Schematic diagram of the shadow cast by the Earth. Within the central umbra shadow, the Moon is totally shielded from direct illumination by the Sun. In contrast, within the penumbra shadow, only a portion of sunlight is blocked.
The longest lunar eclipse in a decade is going to happen later today, but unfortunately it won’t be visible in North America. If you’re in other parts of the Northern Hemisphere, though, you can spend nearly two hours viewing it. National Geographic has the details:
Wednesday night the full moon will plunge into the longest and deepest total lunar eclipse in more than a decade.
Sky-watchers across most of the Eastern Hemisphere will be able to watch the lunar disc turn stunning shades of orange and red as the moon becomes engulfed within the darkest part of Earth’s shadow for almost two hours.
“The path that the moon is taking through Earth’s shadow is almost directly through [the shadow's] center, making for the longest possible path and so the longest duration,” said Ben Burress, staff astronomer at the Chabot Space & Science Center in Oakland, California.
