This week, a partial lunar eclipse will occur, overnight from Thursday, November 18 through the early morning hours of Friday, November 19. It will be very long compared to a typical length for an eclipse; the duration is expected to be 3 hours, 28 minutes, and 23 seconds. The last eclipse that was this long happened in 1440, and another like it won't happen until 2669. Even though it's a partial eclipse, it will be near-total, according to NASA.
During a lunar eclipse, the Moon is opposite the Sun, with the Earth in between, and our planet's shadow covers the moon. In a total lunar eclipse, the moon is totally blocked out. On the night of November 18th, the Moon will pass through the southern portion of the Earth's shadow, and 97 percent of the Moon will be obscured as the Moon and Sun sit nearly opposite one another. The bit of the Moon that is visible will take on a reddish-brown tint.
If there are clear skies in their area, many people will be able to view the eclipse, including North America, large parts of South America, eastern Australia, and northeastern Asia.
The partial eclipse starts on the East Coast of the United States just after 2 a.m. (7:20 a.m. UTC) and reaches its maximum point at 4 a.m. Those on the West Coast can get an earlier start on their viewing, with a start just after 11 p.m. and a 1 a.m. maximum.
In partial eclipses, a portion of the Moon is blocked by the Eerth's shadow, making it look like a bite has been taken out. Penumbral eclipses occur when the Moon passes through the faint outer shadow of the Earth, and they are barely visible.
Source: NASA