A lunar eclipse and a \u201cblood moon\u201d will occur on Sept. 7. Despite the dramatic name, a blood moon refers to the deep red hue the moon takes on when it passes through Earth\u2019s shadow during a lunar eclipse, known as the eclipse\u2019s totality point.<\/p>\n
This weekend\u2019s celestial event will be visible to an estimated 85% of the world\u2019s population<\/a> \u2014 although no one in the Americas will be able to see it. Lunar eclipses only happen twice a year on average \u2014 the upcoming one is the second and final of 2025, and the next is expected to occur on March 3, 2026, according to NASA<\/a>.<\/p>\n Here\u2019s what to know about Sunday\u2019s upcoming eclipse.<\/p>\n What is a lunar eclipse?<\/p>\n A lunar eclipse happens when the Earth, the moon and the sun are perfectly aligned in orbit, but the Earth is positioned between the moon and the sun. Earth\u2019s shadow blocks the sunlight from reaching the moon\u2019s surface, causing it to dim, according to NASA<\/a>. (In contrast, a solar eclipse<\/a> happens when the alignment is similar, but the moon blocks the sun\u2019s light from reaching Earth, NASA explains.)<\/p>\n Lunar eclipses occur when the moon is at its full moon phase<\/a> \u2014 when the moon\u2019s face is fully visible from Earth. Even though the moon enters its full moon phase every month, an eclipse only happens when the moon is inclined at a certain angle when its orbital path crosses Earth\u2019s, according to Time and Date<\/a>, a site that tracks astronomy and time zones.<\/p>\n What is a blood moon?<\/p>\n The moon takes on this particular shade of red because the only sunlight that reaches its surface comes from the edges of the Earth. Air molecules in the Earth\u2019s atmosphere \u201cscatter out most of the blue light,\u201d NASA explains<\/a>, which means the \u201cremaining light reflects onto the Moon\u2019s surface with a red glow.\u201d<\/p>\n When and where can viewers watch the eclipse?<\/p>\n The lunar eclipse will start at 11:28 a.m. ET, and totality will happen at 1:30 p.m. ET, according to Space.com<\/a>. The eclipse is expected to last roughly five hours and 27 minutes, while the blood moon will be visible for 82 minutes during that time, Time and Date said<\/a>.<\/p>\n The entire eclipse will be visible to people in Australia, Asia, Africa and Eastern Europe; while stargazers in parts of Western Europe, such as the U.K. and Spain, and the easternmost parts of Brazil will catch some glimpses, but not the full eclipse, Space.com reported.<\/p>\n People in the Americas will not be able to see anything because the moon will be below the horizon and on the opposite side of the Earth during that time, Space.com said.<\/p>\n