Is the Massalia family of asteroids the source of the L-chondrite meteorites?

University Of North Dakota Main Campus, Grand Forks ND

Investigators

Abstract

Asteroids have long been believed to be the primary source of meteorites. In many cases, ?parent? bodies of meteorites have been determined by comparing the way those meteorites and specific asteroids reflect sunlight. However, the parent body of the most common type of meteorites seen to fall, known as ordinary chondrites, has yet to be firmly identified. The team's hypothesis is that a group known as L-chondrites come from the (20) Massalia family of asteroids (An asteroid family is a group of asteroids with orbits more similar than would be expected by chance). The team will use telescopes to break down the light reflected by the Massalia asteroids for comparison with L-chondrites studied in the laboratory. Both undergraduate and graduate students will be included in the research. This project is jointly funded by NSF AST and the Established Program to Stimulate Competitive Research (EPSCoR). Main belt asteroids are the sole surviving in situ remnants from the formation epoch of the inner Solar System. With few exceptions, meteorites are samples of main belt asteroids. Meteorites thus provide a window into the condition and processes in the late stages of the solar nebula and the earliest evolution of the inner Solar System. Studying meteorites tells us about the geochemistry and petrology of the Solar System, and about its age (from radiometric dating), but nothing about where these processes occurred. If the L-chondrites can be linked to a specific asteroid family, the late nebular and early solar system location of the conditions and processes recorded by the L-chondrites can be constrained. Moreover, the age of that family can be established by the shock ages of the L-chondrites. A firm constraint on the age of a family would allow a more rigorous testing and refining of dynamical models of orbital diffusion in the asteroid belt. Such models are important for: A) constraining the sources of Earth-approaching meteoroids and asteroids, B) for modeling the dynamical evolution of the asteroid population, and C) for estimating the ages of other asteroid families and hence the frequency of large collisions in the belt. The overall goal of the present study is to test the (20) Massalia asteroid family as a potential source of the L-chondrites. This work will be done by comparing spectra of Massalia asteroids for comparison with laboratory spectra of L-chondritic meteorites. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.