Hopes Fade for Resurrecting Puerto Rico's Famous Arecibo Telescope

Can geothermal energy supply all of the UK's heating?

NASA's Webb Uncovers Dense Cosmic Knot in The Early Universe

What's going on with Elon Musk, SpaceX's Starlink and Ukraine? Here's what we know. SpaceX asked the Pentagon for Starlink Ukraine funding help but soon retracted the request.