature of previously detected enhanced levels of hydrogen near the lunar poles. The LCROSS mission impacted the spent upper stage of the launch vehicle into a permanently shadowed region of the lunar surface to create an ejecta plume. The resultant im...
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CBET 3046 available at Central Bureau for Astronomical Telegrams.
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CBET 3048 available at Central Bureau for Astronomical Telegrams.
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CBET 3069 available at Central Bureau for Astronomical Telegrams.
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Available from the Minor Planet Center.
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Available from the Minor Planet Center.
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