Look up next Sunday to see a truly special cosmic event: a supermoon total lunar eclipse.
Not only will the moon be at its closest point point to Earth in it orbit on Sept. 27, it will also pass completely into Earth’s shadow, turning the lunar body into a red-tinted “blood moon” for anyone who has clear, dark skies on the planet’s surface.
“All of South America and most of North and Central America will see the entire eclipse, while those west of roughly 120°W will see it in progress at moonrise,” NASA said in a statement. “You won’t need special equipment to see it. Just go outside and look up!”
This will mark the first time a total lunar eclipse during a supermoon has occurred since 1982, and it won’t happen again until 2033.
During a supermoon, the moon can actually look up to 14% larger in diameter; however, everyday skywatchers might not be able to tell the difference.
The moon shines red during total lunar eclipses because some sunlight passes through the Earth’s atmosphere and shines onto the lunar surface, casting it in a ghostly pallor.
The eclipse begins when the moon passes through Earth’s penumbra — the outer, lighter shadow cast by the planet. It will then move fully into the umbra, the dark shadow cast by the planet, at which point, the moon will be cast in a red light.
“The real action begins when the Moon starts to disappear as it enters the umbra at about 9:07 EDT,” NASA said in the statement. “An hour later, entirely within the umbra, the Moon is a ghostly copper color, and this lasts for over an hour before the Moon begins to emerge from the central shadow.”
Scientists can also collect a fair bit of data about the moon during a lunar eclipse that they wouldn’t be able to get otherwise.
For example, NASA’s Lunar Reconnaissance Orbiter (LRO) will be able to take measurements of the moon’s surface temperature.
“With that measurement, we can learn about about the characteristics, the properties of the moon, and particularly during an eclipse, we learn about the upper, upper most surface,” NASA LRO deputy project scientist Noah Petro, said in a NASA video interview.
By learning more about how the temperature of the surface of the moon changes, scientists can actually have new insights about the structure of the surface of the moon, Petro added.