  Chondrites are rocky fragments of asteroids that formed at different times
and heliocentric distances in the early solar system. Most chondrite groups
contain water-bearing minerals, attesting that both water-ice and dust were
accreted on their parent asteroids. Nonetheless, the hydrogen isotopic
composition (D/H) of water in the different chondrite groups remains poorly
constrained, due to the intimate mixture of hydrated minerals and organic
compounds, the other main H-bearing phase in chondrites. Building on our recent
works using in situ secondary ion mass spectrometry analyses, we determined the
H isotopic composition of water in a large set of chondritic samples (CI, CM,
CO, CR, and C-ungrouped carbonaceous chondrites) and report that water in each
group shows a distinct and unique D/H signature. Based on a comparison with
literature data on bulk chondrites and their water and organics, our data do
not support a preponderant role of parent-body processes in controlling the D/H
variations among chondrites. Instead, we propose that the water and organic D/H
signatures were mostly shaped by interactions between the protoplanetary disk
and the molecular cloud that episodically fed the disk over several million
years. Because the preservation of D-rich interstellar water and/or organics in
chondritic materials is only possible below their respective sublimation
temperatures (160 and 350-450 K), the H isotopic signatures of chondritic
materials depend on both the timing and location at which their parent body
formed.
