Work led by Carnegie’s Peng Ni and Anat Shahar uncovers new details about our Solar System’s oldest planetary objects, which broke apart in long-ago collisions to form iron-rich meteorites.  Their findings reveal that the distinct chemical signatures of these meteorites can be explained by the process of core crystallization in their parent bodies, deepening our understanding of the geochemistry occurring in the Solar System’s youth. They are published by Nature Geoscience.

A team of astronomers including Carnegie’s Ting Li and Alexander Ji discovered a stellar stream composed of the remnants of an ancient globular cluster that was torn apart by the Milky Way’s gravity 2 billion years ago, when Earth’s most-complex lifeforms were single-celled organisms. This surprising finding, published in Nature, upends conventional wisdom about how these celestial objects form.

Filling in the most-significant gaps in our understanding of the universe’s history, the Sloan Digital Sky Survey (SDSS) released Sunday a comprehensive analysis of the largest three-dimensional map of the cosmos ever created. “SDSS has transformed the way we do astronomy, with each phase pushing the boundary of what is considered possible,” said Carnegie astronomer and SDSS-V Director Kollmeier. “The eBOSS cosmology results are no exception, filling in an important gap in our measurements of cosmic evolution and demonstrating the collaborative power of the SDSS consortium.”

The universe is full of billions of galaxies—but their distribution across space is far from uniform. Why do we see so much structure in the universe today and how did it all form and grow? A 10-year survey of tens of thousands of galaxies made using the Magellan Baade Telescope at Carnegie’s Las Campanas Observatory in Chile provided a new approach to answering this fundamental mystery.