Date: February 8, 2009
Title: The Paragould Meteorite of 1930
Podcaster: Kenneth Renshaw
Description: Although much astronomical research is done by looking at things far away, some is performed here on Earth with meteorites that unexpectedly provide us with rock specimens from millions of miles away. On February 17, 1930, one of the largest of these hit near a small town of Paragould, in Northeast Arkansas. At 820 pounds, one of the samples was, at that time, the largest to ever be seen and recovered. Another, at 70 pounds, hit nearby, with a possible third not yet found. This podcast will describe this fall, as well as meteorites, meteor showers, and related phenomena.
Bio: Kenneth Renshaw is a college music instructor, piano teacher/tuner/technician, church choir director/pianist, photographer and videographer from the small town of Piggott, Arkansas (near his birthplace, Paragould, the site of this historic meteorite fall). He graduated from Southern Baptist College and Arkansas State University with Associate, Bachelor, and Masters degrees in music education, but has had the hobby of amateur astronomy since the age of 16. He is married to Rachel Burden, with 2 stepdaughters, Melody, 16, and Liberty, 15.
Today’s Sponsor: This episode of ’365 Days of Astronomy” is sponsored by the American Astronomical Society, the major organization for professional astronomers in North America, whose members remind everyone that One Sky Connects Us All. Find out more or join the AAS at http://aas.org/
Although the opening song of this podcast tells us that we, as astronomers, study things far far away, sometimes Mother Nature drops a specimen for astronomical research right in our back yard. Such happened about 4 O’clock one morning, 79 years ago in Northeast Arkansas, causing a cattle stampede and the rude awakening of the small town of Paragould.
Hi, I’m Kenneth Renshaw, a native of Paragould, and a volunteer Solar System Ambassador and Saturn Observation Campaign member for NASA’s Jet Propulsion Laboratory.
At 4:08 AM, February 17, 1930 (a bit before I was born, I might add, and, coincidentally the very day before Clyde Tombaugh discovered Pluto), 3 large sonic booms woke the residents of Paragould, Arkansas. The series of large pieces of a meteorite was seen in several states in the central U. S., with some people reporting a plane going down. That morning, the, at that time, largest meteorite ever observed in the world falling and then recovered slammed into a field Southwest of Paragould, creating a 10 foot deep hole. It was 820 pounds. Another piece hit about 2 miles away, and was about 70 pounds. A possible third piece was seen and heard, but has never been recovered. The 820 pound piece was eventually sold to the Field Museum in Chicago, and is now on loan to the University of Arkansas in Fayetteville. Pieces of both finds are in a number of museums and labs, with a very small amount in private hands. I have a small piece that I use for my presentations in schools.
Before I go on, a few definitions are in order: a meteoroid is a rock or metallic object in space before it hits the earth, a meteor is the light of an object as it falls (a bright trail of light from the object burning up in the atmosphere-the friction of the object traveling through air at several miles per second), while a meteorite is the object (if any) that survives the fall. A meteor shower is when the earth passes through the debris of a comet’s orbit, creating a fairly predictable flurry of meteors at about the same time each year, with very few surviving the trip to the ground.
The Paragould meteorite, as well as many that strike the earth on a daily basis, came from the asteroid belt between Mars and Jupiter. Occasionally, the massive gravity of Jupiter changes the orbit of an asteroid and sends it into an earth-crossing path, where it may eventually strike our planet. Sometimes, meteorites strike the Moon or Mars sending debris from those objects flying off at escape velocity. These rocks, floating around in space, can also eventually strike the earth. I have in my collection meteorites that have been chemically identified to have originally been part of the Moon and Mars. One of the Mars rovers, in fact, photographed a meteorite that struck that planet. Some meteorites, and most so-called “shooting stars” and meteor showers, however, are originally from comets, rather than the asteroid belt, when the earth crosses their path. All of the objects that make it to the ground give scientists hands-on material to study, giving us information about the origins of the planets, and the pristine conditions that existed in the early years of the Solar System.
On about every acre of the earth, there is a small amount of meteorite material, although the Paragould fall of 1930 was much more massive that is usually found, now the 4th largest stony meteorite in the world. Meteorites are stony, iron, or stony-irons in composition. The Paragould meteorite was made of stone.
The asteroid belt is leftover material from the formation of the Solar System. The Kuiper belt, beyond the orbit of Neptune, as well as the Oort Cloud, much further away at 10,000 times the Earth’s distance from the Sun, are also leftover material. All of this material is relatively unchanged since the formation of the planets, giving us a valuable tool in studying the chemistry of the early Solar System. The nearby asteroid belt of rocky material is usually the source of large meteorites, while the Kuiper Belt and Oort Cloud is composed more of water ice, and is the source of comets that occasionally visit the inner Solar System and display spectacular gas tails. The Kuiper Belt, 30-80 times the Earth’s distance from the Sun, is usually the source of short period comets, such as Halley’s with a 76 year orbit, while the long-period comets, visiting the inner Solar System only once in thousands of years, come from the Oort Cloud. The Kuiper Belt is close enough that large objects can be seen, such as Pluto, recently renamed a Dwarf Planet member of the Kuiper Belt, rather than one of the Major Planets. As I mentioned before, most meteor showers are sand-sized particles from comets, while the larger iron or stony meteorites that strike the earth intact usually come from the asteroid belt.
Sometimes, a comet nucleus itself can be on a collision course with the earth, with disastrous results. In 1908, a comet nucleus was believed to have hit in Siberia, near the Tunguska River, although the nature of the object is still under debate. It knocked down trees for tens of miles around, but left little debris to study. It is believed the comet nucleus or asteroid exploded above the ground, with just a shock wave doing the damage. Very few people populated that area, so there were no fatalities and few observers. On rare occasions, once in millions of years, a massive comet or asteroid can hit the earth with devastating results. An object, about the size of a small city, hit the Yuchitan Peninsula of Mexico about 65 million years ago, and was the possible trigger of the extinction of many species, including the dinosaurs. Although this type of mass disaster is rare, an increasing number of astronomers and spacecraft are dedicated to the detection and fine-tuning the orbital trajectory of the thousands of “Near-Earth Objects”, asteroids that actually cross the Earth’s orbit, that could spell a major disaster if they hit either land or an ocean of the Earth. As far as recorded history, there have been extremely few injuries and no human deaths reported by meteorites, although an unfortunate dog was reported killed in Africa once. This is due to the relative rarity of a meteorite or comet particle surviving the atmospheric entry and the vast square mileage of our planet. However, with any object falling at such rates of speed, the tiny potential for injury or even disaster is always there.
For more information on the Paragould meteorite, see my article in the Encyclopedia of Arkansas online at www.encyclopediaofarkansas.net. Navigate to the article titled “Paragould Meteorite”.
For more information on a free presentation within the U.S. by one of NASA’s Solar System Ambassadors, see www2.jpl.nasa.gov/ambassador/index.html. Or, for a presentation by the Saturn Observation Campaign, go to soc.jpl.nasa.gov/index.cfm.
A happy new year 2009 to everyone.
End of podcast:
365 Days of Astronomy
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