Over the course of a night, it will be noticed that more sporadic meteors can be seen in the hours before sunrise than in the hours after sunset. Perhaps the most important factors necessary in order to observe meteors are to have a clear, unobstructed view, out in the open, and under as dark sky conditions as possible. The number of random, or “sporadic” meteors that can be seen in the night sky is quite variable, depending upon such factors as the time of night, time of year, light pollution, and cloud conditions. How many meteors can I expect to see if I go out to observe for them when no meteor shower is occurring? On the morning side, or leading edge of the earth, meteoroids can collide head-on with the atmosphere and tend to be fast.īack to top 4. On the evening side, or trailing edge of the Earth, meteoroids must catch up to the earth’s atmosphere to cause a meteor, and tend to be slow. The wide range in meteoroid speeds is caused partly by the fact that the Earth itself is traveling at about 30 km/sec (67,000 mph) as it revolves around the sun. This column, or meteor trail, is usually less than 1 meter in diameter, but will be tens of kilometers long. When the meteoroid collides with air molecules, its high level of kinetic energy rapidly ionizes and excites a long, thin column of atmospheric atoms along the meteoroid’s path, creating a flash of light visible from the ground below. Meteors enter the atmosphere at speeds ranging from 11 km/sec (25,000 mph), to 72 km/sec (160,000 mph!). Those of asteroid origin can be composed of dense stony or metallic material (the minority) while those of cometary origin (the majority) have low densities and are composed of a “fluffy” conglomerate of material, frequently called a “dustball.” The brilliant flash of light from a meteor is not caused so much by the meteoroid’s mass, but by its high level of kinetic energy as it collides with the atmosphere. The majority of visible meteors are caused by particles ranging in size from about that of a small pebble down to a grain of sand, and generally weigh less than 1-2 grams. How big are most meteoroids? How fast do they travel? This is a general guideline only, since very fast meteors may first become visible above this height, and slow, bright meteors may penetrate below this band.īack to top 3. This “meteoric region” lies between about 80 km and 120 km (50 to 75 miles) in altitude. Most meteors occur in the region of the atmosphere called the thermosphere. If remnants of the parent meteoroid survive the trip through the atmosphere to reach the ground, then these remnants are called meteorites.īack to top 2. It was not until the mid-1800’s that the extra-terrestrial nature of meteors was widely recognized. Meteors were once thought to be a purely atmospheric phenomena, and the study of these and other atmospheric effects, especially weather, spawned the science of meteorology. Whenever a meteoroid plows into the Earth’s atmosphere, it will create a brief flash of moving light in the sky, called a meteor. Meteoroids are the smallest members of the solar system, ranging in size from large fragments of asteroids or comets, to extremely small micrometeoroids. What is the difference between a meteor, a meteorite, and a meteoroid?ĭownload a printable version of this poster for FREE. If you need further clarification or have further questions, please feel free to contact us via electronic mail. Where can I find information on historical meteor observations?īelow are some relatively concise answers to the above questions.
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