This image shows an oxygen trail created when a small comet was disrupted as it approached our planet on September 15, 1996. This image was taken by the Polar spacecraft's Earth Camera in ultraviolet wavelengths. The oxygen trail has been superposed upon a "Face of the Earth" map of our planet.
Courtesy of Dr. Louis A. Frank, The University of Iowa and NASA

Small Comets

In 1997, we wrote that snowballs from space may be hitting the Earth! We were recently alerted that those snowballs may have been identified! Here's the scoop!

These snowballs may be really small comets. They are millions of times smaller than comets like Halley's or Linear.

Scientists think that the comets are made mostly of water...that's why they were originally called snowballs! But, don't worry about getting hit by one of these snowballs! Even though one small comet probably hits the Earth's atmosphere every three seconds, they are not dangerous to humans or animals, because they break up in the atmosphere.

Scientists want to take measurements from close-up. So, the next step is to send a spacecraft to see the small comets up close! That will help us to know whether or not this snowball hypothesis is correct! (Remember, theories have to be proven over and over again for them to be considered true!)

Some scientists do not believe in the small comets hypothesis. They think that there must be some other explanation of the data. Scientists are still having a debate about the small comets idea. Some say it is true, but others think it is false. We still don't know for sure!

Last modified October 2, 2006 by Randy Russell.

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