A Family of Asteroids Created from the Large Asteroid (6) Hebe

University Of North Dakota Main Campus, Grand Forks ND

Investigators

Abstract

When an asteroid is hit by another large solar system object, it can break apart and become many asteroids all of which have similar orbits. These smaller asteroids that were formed during the break-ups are the rocks that fall to Earth: smaller pieces of the asteroids are meteorites, and larger pieces become those asteroids that could threaten Earth with a big impact. Those asteroids that all come from one original asteroid are called a "family." Astronomers use telescopes and instruments to look at the types of rocks on the asteroids in the families we find today to see if they have similar compositions. Comparing the orbits and the compositions in an asteroid family gives us information on how long ago the break-up of the asteroid parent happened. The Principal Investigator will observe about 35 asteroids near the large asteroid (6) Hebe to learn their compositions and, from that, their possible family beginning. This research serves the national interest by promoting the progress of planetary astronomy, as well as providing information to secure national defense and welfare when Earth is threatened by the possible impact of a large asteroid. The project will include students, aiming especially to identify female and disabled students as possible, to teach them how a scientific study is conducted. Asteroid families are a collection of objects formed during the collisional breakup of a parent asteroid or as the ejecta from a large impact onto a parent body. These events are major sources of the meteoroids that fall to Earth as meteorites, and of the Earth-approaching objects which constitute a potential impact hazard. Asteroid families eventually diffuse orbitally to become the background asteroid population; as such, the time scale of diffusion constrains the ages of families and the collisional rate in the asteroid belt. The H-chondrite meteorites exhibit a range of metamorphism suggesting deep excavation from their parent body, and spectral properties similar to asteroid (6) Hebe. This research seeks a spectroscopic investigation of 35 asteroids in the dynamical region near Hebe to test for the presence of a small dynamical family of H-chondrite composition. Detection or non-detection of such a family would place constraints on the formation of impact-generated families by providing data to the modeling community to test orbital diffusion models in regions proximate to resonances, as well as provide an explanation for the diverse thermal histories of the H-chondrites. The proposed research effort would also provide a strong test of spectroscopic and dynamical predictions regarding asteroid family identification. The PI will also focus on recruiting and teaching students, emphasizing female and disabled individuals as possible, the specific scientific investigation and writing techniques that would prepare them to become strong, diverse scientists and educators in the globally competitive STEM workforce.