Analysis of deep-sea terrestrial archives by ultra-sensitive accelerator mass spectrometry (AMS) reveals deposition of fresh nucleosynthesis products from the interstellar medium. Two radionuclides, 60Fe (t1/2= 2.6 My) and 244Pu (81 My), short-lived on Galactic time scale, are detected in slowly accumulating crusts and sediments of deep ocean by AMS experiments performed at ANU and VERA. Time-resolved global deposition of 60Fe, primarily produced in explosive nucleosynthesis, is observed over the last 10 My testifying of supernova activity in the vicinity of the Solar system. The 244Pu actinide can act as a probe of recent and close-by r-process nucleosynthesis which is its sole production mode in Nature. The abundance of 244Pu positively detected in the deep-sea archives is lower by a factor of approximately 100 than expected from supernovae production and is compatible with neutron-star merger r-process nucleosynthesis. This work was funded by the Austrian Science Fund (FWF), project number I428-N16 and within the ESF Eurogenesis programme; the Australian Research Council (ARC), project number DP14100136; the Japan Society for the Promotion of Science (JSPS) KAKENHI, grant number 26800161; Israel Sience Foundation, grant number 43/01.

†ANU – Australian National University

HUJ - Hebrew University of Jerusalem

SHIMZ - Institute of Technology, Shimizu Corporation, Tokyo, Japan

VERA - University of Vienna, Faculty of Physics—Isotope Research, VERA Laboratory