Perseids Meteor Shower

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:

http://www.spaceweather.com/meteors/audio/geminidecho.wav

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 Science.NASA.gov: http://science.nasa.gov/headlines/y2006/07aug_perseids.htm

Text: Stokes Nature Center:

Sources & Additional Reading

Pop! Ping! Perseids! Science@NASA (accessed July 31, 2008)
http://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.
http://www.spaceweather.com/glossary/forwardscatter.html (accessed July 31, 2008)

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

Red Rock Country

Chinese Wall at Bryce Canyon National Park
Courtesy NPS.gov
http://www.nps.gov/brca/

Straddling the 4 corners region is a massive geologic province known as the Colorado Plateau. Varying from 5 to 10,000 feet in elevation the region covers an area larger than the state of New Mexico, and is composed of thick horizontal layers of sedimentary rock . Terrain here is flat compared with Basin and Range country to the west and the Rocky Mountains to the east. Yet wind and water have whittled Plateau rock into dramatic cliffs and steps as well as fanciful domes, towers, turrets, and arches. The Plateau is dissected by the Colorado River and its tributaries exposing a deep and colorful geologic history. A predominance of red bed deposits in the central area of the Plateau has prompted the nickname “red rock country.”

So what’s behind the spectacular hues for which Utah is so famous? The color of rock is primarily influenced by trace minerals. The red, brown, and yellow colors so prevalent in southern UT result from the presence of oxidized iron–that is iron that has undergone a chemical reaction upon exposure to air or oxygenated water. The iron oxides released from this process form a coating on the surface of the rock or rock grains containing the iron.

Just think of what happens to a nail when you leave it outside. Upon prolonged exposure, the iron in the nail oxidizes and rust is formed as a coating on the surface of the nail. So basically what we have in red rock country is a lot of rusting sandstones and shales. Hematite is an especially common mineral form of iron oxide in Utah, the name coming from the Greek word “heama” or red blood. It only takes a tiny bit of hematite make a lot of red rock.

Geologists refer to rock layers of similar composition and origin within a given geographic area as “formations.” Certain formations in Utah are especially known for their beautiful reds or pinks. The Permian Period gave us Organ Rock shale which caps the buttes and pinnacles of Monument Valley. The deep ruddy browns of the Moenkopi formation were formed in the Triassic. In the early Jurassic, eastern Utah was a vast sea of sand with wind-blown dunes. These dunes became the red bed deposits of the Wingate Formation which today forms massive vertical cliffs. Entrada sandstone, from the late Jurassic, forms the spectacular red, slickrock around Moab.

Well anyway, now you know what I’m thinking of when I hear Utah referred to as a Red State. I’m picturing the extraordinary beauty of the red, salmon and rust- brown rocks that help to form the massive geologic layer cake in the south and east of our state.

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

Credits:
Photo: Courtesy NPS.gov: http://www.nps.gov/brca/
Text: Stokes Nature Center: Annalisa Paul

Sources & Additional Reading

Chan,Marjorie A. and William T. Parry Rainbow of Rocks . Public Information Series 77. Utah Geological Survey. http://geology.utah.gov/online/pdf/pi-77.pdf (Accessed July 2008)

Geology Underfoot in Southern Utah by Richard L. Orndorff, Robert W. Wieder, and David G. Futey, Missoula, MT Mountain Press Publishing Company, 2006, http://mountain-press.com/item_detail.php?item_key=366

Chronic, Halka. Roadside Geology of Utah. Missoula, MT Mountain Press Publishing Company, 1990 http://mountain-press.com/item_detail.php?item_key=48

Fillmore, Robert, The Geology of the Parks, Monuments and Wildlands of Southern Utah, University of Utah Press, 2000, http://content.lib.utah.edu/cdm4/item_viewer.php?CISOROOT=/upcat&CISOPTR=1328

Roadrunner in a Tree

Click for a larger view of a Greater Roadrunner on a Joshua Tree, Beaver Dam Slope in Washington County, UT. Courtesy and Copyright 2013 Jeff Cooper
Roadrunner on Joshua Tree
Geococcyx californianus
Beaver Dam Slope, Washington County, UT
Courtesy & Copyright 2013 Jeff Cooper
Neovistabirding.blogspot.com

“A roadrunner up in a tree? Couldn’t be!” was the comment I got upon describing this unusual sighting to some BLM employees in St. George, Utah. But sure enough, there it was, most likely a juvenile trying out it’s new wings as it’s lesser siblings scrambled through the desert scrub near a wet hollow. I too was amazed to see this quirky bird in a tree, but then stories I had accumulated from those who have lived in roadrunner territory bore testimony to its strange ways.

Their ungainly and rather comical appearance, combined with their eccentricities, have endeared them to many, and find myself no exception. And yes, as you have heard, they are very quick on their feet attaining sustained ground speeds of 17 MPH, not quite as fast as Canis Latrans, the wily coyote. Another peculiarity- for whatever reason, they have a propensity for running into buildings, perhaps hoping to corner their prey.

A member of the cuckoo family, the Roadrunner is uniquely suited to the hot desert environment found in southern Utah. This is because of a number of physiological and behavioral adaptations. Its carnivorous habits offer it a large supply of very moist food. It reabsorbs water from its feces before excretion. A nasal gland eliminates excess salt instead of using the urinary tract like most birds. An it reduces its activity 50% during the heat of midday.

Its extreme quickness allows the roadrunner to snatch a humming bird or dragonfly from midair. Snakes, including rattlers, are another favorite food. Using its wings like a matador’s cape, a roadrunner snaps up a coiled rattlesnake by the tail, cracks it like a whip and repeatedly slams its head against the ground until lifeless. It then swallows its prey whole, but is often unable to swallow the entire length at one time. This does not stop the Roadrunner from its normal routine. It will continue to meander about with the snake dangling from its mouth, consuming another inch or two as the snake slowly digests.

I can scarcely wait for my next encounter with the roadrunner!

Credits:

Photo: Courtesy and Copyright 2013 Jeff Cooper Jeff Cooper
Neovistabirding.blogspot.com

Text: Bridgerland Audubon Society: Jack Greene

For More Information:

Desert USA – The Roadrunner, http://www.desertusa.com/road.html (accessed 22 July 2008)
Animal Diversity, University of Michigan Museum of Zoology, Geococcyx californianus –
greater roadrunner, http://animaldiversity.ummz.umich.edu/site/accounts/information/Geococcyx_californianus.html