| Project Detail |
Understanding Earth’s precursor material
Earth-like exoplanets suggest efficient planet formation, necessitating an understanding of pathways to habitable worlds. Pebble accretion theory posits that millimetre-to-centimetre-sized pebbles are the primary building blocks for planets. Primitive chondrite meteorite pebbles offer a more accurate record of Earth’s precursor material. Chondrules, millimetre-sized and formed within 5 million years of the solar system’s formation, are ideal for studying the nature of matter that accreted to form rocky planets, including vital sources for life. In this context, the ERC-funded NEWROCK project aims to study chondrules, matrix and refractory components in chondrites to understand the precursor matter to terrestrial planets, probe how its composition varied in space and time, and evaluate the role of thermal processing and outward recycling in modifying inner disk matter.
The plethora of Earth-like exoplanets indicate that planet-formation is efficient, highlighting the need for unravelling the pathways to forming habitable worlds. The new planet-formation paradigm, i.e. pebble accretion, suggests that mm-to-cm sized pebbles are the main planetary building blocks as opposed to colliding proto-planetary bodies. Bulk samples of meteorites from asteroids, leftovers from the early Solar System, have been long used to infer the nature of Earth’s precursor material. However, pebble accretion predicts that pebble-like components of primitive chondrite meteorites provide a more accurate record of the precursor material to terrestrial planets, including the source of volatiles critical to life. The most abundant chondrite constituents are mm-sized chondrules hypothesized to be the pebbles driving planet formation. Chondrules formed within 5 Myr of the Solar System thus represent time-sequenced samples that can probe the nature of the matter, including its environment(s), that accreted to rocky planets. We will elucidate the origin and history of the matter precursor to terrestrial planets, by studying chondrules, matrix and refractory components in chondrites. This information is key for understanding the initial conditions allowing the formation of Earth-like planets. Combining isotope fingerprinting, age-dating and petrology, our data will be obtained using state-of-the-art techniques, including next generation collision cell and thermal ionization mass spectrometry as well as high-resolution imaging. We will identify the precursor matter to terrestrial planets and probe how its composition varied in space and time, identify the disk environment where the primordial population of planetesimals seeds formed and evaluate the role of thermal processing and outward recycling in modifying inner disk matter. With these goals, including high-risk high-gain ventures, we are in a strong position to make step change discoveries in cosmochemistry. |
