The shortest total eclipse of the moon taking place during the entire 21st century will be visible in the predawn sky on the morning of April 4.
And most North Americans, especially those living in the western United States, are ideally located to watch the event.
A total lunar eclipse happens when the moon completely immerses itself inside the darkest part ( umbra) of the Earth’s shadow. The total phase of a typical eclipse lasts about one hour.
However, the total phase of Saturday’s eclipse begins about 4:48 a.m. and ends just five minutes later.
Some predictions suggest totality might stretch to eight to 12 minutes. The difference depends on how the fuzzy outer edge of the umbra is defined.
Regardless, this is still the shortest total eclipse of the moon until the year 2196.
This speed-dialed eclipse seems a natural fit to the fast food, fast cash, speed dating, instant credit, computer messaging and express oil changing culture embraced by the technology-driven Millennial and Generation X crowd.
So perhaps we should dedicate this warp-drive eclipse to them. Saturday morning is a perfect time to take the kids outside and share this event with our youngest generation. They will remember the adventure for a lifetime.
A total eclipse of the moon takes place when the moon is full and aligned with the Earth and sun.
Imagine drawing a straight line through three dots — with the middle dot being the Earth. That’s the cosmic fence line we need to instigate this eclipse.
Of the approximately 1,200 full moons occurring during the 21st century, only 85 will form a total eclipse. The remaining full moons will pass above or below the Earth’s shadow every 29 days as the moon orbits our planet.
The first hint of Saturday’s eclipse will begin at 3:15 a.m., as the curved outline of the Earth’s shadow begins covering the moon’s eastern (left) edge at a speed of about 0.6 miles each second.
When this partial phase begins, the moon lies about one-third above the southwest horizon.
All phases of the eclipse are easily seen with the unaided eye or through binoculars.
With each passing minute, the moon will nudge eastward, burying itself deeper inside the umbra until totally covered just before 5 a.m. This marks the beginning of totality — the orange-colored phase of the eclipse when no sunlight shines directly on the moon’s landscape.
When totality begins, the moon rests two hand-widths, held at arm’s length, above the western horizon.
During totality, the moon’s northern edge will shine brighter than the rest of the moon. This is because the moon’s north pole is skimming just inside the top of the Earth’s shadow, while the moon’s southern hemisphere glows a deeper orange because it’s closer to the umbra’s darker center.
If you were an astronaut standing on the moon, the surrounding cratered landscape, stretching beneath the blackness of space, would no longer appear ash gray but tinted copper and orange.
Through your helmet’s visor you would notice the night side of the Earth encircled by a thin reddish ring of light formed by the glow from a continuous band of sunrises and sunsets encircling the Earth about 250,000 miles away. Your thumb would just cover Earth.
Our planet’s atmosphere bends the color of these dusks and dawns into the shadow’s center to illuminate the eclipsed moon.
Totality will end at close to 5:03 a.m., when the upper left portion of the moon starts emerging from the umbra.
The partially eclipsed moon will set at 6:40 a.m. as the sun rises over the Blue Mountains.
If Saturday morning is cloudy, don’t worry. The fourth consecutive total eclipse of the moon visible during the past 18 months will occur Sept. 28. This time, the totality will last for more than an hour.