Halloween will offer a special treat for stargazers this year. For the first time since 1944, a full moon will be visible on October 31 in Pittsburgh and across all U.S. time zones, according to the Farmer’s Almanac. It will also be a Blue Moon, which happens when there are two full moons in one month. The first was on October 1.
Dr. Sandhya Rao with the University of Pittsburgh’s Department of Physics and Astronomy said it doesn’t happen very often. “The time between two full moons is about 29 and a half days. So, you can imagine that within a calendar month, it is rare to get two full moons in 30 or 31 days,” Rao said.
The full moon will rise at sunset on Halloween, at approximately 6:20 in the evening. “If you have a clear view of the horizon you can watch the full moon rise," Rao said. "If it’s clear, a rising full moon is a spectacular site."
While cloudy weather is common in Pittsburgh, this year meteorologists say Mother Nature will cooperate. “There will be no obstructions to viewing with mainly clear skies on Halloween night,” said Lee Hendricks with the National Weather Service in Pittsburgh.
The moon has also taken center stage at NASA this week with the space agency announcing that water has been found on the sunlit lunar surface. Rao said it’s a significant breakthrough because experts previously thought only the dark, icy side of the moon contained water.
“People always thought if water existed on the moon, you wouldn’t see it on the sunlit side because sunlight breaks apart any water molecules and it would evaporate because the moon does not have an atmosphere,” Rao noted.
The discovery comes from observations of the lunar surface by an infrared telescope on SOFIA, a modified Boeing 747 jetliner that flies high in the earth’s atmosphere. SOFIA was able to pick up the specific wavelength unique to water molecules, and discovered a surprising concentration in the moon’s sunny Clavius Crater.
Rao said the research will benefit future missions to the moon. According to experts, making use of water that’s already present, rather than transporting it from Earth, could make space travel cheaper and easier.
Rao also said the NASA announcement coming the same week as a rare full moon is exciting both scientifically and culturally. “I think the juxtaposition of these two events is a bright spot in our world today,” Rao said.
