Earth - Sun Measurement Name: Marcelo Status: student Age: 20s Location: N/A Country: N/A Date: 1999 - 2000 Question: 1)Is the distance from the earth to the sun measure in light years or miles? 2)How many miles or light years are there between the earth and the sun? Replies: You can measure it in any unit of length. You could measure it in millimeters if you wanted. The distance between the earth and the sun is not constant. The earth's orbit around the sun is nearly circular, but not perfectly so. The earth is actually closest to the Sun in the northern hemisphere winter. I'm not certain of the time of closest approach, though. On average, the distance between the earth and the sun is 93 million miles. This is not anywhere near a light-year. It is more like 8.3 light-minutes. Richard Barrans Jr., Ph.D. The distance between the earth and the sun is 93,000,000 miles. The time it takes light to travel this distance is 93,000,000 miles/186,000 miles/sec or 500 seconds. Hence the time is 500sec/60 or 8.333 minutes. What fraction of a year is 8.333 minutes, well that is 8.333/(60x24x365) = or 0.00001585 light years. You can express the distance either way, but in this case 93 million miles makes more sense. H. Myron Marcelo, We measure the distance in miles, 93 million or so to be exact. A light year is defined as the distance light can travel in one year. Lights moves at the speed of 186,000 miles per second. Therefore, light from the sun does not take a year to reach us, since it is, by comparison with other starts, relatively close to us . If you consider light from the sun must travel 93,000,000 miles and is moving at 186,000 miles per second, the light takes only about 8.3 minutes to reach us. Light years as a measurement of distance is most useful when we are discussing extremely distant galaxies, etc.. Using 186,000 miles per second as the speed of light, we find it can travel 5865696000000 miles in one (average) year. The sun, in light years, is only 0.00001585 light years away, so miles is a better unit to use. Thanks for using NEWTON! Dr. Rupnik 93 million miles 8 light minutes (.25 millionths of a light year) Tim Mooney Click here to return to the Astronomy Archives

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