Why would a moon bleed red across the night sky, and why will this one persist so long? The Moon will traverse Earth’s umbra during the night of September 7–8, 2025, to exhibit an exceptionally lengthy total lunar eclipse of **82 minutes** one of the decade’s longest. Almost six billion individuals, about 71 percent of the world’s population, will be in the region of visibility, ranging from Asia, Western Australia, Africa, and over part of Europe. For the Americas, less favorable timing is given; the eclipse there will occur during the daytime.
When the Moon enters Earth’s central shadow, its bright silver face will fade and turn into a copper-colored red disk. It is due to light scattering physics. When the sunlight just touches Earth’s atmosphere, the shorter blue wavelengths are scattered out and longer red wavelengths get bent into the umbra. This **Rayleigh scattering**, the same process that colors the midday sky blue and the sunsets red, is the process that shades the light passing to the Moon. A reddish, even brownish red, can be the color of the eclipsing Moon under a dusty or cloud-covered atmosphere, such as after a volcano eruption.
The geometry of the eclipse is especially good. The path of the Moon will lie near the center of Earth’s shadow, extending totality. In Tokyo, totality will be from 2:30 to 3:52 local time; in Perth, from 1:30 to 2:52 a.m. Viewers in most of Europe can see the Moon rise already in shadow, a fleeting but spectacular event requiring a good, low eastern horizon.
It will not be alone. The Moon’s faint illumination at totality will make the less luminous celestial bodies visible. Saturn, at its close-to-opposition brightness, will be a golden dot near the Moon, its rings visible in even a small telescope. Neptune, a faint blue-green dot, will be visible too but will be a telescope or binocular object. For those who have tracking mounts, the alignment represents a once-in-a-lifetime opportunity to photograph a duo of planets and a blood moon.
Astrophotographers will need to get ready. The Moon’s light will dim by as much as eight stops from full illumination to the moment of totality, and settings will need to be adjusted constantly. Without a tracking mount, shutter speeds need to be shortened fractions of a second at longer focal lengths to prevent motion blur because of the Moon’s movement. A **400mm or greater lens** on a full-frame sensor will image the lunar disk with surface texture; shorter lenses can frame the Moon against a background, particularly at moonrise in Africa or Europe.
Smartphone photographers can get incredible images with the phone mounted on a telescope eyepiece via a stiff adapter and manual or “pro” mode for adjustment of ISO, aperture, and shutter speed. DSLRs and mirrorless cameras must be filmed in RAW to provide post-processing flexibility for noise reduction, sharpening, and precise color balancing to reveal the umbral glow’s subtle progression.
In Britain, the Moon appears eclipsed rising, totality lasting about 15 minutes later time is everything. Prospecting a location with an unobstructed view in the direction of the **100° azimuth** is essential. Thin haze will conceal the Moon near the horizon, so binoculars can help locate it when rising.
Others kept in the dark or on the wrong side of Earth will still be able to view the event via global live streams from such projects as The Virtual Telescope Project. But for others with clear blue skies, the combination of a long totality, a packed planetary background, and the bright red hue produced by Earth’s atmosphere will make this blood moon the decade’s highlight of the celestial calendar.
