UCLA

The discovery and characterization of asteroids is necessary for understanding their demographics and their evolution within the Solar System. Diameter is an important asteroid property for assessing impact probabilities and uncovering clues about solar system origins. I assess how the accuracy of diameter estimates of asteroids based on infrared thermal modeling of imaging from the four-band Wide Field Infrared Survey Explorer (WISE) is dependent on the number of infrared bands used, as the NEO Surveyor mission will have only two infrared bands corresponding roughly to WISE bands W2 and W3. With a reparameterization of the near-Earth asteroid thermal model (NEATM), we found diameters modeled using observations from W2 and W3 bands to be systematically 10% smaller than their more accurate counterparts obtained with all four WISE bands. Obtaining high-quality orbits for faint main belt asteroids is foundational for many studies, particularly for projects related to solar system origins and asteroid families. I utilize the WISE mission dataset to detect and report new asteroid candidates using synthetic tracking, an algorithm which shifts and stacks pixels along a predicted on-sky motion template for an asteroid. We report astrometry to the Minor Planet Center for 8,223 discovery candidates and 13,575 known objects. We anticipate hundreds of discovery candidates will be linkable to asteroids discovered by the Vera Rubin Telescope, giving them excellent orbits arising from a > 15-year orbital arc. Assessing the lifetime of a typical near-Earth asteroid binary system as its orbit evolves is useful for understanding impact hazards. I use planetary radar delay-Doppler imaging taken of the 1999 KW4 near-Earth asteroid binary system with the Arecibo observatory and the Goldstone radar system between 2001 and 2019 to confirm the presence of libration for the secondary and measure the system’s orbital expansion rate. I find a best fitting outward orbital expansion rate for the semimajor axis of da/dt < 0.58 cm/yr, suggesting that the BYORP effect could play a role in evolving this system in combination with tidal evolution.