Bridge Between Spiral Galaxies Seen From Hubble

Bridge Between Spiral Galaxies Seen From Hubble

Why is there a bridge between these two spiral galaxies? Made of gas and stars, the bridge provides strong evidence that these two immense star systems have passed close to each other and experienced violent tides induced by mutual gravity. Known together as Arp 240...
Guide to Radiation Doses

Guide to Radiation Doses

fascinating chart of the “ionizing radiation dose a person can absorb from various sources;” from using a cell phone to CT Scans to being at Chernobyl and Fukushima when disaster struck.