Category: Astronomy

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Ring of Fire

The Hinode satellite
captured this image of
an annular solar eclipse

Hinode is a Japanese mission
in partnership with NASA,
NAOJ, STFC, ESA, & NSC
Photo Courtesy NASA

Annular eclipse path for May 20, 2012
Courtesy Fred Espenak, NASA/GSFC

Hi, I’m Holly Strand.

On Sunday afternoon and early evening, the US mainland will experience its first solar eclipse of the 21st century. And Utahns will have first row seats.

During a total eclipse, the Earth, Moon and Sun are in perfect alignment with the Moon in the middle. For the Earthlings experiencing it, the sun’s surface is totally blocked by the moon and the sky darkens. However, sometimes the Earth-Moon-Sun alignment occurs when the moon is near its greatest distance from earth. When this happens, the moon has a smaller apparent size that is not large enough to cover the entire disk of the sun. Instead, a fiery ring of sunlight remains visible around the lunar edge. This is called an annular eclipse from the Latin word “annulus” meaning ring. And this is what some Utahns will see on Sunday.

To experience a total or annular eclipse you must be located within the eclipse path which is defined by the eclipsing moon’s shadow. The path of this Sunday’s eclipse is a 150-180 mile wide swath that begins near Hainan Island in southern China at sunrise on May 21. The center line of the eclipse path curves northeast, passing between Yokohama and Tokyo, before continuing across the Pacific. SW of the Aleutians the path traverses the International Dateline where suddenly it’s the day before- May 20. Then the path curves south and eastward striking the United States near the border of California and Oregon. Arching down through Nevada and Utah the path slices through the southwest before disappearing with the sunset in Texas.

The eclipse path encompasses the entire SW corner of Utah. Visitors to Zion, Bryce Canyon, Cedar Breaks and Lake Powell will experience full annularity. As will the inhabitants of St George, Milford, Kanab, Cedar City, Escalante and many other southern Utah towns. Don’t despair if you are outside the full eclipse path. Anywhere in Utah, you will still experience a very impressive partial eclipse.

Even though an eclipse is an amazing sight, it is not for human eyes! Most eclipse-burned retinas belong to children or young adults so be vigilant with young ones around. The common way to experience an eclipse is with a pinhole viewer with two pieces of stiff white cards. Punch a hole in one of the cards and– with your back to the Sun–hold the card up so that light falls through the hole, projecting the eclipsed sun’s image on to the other card. Do not look at the Sun through the pinhole!

If you have some shade trees, look at the images of eclipsed sun coming through the holes formed by the leaves. You may see little rings of light in the shadows. If the leaves have little bug holes, they will also act as pinhole projectors.

If for some reason you miss this Sunday’s show, you don’t have to wait long for another…in astronomical time anyway. For on August 21st 2017, North America will experience a total solar eclipse. The path will be just to the north of Utah in central Idaho and Wyoming. Total eclipses can draw a huge number of visitors from around the country and abroad. If you think Jackson hotels are expensive now just wait ‘til 2017!

For pictures, maps of the eclipse path and advice on viewing go to www.wildaboututah.org

Special thanks to Michelle Larson, astrophysicist at Utah State University, for her help with this Wild About Utah episode.

For Wild About Utah, I’m Holly Strand.

Credits:
Images: Courtesy NASA https://www.nasa.gov
Text: Holly Strand

Sources & Additional Reading


Fred Espenak’s Eclipse Web Site:
https://eclipse.gsfc.nasa.gov/eclipse.html

Interactive path of annularity or eclipse path of the May 20th eclipse.
https://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2012May20Agoogle.html

Map of May 20 eclipse path in Utah
https://home.cc.umanitoba.ca/~jander/ase2012/US3.png
See also the home page: https://home.cc.umanitoba.ca/~jander/

Enter a geographic location to find out about past and future eclipses: https://eclipse.gsfc.nasa.gov/JSEX/JSEX-NA.html

How to view:
https://earthsky.org/space/view-may-20-annular-eclipse-and-june-5-transit-of-venus-safely

