Democratic Sentinel, Volume 9, Number 50, Rensselaer, Jasper County, 15 January 1886 — Cause and Nature of Meteors. [ARTICLE]

Cause and Nature of Meteors.

It is now known that meteors can not originate on the moon, or within the regions of the earth's atmosphere. It is also universally conceded by all observers of natural phenomena that innumerable minute bodies fill celestial spaces, moving around the sun in every possible kind of orbit. Of the exact nature of these small bodies comparatively little can be known, but it is certain that our earth is continually encountering them in its passage through its orbit. They are burned in passing through the upper regions of our atmosphere, and the shooting-star is simply the light of that burning. The question how they can be burned so quickly and with so intense a light puzzled astronomers until it was seen that these phenomena could be fully accounted for by the mechanical theory of heat. It is now established that heat is only a certain form of motion; that hot air differs from cold air only in a more rapid vibration of its molecules, and that it communicates its heat to other bodies simply by striking them with its molecules, and thus setting their molecules in vibration. An exact measure has been found for this increase of heat, a velocity of 1‘25 feet per second being shown to increase the temperature one degree, and higher velocities increasing temperature in proportion to the square of the velocity, as 4 degrees with a velocity of 250 feet, 10 degrees with one of 500 feet second, and so on. To find the‘heat to which a meteor is exposed in moving through our atmosphere we divide its velocity in feet per second by 125; the square of the quotient will give the temperature in degrees. Now, the earth moves in its orbit at the rate of Ob,ooo feet per second, and if it met a meteor at rest this velocity would create a rise in temperature corresponding to about 600,000 degrees, which largely exceeds any temperature that can be created on the earth, even by artificial means. If, as is commonly the case, the meteor is also moving to meet the earth, the increase of temperature will be even greater. It can not be said that the meteors are actually heated up to this temperature, but the air acts upon them as if it .were heated to,, this point; thatsis, it burns them instantaneously with* an enormous evolution' of light and that, just as a furnace would if heated to a temperature of several thousand degrees. Nor are the light and heat of ordinary burning even mentionable in comparison with the fusing temperature, the intense blaze which such heat would create in the hardest, most non-cumbusfible substance in nature. Now, if the meteor is so small and fusible that the heat can act upon it instantaneously, it is all dissipated in the upper regions of the atmosphere, and we have simply a shooting star or brilliant meteor. But sometimes these b -dies are so large and j firm that the he at has not time to penI etrate into their interior, but spends ! itself melting and volatilizing the outer portions; the body then passes throne h j the atmosphere and falls upon the | earth as an aerolite, or meteoric stone. | Sometimes when the body strikes the | denser part of our atmosphere, the resistance is so great that the aerolite is broken to pieces with great violence, | causing a tremendous detonation. This is usually spoken of as an explosion, | but there is a good reason to believe that the loud sound and b rsting of the stone are both due to its strik ng the rapidly moving air with an eno?- . mous velocity of its own,— lnter 1 Ocean.