# # Program information file # PROGRAM_ID 2023A046 PROGRAM_TITLE Mapping Water in the Outer Asteroid Belt PROGRAM_INV1 Sarah Sonnett PROGRAM_INV2 Vishnu Reddy PROGRAM_INV3 Driss Takir PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT main-belt / Trojan asteroids PROGRAM_ABSTRACT_BEG Water played a fundamental role in the emergence of life. Understanding its distribution and behavior in the solar system helps constrain the dynamical and chemical evolution of the solar system and the possible source regions for Earth's water. However, the extent and form of water on asteroids is not well known largely because observational data at key heliocentric distances [~3.2-4.2 AU, dominated by Cybele and Hilda asteroids] are meager. Our study will remedy these problems by conducting the largest comprehensive search for water at these key transition distance between once-liquid and perpetually frozen water ice. Though many Hilda and Cybele spectra have been published, none adequately explore the water bands. Ultimately, we will nearly triple the number of Cybeles and Hildas with full water characterization and lead high-impact investigations, including: [1] constraining the heliocentric extent of hydrated material via its 3-micron water band, exploring the historical ammonia condensation line and how quickly 26-Al [a primary solar system heating source] accumulated in different regions of the Main belt; [2] investigating Hildas and Cybeles as brethren to the parent bodie[s] of CM/CI meteorites [possible remnants of the bodie[s] that delivered the Earth's oceans] by comparing 0.9- and 1.1-micron band shapes and depths between the targets and CM/CI samples; and [3] exploring size-hydration trends that may help drive thermal evolution within asteroids by comparing depth of the 3-micron band to asteroid size. We request observations of the 4 targets accessible during 2023A from our full sample of 27 targets to be observed through IRTF's 2024A semester. PROGRAM_ABSTRACT_END