On Friday night, July 31, look skyward to see the second full moon of this month—a “Blue Moon.”
From Neil deGrasse Tyson, Director of the Hayden Planetarium:
“The average time between full moons is about 29.5 days. So any month but February can, in principle, harbor a Blue Moon. If you do the math, you will see that somebody gets a Blue Moon every 2.7 years, or so. Not particularly rare—no one thinks of Presidential elections as rare, yet they take place less often than Blue Moons. The Moon can actually look blue during rare (polluting) atmospheric conditions that involve volcanic eruptions and forest fires.”
Learn more about the summer sky from the Sky Reporter: bit.ly/1MWxCFX
