A Comet That Last Passed When Humans Painted Cave Walls Is Back This Week

Plus: Moon patches that surprised scientists, mammal-eating orcas far from home, and the baldness treatment that may have missed the point

Dear friends,

This Monday morning brought a good mix. A prehistoric comet is visible before sunrise for the first time in 170,000 years. A stolen Van Gogh turned up in an Ikea bag and is now restored and back on the wall. Alaskan orcas showed up in Seattle with no explanation. Ants are cleaning each other’s teeth in the Arizona desert. And the moon, it t…