Posted on

Of Shooting Stars

Audio:  mp3 Listen to WildAboutUtah

The Fallen Sky: An Intimate History of Shooting Stars
Cover Courtesy & Copyright © 2009 The Penguin Group

Holly: Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

Christopher Cokinos is the author of a new book, The Fallen Sky, published by the Penguin Group Press. It’s the story of meteorites and the impressions that meteorites make on the Earth and in the people who seek them out. Here’s Chris talking about falling stars:

Chris: On any clear night, under a dark enough sky, we can see shooting stars. We wish upon them even if we may not know what they are. It’s as if we’re eager to pin our chances on something strange and sudden.

A shooting star is not a star; it’s a meteor—the bright passage of a small grain or rock burning up through the air as it descends from space. If it’s big enough, it may drop a rock on the Earth itself—then it becomes a meteorite. In space, these objects are called meteoroids.

Every mid-August, our skies are graced by a shower of shooting stars—the Perseids. This is when Earth intersects the spindrift tail of the disintegrated Comet Swift-Tuttle, and we see these dusty grains streaking through the sky, too small to ever reach us.

They’re called the Perseids because the meteors appear to originate from the constellation Perseus, but these shooting stars can appear in any part of the sky.

Meteors travel very fast, from between 7 miles per second to 44 miles per second, and even one the size of a raisin can produce a huge fireball.

But if you see one that big during the Perseids, it’s not a Perseid—it’s a random meteor, originating from the asteroid belt or even the Moon or Mars.

This year, the moon will interfere with viewing the shower, but you can still see quite a few Perseids from the late evening of August 11 through the morning of August 12.

The best way to watch is to recline on the ground or on a chaise so you have a wide view of the sky, preferably away from city lights. Have snacks, water and appropriate clothing and maybe some bug spray. Don’t use binoculars or a telescope as they restrict your field of view.

To learn how to make simple but scientifically useful observations, go to the American Meteor Society website at www.amsmeteors.org.

Of course, though it may not be scientifically useful, when you see a shooting star—feel free to make a wish.

Holly: Thanks, Chris. For listeners in the Logan area, check out the Star Party at the American West Heritage Center on August 14th. For more details see awhc.org

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Credits:

Image: Book Cover Courtesy & Copyright © 2009 The Penguin Group

Text: Chris Cokinos

Sources & Additional Reading:

Cokinos, Christopher. 2009. The Fallen Sky: An Intimate History of Shooting Stars. Penguin Group, Inc.

“Weaving natural history, memoir, and the stories of maverick scientists, daring adventurers, and stargazing dreamers, this epic work takes us from Antarctica to outer space to tell the tale of how the study of meteorites became a scientific passion.”

https://www.amazon.com/Fallen-Sky-Intimate-History-Shooting/dp/1585428329 (Accessed August 11, 2009)

https://www.amazon.com/Fallen-Sky-Intimate-History-Shooting/dp/1585427209

Posted on

Perseids Meteor Shower

In this 30-second exposure, a meteor streaks across the sky during the annual Perseid meteor shower, Wednesday, Aug. 11, 2021, as seen from Spruce Knob, West Virginia. Courtesy NASA, Bill Ingalls, Photographer
In this 30-second exposure, a meteor streaks across the sky during the annual Perseid meteor shower, Wednesday, Aug. 11, 2021, as seen from Spruce Knob, West Virginia.
Courtesy NASA, Bill Ingalls, Photographer
The Perseids meteor shower is one of the most popular events of the year for sky watchers. A meteor shower is simply an increase in meteor activity which is produced when the Earth passes through a trail of debris that is also in orbit about the Sun.

Perseids debris comes from the Comet Swift-Tuttle, the largest object known to make repeated passes near the Earth. Its nucleus is about 6 miles across. Most of its meteoroids are the size of sand grains; a few are as big as peas or marbles. When they enter Earth’s atmosphere, they are called meteors. Almost none hit the ground, but if one does, it’s called a meteorite.

