What is a lunar eclipse?
A lunar eclipse is when the Earth comes between the sun and the moon. This means the full rays of the sun get blocked by the Earth, causing the shadow of the Earth to darken the moon.
A total lunar eclipse means the whole of the moon gets cast in darkness.
The moon isn’t exactly invisible, however. While the Earth’s atmosphere scatters away blue light, the red light passes through the Earth’s atmosphere and refracts toward the moon, causing a reddish glow. The more clouds or dust in the Earth’s atmosphere, the redder the moon will be.
When can I see it?
According to NASA, the moon will start entering the Earth’s partial shadow shortly after 9:30 p.m. ET on Sunday night. You’ll be able to see a slight darkening of the Moon at around 10:28 p.m. ET. The Earth’s full shadow will cover the moon an hour later.
The eclipse will peak at 12:11 a.m. ET Monday. NASA says the moon will start leaving the Earth’s shadow at 12:54 a.m. and emerge completely at 1:55 a.m.
You can observe lunar eclipses without protective equipment. You will get a much better view looking with binoculars or, better yet, a telescope.
What if I miss it?
The next total lunar eclipse visible from the U.S. happens later this year on Nov. 8, 2022.
May 15’s eclipse is the second of the year but the first visible from the U.S. A partial eclipse of the sun already happened on April 30. Another will take place on Oct. 25, but the U.S. won’t be able to see it.