How we know stuff about asteroids

We recently got more detail on the 2103 new asteroids discovered by the Rubin Observatory in its first look data back in summer 2025. We can tell a lot about an asteroid from how its brightness changes with time: its size, rotation rate, density, and what it’s made of! #astronomy #astrophysics #science #asteroid 👩🏽‍💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford (Christ Church). I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars. http://drbecky.uk.com