The Perseid shower is detectable from July 25-Aug 20, but meteor activity rises sharply around Aug. 12. For example, on the 25th you can expect to see a meteor every hour. Maybe 5 an hour by the 1st of August, up to 15 an hour by August 10th. But then on August 12, the number will spike to 50 -80 /hour and in some years up to 200! Then the number will quickly subside until Aug 20, when you’ll be back to 1 an hour.

Perseid meteoroids are fast. They enter Earth’s atmosphere at roughly 133,000 mph– or 60 km per second. They also make a sound! Fast-moving meteoroids ionize the air in their path leaving behind a trail that can briefly reflect radio wave from TV stations, RADAR facilities or AM/FM transmitters. A “radio meteor” is the short-lived echo of a radio signal that bounces off such a trail. Scientists at the NASA Marshall Space Flight Center in Huntsville, AL have established a radio meteor monitoring system. Here’s what a typical echo sounds like against some background static:

https://www.spaceweather.com/meteors/audio/geminidecho.wav (Editors note: Content AWOL as of 8/2021
Original article quoting sound found at https://www.spaceweather.com/glossary/nasameteorradar.html)
See NASA Radio Meteors: https://science.nasa.gov/search?search_api_views_text=radio+meteors (accessed August, 2021)

Hmmm… Kind of reminds me of a whale song.

This year, August 12th features a gibbous moon which means lunar glare will wipe out the path of the smaller meteroids . You’ll want to find a spot in the moonshade which will minimize glare. Or you can watch during predawn moonless hours on August 12th which will be the peak of this year’s show. No worries for those of us who can’t stay awake past midnight though. There will still be so-called shooting stars even while the moon is out—just less than when the moon has set. Furthermore, Jupiter is almost opposite to the sun with the planet coming physically closest to the Earth in its orbit . That means good viewing as Jupiter will appear very large. Look for it together with the moon in the constellation Sagittarius in the southeast sky. Depending upon your viewing equipment, you may be able to see some of Jupiter’s moons as well as the Great Red Spot, which is a gigantic hurricane-like storm twice the size of Earth on Jupiter’s surface.

For a sociable viewing experience, sky watchers in Northern Utah are invited to the Stokes Nature Center/American West Heritage Center Star Party August 12th from 9-1. We’ll have powerful telescopes, experienced interpreters, and all sorts of fun activities for adults and families. For more information see www.logannature.org or www.awhc.org

Credits:


Photo: Courtesy NASA, Bill Ingalls, Photographer, https://www.nasa.gov/image-feature/behold-the-perseid-meteor-shower
Text: Holly Strand, Stokes Nature Center

Additional Reading

Harbaugh, Jennifer, How many Perseids will I see in 2021?, NASA, August 9, 2021 https://blogs.nasa.gov/Watch_the_Skies/tag/perseids-meteor-shower/

McClure, Bruce, Perseid Meteor Shower 2021 Reaches Its Peak, EarthSky, August 10, 2021, https://earthsky.org/astronomy-essentials/everything-you-need-to-know-perseid-meteor-shower/

Pop! Ping! Perseids! Science@NASA (accessed July 31, 2008)
https://science.nasa.gov/newhome/headlines/ast13aug99_1.htm

Philipps, Tony. 2008. The 2008 Perseid Meteor Shower Science@NASA (accessed July 31, 2008)

Radio Meteor Listening.
https://www.spaceweather.com/glossary/forwardscatter.html (accessed July 31, 2008)

Ridpath, Ian. Oxford Dictionary of Astronomy. 1997.
NY: Oxford University Press

Harbaugh, Jennifer, How many Perseids will I see in 2021?, NASA, August 9, 2021 https://blogs.nasa.gov/Watch_the_Skies/tag/perseids-meteor-shower/

McClure, Bruce, Perseid Meteor Shower 2021 Reaches Its Peak, EarthSky, August 10, 2021, https://earthsky.org/astronomy-essentials/everything-you-need-to-know-perseid-meteor-shower/