It was created by the channel yeti dynamics back in 2013, but has been doing the rounds again after being posted on Reddit. It shows what would happen if, rather than being at its current distance of 380,000 kilometers (238,000 miles) on average, it was actually just 420 kilometers (260 miles) away from us.
“At this distance, the Moon would rise in the west and set in the east,” the video description notes. “Normally the Moon orbits much slower than the earth rotates so it rises in the east and sets in the west, however at 420km it orbits much faster, faster than the earth rotates underneath, therefore it will rise in the west and set in the east.”
The ISS is a paltry 109 meters (356 feet) across, so at its distance we see it as just a speck in the sky. The Moon, on the other hand, is a rather more cumbersome 3,474 kilometers (2,159 miles) across. At its closer position, it would obviously completely dominate the sky.
Astronomer Phil Plait, writing for Slate in 2013, noted that the Moon would fill more than half the sky. It would also appear to rotate, although it would actually still be tidally locked to our planet like it currently is. And some Earthlight would reflect onto the Moon, except for where the Moon blocks the Sun.
“The motion in the video is sped up; at that distance the Moon would orbit the Earth in about 90 minutes or so,” he writes. “It would cross the sky in very roughly five minutes.”
However, he also noted that Nick – the video’s creator – said he accidentally rendered the Moon upside down.
Of course, in reality, if the Moon was actually this close it would break apart due to gravitational forces, and it would probably have a pretty disastrous effect on Earth. Still, it’s fun to imagine what might happen.
Yeti dynamics has made some other interesting videos too, including what if the Moon was replaced by other planets and helping out on a vsauce video about the Moon being a disco ball, so check those out if this has piqued your interest.
Via IFLScience .