The origin of the great oceans on Earth is the subject of contentious debate among planetary scientists. To trace the source of our water, Arizona State cosmochemist Maitrayee Bose studied tiny particles from the asteroid Itokawa for clues. Her findings have dramatic implications for water stores not just on Earth but also other planets in our solar system.

When a gunman opened fire and killed two students at the University of North Carolina at Charlotte on the last day of class on Tuesday, it fit a familiar pattern of shootings on U.S. college campuses. An analysis of campus shootings by researchers Jillian Peterson and James Densley shows that the vast majority take place during the end of the academic year – just one of many patterns they say authorities can use to develop prevention strategies.

President Trump and Democratic leaders agreed to spend $2 trillion to mend America’s crumbling road, waste and water infrastructure. But with so much to fix, where to start? Colorado State economist Steven Pressman identifies three areas he thinks should be top priorities – not just because they urgently need investment but because they could help fight economic inequality as well.