Meteors and Meteorites - Visual Meteors, Sporadic Meteors, Meteor Showers, Meteorites, Classification, Risk Assessment
meteoroid atmosphere vaporized produced
The word meteor is derived from the Greek meteron, meaning something high up. Today, however, the term is used to describe the light phenomena produced by the entry of objects into Earth's atmosphere. A meteoroid is defined to be any solid object moving in interplanetary space smaller than a few meters in diameter. A visual meteor, or shooting star, is produced whenever a sandgrain-sized meteoroid is vaporized in Earth's upper atmosphere. If a meteoroid survives its passage through the atmosphere, without being fully vaporized and falls to the ground, it is a called a meteorite.
Additional Topics
Upon entering Earth's upper atmosphere, a meteoroid begins to collide with an ever-increasing number of air molecules. These collisions will both slow the meteoroid down and heat its surface layers. Some of the meteoroid's lost energy is transformed into light; it is this light we observe as a meteor. As the meteoroid continues its journey through the atmosphere, its surface layers b…
On any clear night of the year an observer can expect to see about 10-12 sporadic meteors per hour. Sporadic meteors can appear from any part of the sky, and about 500,000 sporadic meteoroids enter the Earth's atmosphere every day. Meteor activity is often described in terms of the number of meteors observed per hour. The observed hourly rate of meteors will be dependent upon the prevalent …
Meteor showers occur when Earth passes through the tube-like structure of meteoroids left in the wake of a comet. Such meteoroid tubes, or as they are more commonly called meteoroid streams, are formed after a comet has made many repeated passages by the Sun. Meteoroid streams are composed of silicate (i.e. rocky) grains that were once embedded in the surface ices of a parent comet. Grains are rel…
If a meteoroid is to survive its passage through Earth's atmosphere to become a meteorite, it must be both large and dense. If these physical conditions are not met, it is more than likely that the meteoroid, as it ploughs through Earth's atmosphere, will either crumble into many small fragments, or it will be completely vaporized before it hits Earth's surface. Most of the me…
Even though many thousands of meteorites fall to Earth each year it is rare to hear of one hitting a human being. The chances of a human fatality resulting from the fall of a meteorite have been calculated as one death, somewhere in the world, every 52 years. Thankfully no human deaths from falling meteorites have been reported this century. A woman in Sylacauga, Alabama, was injured, however, by …
Citing this material
Please include a link to this page if you have found this material useful for research or writing a related article. Content on this website is from high-quality, licensed material originally published in print form. You can always be sure you're reading unbiased, factual, and accurate information.
Highlight the text below, right-click, and select “copy”. Paste the link into your website, email, or any other HTML document.
User Comments