Updated

Updated · NBC Los Angeles · Aug 12

Griffith Observatory Opens Free August 27 Lunar Eclipse Viewing as 96% of Moon Faces Shadow

Updated

Updated · NBC Los Angeles · Aug 12

Griffith Observatory Opens Free August 27 Lunar Eclipse Viewing as 96% of Moon Faces Shadow

Q: What hidden secrets about Earth's atmosphere will the eerie glow of the upcoming almost blood moon reveal to skywatchers?

The eclipse’s eerie glow will mainly reveal the state of Earth’s atmosphere, not hidden features on the Moon. The Moon’s color during this deep partial eclipse — red, coppery, orange-yellow, brown or even gray — depends on how sunlight is filtered, scattered and bent through the air around Earth. That happens because when Earth blocks direct sunlight, some light still passes through the planet’s atmosphere and is refracted into Earth’s shadow. Shorter blue wavelengths are scattered away more efficiently, while longer red and orange wavelengths make it through, much like a global ring of sunrises and sunsets projected onto the Moon. This is why astronomers often describe a lunar eclipse as a visible test of atmospheric conditions. What skywatchers may “read” from the color is the amount of dust, smoke, clouds, haze and other particles in the atmosphere. Cleaner air can produce a brighter copper or orange glow. Heavy dust, wildfire smoke or volcanic aerosols can make the eclipsed Moon darker, duller or deeper red. Uneven coloring across the Moon can also show how different parts of Earth’s shadow are being lit. Because this eclipse will cover about 96% of the Moon at maximum, it should offer a strong display of those atmospheric effects even without reaching totality. In that sense, the “almost blood moon” will act as a natural snapshot of Earth’s air — a reminder that the colors seen on the lunar surface are really a reflection of conditions much closer to home.

Q: With 96% of the moon in shadow, will the remaining bright sliver completely shatter the illusion of a true blood moon?

No—the bright sliver should not completely ruin the effect. With about 96% of the Moon inside Earth’s umbra, this is a very deep partial lunar eclipse, and many observers will likely see something that looks very close to a blood moon, even if it is not technically a total one. The key difference is that a true blood moon happens only during totality, when the entire Moon is inside Earth’s dark central shadow. In this case, a narrow sunlit edge will remain, so the Moon will not become uniformly red. That bright rim will preserve the “partial” look, especially to the naked eye. Still, most of the lunar disk is expected to darken dramatically and may glow coppery red, orange, brown or gray depending on atmospheric conditions such as dust, smoke and how Earth’s atmosphere filters sunlight. Several astronomy sources describe this event as an “almost blood moon” because the covered portion should take on the same basic reddish tones seen in total lunar eclipses. In practice, the sliver will likely create contrast rather than destroy the spectacle. Observers may see a striking combination: a dim red-orange Moon with a thin bright crescent-like edge. Cameras and binoculars may make the red shading even more apparent than casual naked-eye viewing. So the illusion will be imperfect, but not shattered. For many viewers, it should still be one of the most blood-moon-like lunar eclipses until the next total lunar eclipse.

3 articles · Updated · NBC Los Angeles · Aug 12

Griffith Observatory will host free on-site and online viewing of the Aug. 27 partial lunar eclipse, with outdoor access from 7:25 p.m. to 11 p.m. in Los Angeles.
The observatory said the eclipse should be visible to the unaided eye across the region if skies are clear, and lunar eclipses can be watched safely without eye protection.
Key viewing moments include moonrise, the point of greatest eclipse and the end of the umbral phase; the building itself will stay open until 10 p.m., with restrooms available through 11 p.m.
Crowds are expected to be large and parking limited for the weather-dependent event, which comes as North America is set to see about 96% of the moon covered by Earth's shadow.