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Science Frontiers ONLINE No. 47: Sep-Oct 1986 |
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Oceans from outer space?
Back in SF#44, we related how L.A. Frank, at the University of Iowa, had detected dark spots on satellite images of the earth's dayglow. Frank thought that the spots might be due to clouds of water vapor released as small, icy comets hit the atmosphere. P. Huyghe has recently written more about Frank's discovery, his theory, and its reception by the scientific community.
"These comets are not occasional visitors, he [Frank] says, like the one that comes by every 76 years and -- lucky for us -- never actually drops in. No, these are very small, cometlike objects that enter our atmosphere at a rate of 20 per minute, he says. These comets, which he believes must contain about 100 tons of water apiece, vaporize on impact with the atmosphere and fall as rain or snow. Now that may seem like one sizeable cold shower, but on a yearly basis he says it's actually only a tiny fraction of the annual preciptation. Then again, over a span of 4.5 billion years, which is about how old the earth is, that's enough water, he says -- trumpets blaring -- to create the oceans."
Naturally, such a theory is very disturbing because it runs counter to the widely accepted idea that the oceans were created by the outgassing of water vapor from the newly accreted earth. As a consequence, Frank's data are readily accepted, but his explanation of them is not.
"That's as crazy as they come." (A noted astronomer)"...a case of Halley's fever." (One geologist)
"...his interpretation is preposterous." (Fred Whipple)
Critical as other scientists may be of Frank's theory, they have no other explanation for the dark spots on the earth's dayglow images. Furthermore, scientists are far from united about how the earth's oceans really did form.
As serendipity would have it, Frank's theory connects in an interesting fashion with the origin-of-life speculations in this issue. Frank remarks, in connection with organic sludge in comets:
"These objects, because they are like a piston of gas, can bring organic material down without burning it up like a meteor does."
(Huyghe, Patrick; "Origin of the Ocean," Oceans, 19:8, August 1986.)