Why is this a supermoon, too?
The moon’s orbit is not a perfect circle around Earth but rather an ellipse, so sometimes it will be closer and farther from our planet. This month’s supermoon should make our natural satellite appear about seven percent larger and brighter than usual in the sky, though most people will have a hard time telling the difference.
When the moon is close to the horizon, it tends to appear extremely big, a well-known optical illusion that has so far defied complete explanation. Some people hear about supermoons, witness this effect, and believe they have seen something special. But the two are unrelated, Dr. Krupp said.
Supermoons lining up with lunar eclipses aren’t uncommon. The most recent super blood moon was on Jan. 21, 2019, and the next is May 16, 2022. The fact that headlines have focused on creating fun names such as the “super flower blood moon” for this month’s eclipse “is strictly a product of the internet age,” Dr. Krupp said. “We are paying attention to celestial events in far more detail than before.”
But in that sense, it is almost a return to an earlier era, when the sky had much more meaning to everyday people’s lives.
“I have no quarrel with the digital age bringing attention to things that would pass by without notice,” he added.
What science is happening during the eclipse?
Research during lunar eclipses has a long pedigree. Aristotle demonstrated that Earth was a sphere by pointing out that it always casts a round shadow on the moon, no matter where on the ground the eclipse was seen or where the moon was in the sky. Only a spherical object, he reasoned, could produce a circular shadow from every angle.
In the modern day, NASA has used instruments on the Lunar Reconnaissance Orbiter, a robotic spacecraft around the moon, to take temperature readings of the lunar surface as it passes into Earth’s shadow. By observing how quickly different rocks cool, scientists can infer their density, Dr. Guhathakurta said.