Episodes

The winter solstice is the shortest day, and the longest night, of the year. It’s been celebrated by cultures around the world since our earliest history. The winter solstice comes on or around December 21st—and 6 months later in the Southern Hemisphere. Leading up to it, the days appear to be dying. The dawn comes later, the sunset earlier. Nights get longer and colder. In far northern and southern latitudes, this is very keenly felt. Then on the solstice, things turn around. The day after is a...

Volcanic eruptions can affect global warming—or cooling. And one of the ways we measure their impact is by looking at a lunar eclipse. To understand this strange connection, we need to know a bit about Earth’s atmosphere. The lowest part, the troposphere, extends from the surface up 4 to 12 miles. It’s where Earth’s weather happens. The stratosphere, above that, is dry and less active. Dust and ash particles carried into the troposphere by volcanoes, fires, or other sources will quickly fall or ...