A5034179199- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Geological and Geochemical Analysis
- Stellar, planetary, and galactic studies
- Geology and Paleoclimatology Research
- High-pressure geophysics and materials
- Astrophysics and Star Formation Studies
- Paleontology and Stratigraphy of Fossils
- Space Exploration and Technology
- Geochemistry and Elemental Analysis
- Radioactive element chemistry and processing
- Geochemistry and Geologic Mapping
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- earthquake and tectonic studies
- Methane Hydrates and Related Phenomena
- Spacecraft and Cryogenic Technologies
- Geomagnetism and Paleomagnetism Studies
- Mineralogy and Gemology Studies
- Solar and Space Plasma Dynamics
- Marine and environmental studies
- Metallurgical Processes and Thermodynamics
- Hydrocarbon exploration and reservoir analysis
- Radioactive contamination and transfer
University of Copenhagen
2016-2025
Institut de physique du globe de Paris
2017-2025
Université Paris Cité
2017-2025
University of Hawaiʻi at Mānoa
2009-2025
IT University of Copenhagen
2024
Centre National de la Recherche Scientifique
2018-2023
Natural History Museum Aarhus
2012-2021
Styrelsen for Arbejdsmarked og Rekruttering
2019-2021
Sorbonne Paris Cité
2017-2020
Natural History Museum of Denmark
2014-2020
Transient heating events that formed calcium-aluminum-rich inclusions (CAIs) and chondrules are fundamental processes in the evolution of solar protoplanetary disk, but their chronology is not understood. Using U-corrected Pb-Pb dating, we determined absolute ages individual CAIs from primitive meteorites. define a brief formation interval corresponding to an age 4567.30 ± 0.16 million years (My), whereas chondrule range 4567.32 0.42 4564.71 0.30 My. These data refute long-held view gap...
Stable-isotope variations exist among inner solar system solids, planets, and asteroids, but their importance is not understood. We report correlated, mass-independent of titanium-46 titanium-50 in bulk analyses these materials. Because have different nucleosynthetic origins, this correlation suggests that the presolar dust inherited from protosolar molecular cloud was well mixed when oldest solids formed, requires a subsequent process imparting isotopic variability at planetary scale. infer...
Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but mechanism is not understood. We show main growth asteroids can result gas drag-assisted accretion chondrules. largest planetesimals a population with characteristic radius 100 km undergo runaway within ~3 My, forming planetary embryos up to Mars's size along...
With a half-life of 0.73 Myr, the 26Al-to-26Mg decay system is most widely used short-lived chronometer for understanding formation and earliest evolution solar protoplanetary disk. However, validity 26Al–26Mg ages meteorites their components relies on critical assumption that canonical 26Al/27Al ratio ∼5 × 10−5 recorded by oldest dated solids, calcium–aluminium-rich inclusions (CAIs), represents initial abundance 26Al as whole. Here, we report high-precision Mg-isotope measurements inner...
Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples the asteroid (162173) Ryugu were retrieved by Hayabusa2 spacecraft. We measured mineralogy and bulk chemical isotopic compositions samples. The samples mainly composed materials similar those carbonaceous chondrite meteorites, particularly CI (Ivuna-type) group. consist predominantly minerals formed in aqueous fluid on a parent planetesimal. primary altered fluids at temperature 37° ± 10°C, about...
Age dating of meteorite inclusions suggests rapid formation the building blocks terrestrial planets within 1 My Sun.
Significance Comets are pristine, volatile-rich objects formed beyond the orbits of gas giants and, thus, thought to preserve a record primordial molecular cloud material parental our Solar System. We use magnesium and chromium isotopes show that class pristine chondrites, metal-rich carbonaceous has signature distinct from most inner System planets asteroids. This is consistent with predicted for unprocessed material, suggesting that—similar comets—metal-rich chondrites samples asteroids...
A new theory for formation of Earth by accretion small pebbles explains how our planet acquired its water and carbon.
Constraining the timescales for assembly and differentiation of planetary bodies in our young solar system is essential a complete understanding planet-forming processes. This best achieved through study daughter products extinct radionuclides with short half-lives, as they provide unsurpassed time resolution compared to long-lived chronometers. Here we report high-precision Mg isotope measurements bulk samples basalt, gabbro, pyroxenite meteorites obtained by multiple-collector inductively...
Determining the origins of our solar system and, by proxy, other planetary systems, depends on knowing accurately and precisely timing tempo transformation disk gas dust to solids that formed planets. Relative ages based short-lived nuclide 26Al indicate high-temperature calcium-aluminum inclusions (CAIs) before lower temperature chondrules but these are heavily dependant a model homogeneous distribution within protoplanetary disk. The competing X-wind argues for heterogeneous due its...
We report novel methods for the chemical purification of Mg from silicate rocks by ion-exchange chromatography, and high-precision analysis Mg-isotopes high-resolution multiple collector inductively coupled plasma source mass spectrometry (HR-MC-ICPMS). Using these methods, we have measured relative absolute Mg-isotope composition a number terrestrial extraterrestrial materials, including international reference rock standards as well pure standards, olivine crystals separated mantle-derived...
Of the long-lived chronometric systems, only dual decay of 238U and 235U to 206Pb 207Pb, respectively, have appropriate half-lives resolve ages meteorites their components formed in first 5 Myr Solar System. This paper reviews theory methods behind this chronometer, offers criteria critically evaluate Pb–Pb presents a summary current state immediate future chronometry early We recognize that there is some debate over age System, but conclude an 4567.30 ± 0.16 Ma based on four CAIs dated...
Abstract The CB chondrites are metal‐rich meteorites with characteristics that sharply distinguish them from other chondrite groups. Their unusual chemical and petrologic features a young formation age of bulk chondrules dated the Gujba interpreted to reflect single‐stage impact origin. Here, we report high‐precision internal isochrons for four individual probe history evaluate concordancy relevant short‐lived radionuclide chronometers. All define brief interval weighted mean 4562.49 ± 0.21...
Significance We have discovered 2 major oceanic anoxic events (OAEs) in the early Cambrian at time when animals markedly diversified. present a multiproxy constraint on global biogeochemical cycles to show that these events, contrast most younger OAEs, could been driven by declining atmospheric O levels, plausibly set off appearance of bioturbating animals. Pulses animal appearances may occurred different times continents, but last pulse after OAEs and we predict higher marine productivity...
The iron isotope composition of Earth’s mantle requires planetary growth within 5 Ma solar system formation.
Little is known about the origin of spectral diversity asteroids and what it says conditions in protoplanetary disk. Here, we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable Ivuna-type (CI) chondrites, which are distinct all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate CI chondrites formed a reservoir was different source regions asteroids. Growth migration giant planets destabilized nearby planetesimals ejected some...