Dave Weinrich, Minnesota State University Moorhead's planetarium coordinator for the past 25 years, has been elected to a six-year term as president-elect of the International Planetarium Society.

Blue moons happen because the length of time between full moons is 29½ days, Weinrich says. If there's a full moon early enough in the month, there can be a second one at the end of the month.

This year's guest speakers are Craig Howe, who is the director of the South Dakota-based Center for American Indian Research and Native Studies, and Dave Weinrich, the former president of the ...