On the night of May 25-27, observers in Oceania, Hawaii, eastern Asia and Antarctica will see a lunar eclipse that coincides with the moon’s closest approach to Earth — making it a “supermoon” eclipse that will turn the moon reddish — also known as a “blood moon.” (The dates of this eclipse span two days because the area it will be visible spans the international date line).
Lunar eclipses occur when the moon is on the opposite side of the Earth as the sun. Usually we see a full moon when this happens, but every so often the moon enters the Earth’s shadow, resulting in an eclipse. This doesn’t happen every full moon because the plane of the moon’s orbit is tilted about 5 degrees from the plane of the Earth’s orbit, and the moon “misses” the shadow of the Earth.
Unlike a solar eclipse, which is only visible along a narrow track, lunar eclipses are visible from the entire night side of the Earth; this entire eclipse takes about five hours from start to finish. The timing depends a lot on what time zone you are in, relative to what is called Universal Coordinated Time (effectively the hour in Greenwich, England). In Asia, the eclipse occurs near moonrise in the evening. On the west coast of the Americas, the eclipse happens in the early morning hours, near moonset. The best viewing will be in between those two extremes: Australia, New Zealand, Hawaii, the islands of the South Pacific and southwestern Alaska.