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Asteroid pairs are genetically related asteroids that recently separated ($<$few million years), but still reside on similar heliocentric orbits. A few hundred of these systems have been identified, primarily in the asteroid main-belt. Here we studied a newly discovered pair of near-Earth objects (NEOs): 2019 PR2 and 2019 QR6. Based on broad-band photometry, we found these asteroids to be spectrally similar to D-types, a type rare amongst NEOs. We recovered astrometric observations for both asteroids from the Catalina Sky Survey from 2005, which significantly improved their fitted orbits. With these refinements we ran backwards orbital integrations to study formation and evolutionary history. We found that neither a pure gravitational model nor a model with the Yarkovsky effect could explain their current orbits. We thus implemented two models of comet-like non-gravitational forces based on water or CO sublimation. The first model assumed quasi-continuous, comet-like activity after separation, which suggested a formation time of the asteroid pair $300^{+120}_{-70}$ years ago. The second model assumed short-term activity for up to one heliocentric orbit ($\sim$13.9 years) after separation, which suggested that the pair formed 272$\pm$7 years ago. Image stacks showed no activity for 2019~PR2 during its last perihelion passage. These results strongly argue for a common origin that makes these objects the youngest asteroid pair known to date. Questions remain regarding whether these objects derived from a parent comet or asteroid, and how activity may have evolved since their separation.

We report on low-spectral resolution observations of comet 9P/Tempel 1 from 1983, 1989, 1994 and 2005 using the 2.7m Harlan J. Smith telescope of McDonald Observatory. This comet was the target of NASA's Deep Impact mission and our observations allowed us to characterize the comet prior to the impact. We found that the comet showed a decrease in gas production from 1983 to 2005, with the the decrease being different factors for different species. OH decreased by a factor 2.7, NH by 1.7, CN by 1.6, C$_{3}$ by 1.8, CH by 1.4 and C$_{2}$ by 1.3. Despite the decrease in overall gas production and these slightly different decrease factors, we find that the gas production rates of OH, NH, C$_{3}$, CH and C$_{2}$ ratioed to that of CN were constant over all of the apparitions. We saw no change in the production rate ratios after the impact. We found that the peak gas production occurred about two months prior to perihelion. Comet Tempel 1 is a "normal" comet., Comment: Accepted for publication in Icarus. 21 total manuscript pages including 8 tables and 4 figures

In cooperation with the NASA Crustal Dynamics Project initiative placing workstation computers at each of its laser ranging stations to handle data filtering and normalpointing, MLRS personnel have developed a new generation of software to provide the same services for the lunar laser ranging data type. The Unix operating system and X windows/Motif provides an environment for both batch and interactive filtering and normalpointing as well as prediction calculations. The goal is to provide a transportable and maintainable data reduction environment. This software and some sample displays are presented. that the lunar (or satellite) datacould be processed on one computer while data was taken on the other. The reduction of the data was totally interactive and in no way automated. In addition, lunar predictions were produced on-site, another first in the effort to down-size historically mainframe-based applications. Extraction of earth rotation parameters was at one time attempted on site in near-realtime. In 1988, the Crustal Dynamics Project SLR Computer Panel mandated the installation of Hewlett-Packard 9000/360 Unix workstations at each NASA-operated laser ranging station to relieve the aging controller computers of much of their data and communications handling responsibility and to provide on-site data filtering and normal pointing for a growing list of artificial satellite targets. This was seen by MLRS staff as an opportunity to provide a better lunar data processing environment as well.