Search Nature Watch

Saturday, April 27, 2024

Umbraphilia!

 

Would the clouds cooperate during the total solar eclipse?

A total solar eclipse occurs when the moon, the sun, and the earth align such that the moon appears to completely cover the face of the sun from the earth’s perspective.  To see this astronomical phenomenon, you must be somewhere within what is called the path of totality.  About every 18 months or so, a total solar eclipse happens somewhere in the world, and on April 8, 2024 Central Texas was lucky enough to be in the path of totality.

Typically, the path of totality across the globe is around 9000 miles long, but only about 90 miles wide, and being in the very center of this path allows you to maximize the amount of time that totality lasts.  A total solar eclipse can last for several hours, but totality can only range from a few seconds to seven and a half minutes. Observers outside the path of totality may only see a partial solar eclipse. 

The first stage or partial eclipse.

There are five different stages that make up a total solar eclipse. The first stage is when the partial eclipse begins, or when the moon starts to become visible over the sun, looking like it has taken a bite out of it.  The second stage is when the total eclipse begins, when the moon covers the entire face of the sun, and you are now in the umbra, or the darkest part of the moon’s shadow. The third stage is totality, which is when the moon completely covers the sun and leaves only the sun’s corona visible. The midpoint of this stage is called the maximum eclipse. 

Totality or maximum eclipse!

During totality, the sky goes dark, the temperature falls, a light breeze picks up, and the birds and other animals go quiet. The fourth stage is when the total eclipse ends, and the moon starts moving away as the sun reappears.  The fifth and final stage is when the partial eclipse ends, as the moon is no longer visible over the sun.

Baily's Beads appearing in Stage 2, just before totality.

During the second and fourth stages, when the moon is just about to cover the sun or just starts to move away, those in the path of totality can have the chance to see two special effects, Baily’s beads and the diamond ring. About five seconds before and after totality, Baily’s Beads appear as little bead-like blobs of light at the edge of the moon, created by sunlight passing through the gaps in the mountains and valleys on the moon’s cratered surface. They are named after Francis Baily, an English astronomer who observed and described this effect in 1836. 

The diamond ring in Stage 4, just after totality.

About 10 to 15 seconds before and after totality, the solar corona or outer atmosphere of the sun becomes visible, and combined with a small remaining or emerging part of the sun’s disk dazzles like a diamond set in a ring.

Prominences seen during totality.

Sometimes, during totality, observers can see small, fiery structures around the obscured sun.  Typically, these are not solar flares, which are explosions on the sun’s surface that can launch massive clouds of plasma, but rather they are called prominences or longer-lived plasma structures that are smaller and not as explosive as flares.

One who is addicted to the glory and majesty of total solar eclipses is called an umbraphile, or ‘shadow lover.’  If you have personally experienced this amazing phenomenon of basking in the moon’s darkest shadow, you too may have contracted umbraphilia!