2017-08-10 / Nature

Sun and Star ‘Shows’ to Light Up and Darken the August Skies

By Charles Avenengo


On Monday, Aug. 21 the moon’s shadow will race across the United States, from Oregon to South Carolina. The path of this shadow, also known as the path of totality, is where observers will see the moon completely cover the sun. On Monday, Aug. 21 the moon’s shadow will race across the United States, from Oregon to South Carolina. The path of this shadow, also known as the path of totality, is where observers will see the moon completely cover the sun. All of us have looked at the sky and wondered about things. Sometimes, at night, our wonder has drifted to the celestial objects themselves, and in the day, we may have pondered the sun.

This month there will be some spectacular natural “fireworks” to behold and a total eclipse of the sun, which has not occurred since 1979. This “all-American” phenomenon will be accessible to us, all over the country, in different forms and to differing degrees.

The Perseids

After the current waning gibbous moon, the brightest night objects will be two planets: Venus, the most brilliant, which currently graces the early morning eastern sky, and Jupiter, now visible in the southeast evening sky, centered in the constellation of Virgo. Both are much brighter than Spica, the brightest star.

Peaking on Saturday night, Aug. 12, is the annual Perseids meteor shower, considered the best display of the year of shooting stars.

Nevertheless, observers of this year’s version of the annual summer spectacle might face some difficulties.

According to Francine Jackson, director of Brown University’s Ladd Observatory in Providence, “It doesn’t appear as if this year will be the best to observe them. Although things often change overhead, the waning gibbous moon will be in a position to overpower many of the dimmer meteors, so your average hourly rate will most likely be less than hoped for.”

Despite the less-than-optimal prognostication for the meteor shower, however, Jackson did offer some encouragement. “Because they occur during the summer, when more people are outside at night, there’s always the possibility to see some. Remember, too, that although Aug. 12 is considered the ‘peak’ day to observe, there will be some meteors visible from now until later in the month. Also, the constellation Perseus is considered the ‘radiant,’ the point where most meteors of this shower appear to originate. Perseus rises around midnight right now, so your best time to watch for them is late in the evening.”

Meteor showers are named after the constellation from which they originate, as in the “Perseids,” for “Perseus.” In the case of the Perseids, every year at this time, the earth’s rotation encounters cosmic “dust,” remnants from the exploded Swift-Tuttle Comet. Meteor showers are measured in predicted amounts seen per hour. Typically, each year at peak, the Perseids averages about 60 shooting stars per hour. Jackson also said most meteors are “lima bean-sized.”

A Total Solar Eclipse

Day will be turned into twilight, although it will occur mostly south of New England, with the total solar eclipse on Monday, Aug. 21.

Dubbed “The Great American Eclipse,” it will be the first all-American eclipse since 1918.

On Aug. 21, the umbra, which is the dark shadow of the moon, will make “landfall” at 10:15 a.m. Pacific Coast Time in Oregon and travel southeast across America. The 40- mile wide “Totality Zone” of darkness will race 2,500 miles across the United States for 94 minutes at a speed of 1,600 mph, exiting onto the Atlantic from coastal South Carolina at 2:49 p.m. EST. Although Rhode Island and most of America won’t have a direct “hit” of this exciting phenomenon, locally the maximum partial eclipse will occur at 2:47 p.m. with 65 percent of the sun obscured.

When the sun is obscured by the moon’s umbra, day turns to twilight and temperatures fall. Huge streamers might streak across the sky.

As it travels in a swath across the United States, the “Great American Eclipse” will be in range for over 225 million Americans who live within a one-day drive. Hotels in many locations of the 12 states in the Totality Zone have long been booked to capacity. Officials expect major traffic jams. Those who see it will observe the phenomenon for about two minutes. Astronomers said the longest time the sun will be obscured will be in southwest Kentucky, where the total eclipse will last two minutes, 40 seconds.

The event promises to be dramatic. But if you can’t make the 16-hour drive to South Carolina for the blackout, don’t despair. If you can hang in there for seven years, the next solar eclipse in the United States will be in April, 2024, and this one will go directly through parts of New England.

Stay tuned.

Naturalist Charles Avenengo has been chasing Aquidneck Island wildlife for more than 40 years.

Observation tips

Francine Jackson of the Ladd Observatory in Providence offered tips on how to watch a shooting star gallery. “Observing can be anywhere. You don’t have to go to a special place. As long as you can see the sky, your backyard is always a good place to look up. All you need is a comfortable chair or a blanket, and a fairly good eastern horizon, although sporadic meteors (not associated with the material from Comet Swift-Tuttle that created this shower) can be observed coming from anywhere in the sky. No equipment is needed. In fact, binoculars might cause you to miss some. Just being able to turn your head all around will cause you to ‘bump’ into many more of these elusive objects.”

Safety

Never look directly at the sun. Use special eclipse glasses available from retailers.

Observatories in R.I.

.Ladd Observatory, 210 Doyle Ave., Providence. Open to the public on Tuesday evenings, weather permitting.

.Frosty Drew Observatory, 61 Park Lane, Ninigret Park, Charlestown. Open to the public Friday evenings, weather permitting.

.Margaret Jacoby Observatory, Community College of Rhode Island Knight Campus, Warwick. Times vary for public. Check their website.

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