IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2022A076 PROGRAM_TITLE Mapping Water in the Outer Asteroid Belt PROGRAM_INV1 Sarah Sonnett PROGRAM_INV2 Driss Takir PROGRAM_INV3 Vishnu Reddy PROGRAM_INV4 Zachary Smith PROGRAM_INV5 Lucy Williamson 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 quadruple the number of Cybeles and Hildas with full water characterization and lead high-impact investigations, including: [1] constraining the heliocentric extent of hydrated material by characterizing the 3.0-micron water band, telling us whether or not 26-Al [its decay one of the primary solar system heating sources] accumulated more quickly in bodies closer to the Sun, as predicted by evolutionary models; [2] investigating Hildas or Cybeles as 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, which still preserve their hydration signatures; and [3] exploring size-hydration trends that may help drive thermal evolution within asteroids by comparing depth of the 3.0-micron band to asteroid size. The proposed observations will be nearly simultaneously paired with visible spectra [0.4-0.8 microns] to be collected at proprietary telescopes in order to fully profile the water content of the targets. We request observations of the 4 targets accessible during 2022A from our full sample of 32 targets to be observed through IRTF's 2024A semester. PROGRAM_ABSTRACT_END