Near-Earth Object Reconnaissance and Source Region Analysis

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

AST 0506716 Binzel With this award, Dr. Richard Binzel and colleagues will achieve an increased understanding of the basic characteristics and the origins for the population of small bodies residing in orbits intersecting (or closely approaching) the orbit of the Earth. These near-Earth objects (NEOs) are important scientifically as they are the most immediate and representative source bodies for the delivery of meteorites to the Earth. Currently NEOs have mostly unknown origins from locations within the main asteroid belt and from extinct comets. A multi-year commitment of observing time (~2 nights per month over an initial period of two years) has been made by the NASA Infrared Telescope Facility (IRTF) at Mauna Kea, Hawaii for the purpose of enabling routine reconnaissance of newly discovered NEOs. NSF funding of this project will support the acquisition of these reconnaissance observations resulting in new spectral data for 80 to 100 NEOs per year, where all new data obtained will be reduced and publicly released in near-real time. In short order, this new reconnaissance program will eclipse the current number (~140) of NEOs having near-infrared spectral measurements. The specific science goals for these reconnaissance observations are: (1) To relate, as closely as possible, NEO spectral characteristics with major meteorite classes. (2) To quantitatively determine the relative consistency (or lack thereof) between the NEO population classes measured in space and the meteorite population classes determined by fall statistics on Earth. (3) To identify, as well as possible, specific main-belt source regions for specific classes of NEOs, and in turn, illuminate solar system origin links for specific meteorite types. (4) To characterize the properties of NEOs in comet-like orbits for the objective of illuminating asteroid-comet connections, thereby constraining the comet source fraction for NEOs. (5) To measure the spectral characteristics of NEOs residing in orbits reachable with propulsion requirements < 7 km/sec, so that mission planning can be driven by scientific criteria (basic knowledge of the target properties) rather than by simple dynamical requirements. (6) Separately evaluate the compositional properties of the potentially hazardous asteroid (PHA) subgroup, to illuminate any difference in the relative hazard posed by these most closely approaching objects compared with the broader NEO population. Dr. Binzel and his team bring extensive spectroscopic experience to this project with more than 10 refereed publications and ~140 NEO observations obtained within the first two years of the prior three year funding period, and a substantially longer track record in asteroid research. The long-term interests of society dictate that we achieve an understanding of the NEO population for assessing their impact hazard and potential for natural resource utilization in space. Linking astronomical measurements of NEOs to laboratory measurements of meteorites provides a broad connection across different scientific disciplines. Identifying source regions for NEOs linked to meteorite classes anchors a wealth of laboratory meteorite data on solar system formation conditions to distinct locations as important boundary conditions for forming planets in our own solar system and beyond. The proximity of NEOs make them the most easily accessible destinations for spacecraft exploration, making their reconnaissance critical for both American and international space exploration planning, including possible future human missions and future utilization of NEOs as space resources. Finally, the IRTF observations are to be conducted by remote observing from the MIT campus, allowing the integration of research and education for a substantial number of students who could not otherwise travel to the telescope. ***