Witness Total Lunar Eclipse January 20-21

Go outside on a Sunday night, January 20, and watch the earth cast a shadow onto the moon through Monday morning. The total lunar eclipse happens at favorable viewing hours when the moon is above the horizon, letting you witness the entire celestial apparition if you stay up late.

KEY TIMES

See the animation at https://www.timeanddate.com/eclipse/in/usa/south-bend for local circumstances around South Bend, IN--where the eclipse is visible from start to finish--or adjust for your location's time zone. The depiction shows times of key eclipse stages, with the local highlights starting at 10:34 pm EST when the partial eclipse becomes obvious and from 11:41 pm to 12:43 am EST when the moon is wholly within the shadow of earth--totality.

The earth essentially casts two shadows through which the moon passes--a faint outer ring called the penumbra and a darker inner ring called the umbra. See the Lunar Eclipse Shadows activity described below for a description of how to simulate the two shadows. Few people can readily discern the outer penumbra, so I emphasize it less than the darker umbral shadow.

The darkness and color of the eclipsed moon depends on factors such as atmospheric dust (e.g., from recent volcanoes) and how deep into the shadow the moon dips. For this 2019 event, no part of the moon quite reaches the midpoint of the shadow.

Illustration shows moon location relative to background stars, many of which will be washed out in the glare of the full moon's glare. Star size suggests relative brightness.

January 20-21, 2019 (Eastern Standard Time)

9:36 pm Penumbral Eclipse begins; faint outer shadow is harder to discern; full moon becomes muted

10:34 pm Umbral Eclipse begins; at the "public start" it's more obvious that the eclipse is underway; a bite appears taken out of the moon

11:41 pm Total Eclipse begins; moon is reddish while totally in earth's umbral shadow; red is the refracted light of concurrent sunsets around the earth

12:12 am Maximum eclipse; essentially the midpoint of the spectacle

12:43 am Total Eclipse ends; brighter moon edge appears

1:50 am Umbral Eclipse ends; I start packing up gear, for the outer shadow is hard to notice

2:48 am Penumbral Eclipse ends; end of the show

For a visual reminder of key times in EST, see 2019 Lunar Eclipse Time Frames (PDF).

ALSO UP

While you're waiting around for the eclipse to become obvious, check out what else is in the sky.

In the winter, the constellation Orion the hunter dominates the southern sky with its three belt stars pointing down and left to Sirius, the brightest star in the night sky.

Above the moon are a pair of stars that look like they belong together. What constellation do they dominate? If you saw two seemingly identical people you may think they are what--twins? The pair of stars are the Gemini twins--Castor to the north and Pollux to the south.

Of course, it's a full moon so the sky is bright. But look nearby to see if you can see a change in the star count when comparing the fully illuminated moon and the fully eclipsed moon.

Down and left of the moon a few degrees is the Beehive Cluster, a compact bundle of stars that delight in binoculars and are on the cusp of being visible to the naked eye. Look for the cluster at 9:30 pm on Sunday when the moon is bright, and then look again mid-eclipse at midnight. Any difference?

Check the darkness of your sight. Can you see the Milky Way rather high overhead? And while you're craning your neck upward, look for the tight bundle of visible stars that define the Pleiades or the Seven Sisters.

ACTIVITY

Try this Lunar Eclipse Shadows activity in front of car headlights. First, lean against one headlight blocking it out while casting light on globe. Move white moon through shadow. Then allow both headlights to cast light on globe and compare shadows. Note distinction of penumbra with a light source that has dimension, as compared to the single-headlight point of light.

https://www.nightwise.org/single-post/2014/03/17/Lunar-Eclipse-Shadows

2019

Looking forward, July 20 will mark the 50th anniversary of the Apollo 11 moon landing. Re-enact the first lunar landing with a group of kids; see Land on the Moon 50 Years Later.

A transit of Mercury occurs November 11. The innermost planet Mercury zips directly in front of the sun, visible only with sun-safe magnification. This is not a naked eye event; proper eye protection required. After witnessing a transit of Mercury, Edmund Halley showed how the transit method could be used to measure size of the solar system. Halley's prediction was famously tested in ensuing transits of Venus.

Featured Posts
Recent Posts
Search By Tags
 
© 2020 Chuck Bueter