Why do full moons last the longest

Highest full moon of the yearThe longest night of the highest moon

On Tuesday (December 29th, 2020) the moon will be in the constellation Gemini, near the border with Taurus - exactly in the region where the sun is at the beginning of summer.

Tonight the full moon is in the constellation Gemini (Stellarium)

A team led by planetologist Shuai Li from the University of Hawaii has now discovered hematite, a mineral made from oxidized iron, on the moon. The researcher speaks casually of "rust" on the moon, which guarantees a great media response.

However, there is no fear that the moon will rust before our eyes. The mineral occurs only in negligibly small traces in the polar regions of the moon. The discovery was made with spectroscopic data from a NASA instrument on the Indian probe Chandrayaan-1, which flew to the moon in 2008.

Strongly exaggerated representation of the "rusty" hematite areas on the moon (Shuai Li, Univ. Of Hawaii / NASA)

It is unclear where the oxygen for the formation of the hematite comes from. The moon is bone dry and has very few water molecules in the surface material. It is possible that oxygen from the upper atmosphere of the earth reaches the moon whenever it moves through the earth's magnetic tail around the full moon.

That’s the case again tonight. Perhaps even now oxygen from the earth hits the polar regions of the moon, which causes the iron in the dust to oxidize. Tomorrow morning the moon will be slightly more "rusty" than it was tonight. If the moon rises or sets glowing red, this is not due to the hematite, but to the earth's atmosphere.