On February 9, 1913 an extraordinary and unique phenomenon was observed by
multiple witnesses across Canada , the US and the island
of Bermuda . Known as the Great Meteor Procession, this event seems
to suggest that Earth once had, at least for a time, a second, small natural
satellite. Think about that, that would mean that up until 1913 Earth
technically had two natural moons.
Over a hundred reports exist
of this phenomenon and what they indicate is that between 40 and 60 very slow
moving fireballs arranged in groups moving in what appeared to be an identical
path crossed the sky over the course of several minutes. This would be unusual
for a normal meteorite, those tend to be lone wolves. It would be less unusual
for a meteor shower, though those tend to involve dust grains and the apparent
size of these fireballs would be more consistent with sizeable meteorites.
Meteor showers also tend to
be fairly predictable events. They happen at the same time each year as earth
passes through debris field left in the trail of comets that have crossed our
orbit at some point in the past. Meteor showers also exhibit something called a
radiant, this is a point in the sky where meteors, if you trace them backwards,
appear to originate.
Astronomer Clarence Chant
determined from the reports that The Great Meteor Procession did not have a
radiant, and instead seems to have followed a great circle trajectory. There
are thought to be two possible reasons for this. The parent object might have
encountered earth before, grazed the atmosphere at a shallow angle and skipped
back out into space. This is not unheard of, a rather large fireball was
witnessed doing just that over western North America
in 1972. Once back in space it might have broken up into pieces setting up for the
multiple fire balls observed when it encountered earth again and was drawn in.
The second possibility is
that whatever was the source for the meteors was formerly in orbit of earth.
Now, bodies in the solar system, including earth, can capture other objects
such as asteroids. Quite a few of the smaller moons in the outer solar system are
believed to be just that, captured asteroids. They can eventually end up in stable
orbits if the conditions are right, or they can orbit for a time in a decaying
orbit. The latter may have been what happened here.
But there's another
possibility and while it's sort of one of those old, dusty theories within
space science that not a lot of people remember it was at least intriguing at
the time. Astronomer John O'Keefe proposed that instead the material that made
up the fireballs was instead a remnant of a ring system Earth might have had at
one time, similar to Saturn.
This ring system would have
been produced by the action of lunar volcanos long ago when they were still
active, which relates to another theory of O'Keefe's that tektites, a group of
natural glasses that show clear evidence of once having flown aerodynamically
through the atmosphere, originated on the moon. His main evidence for this was
a curious lack of water in tektites, internally they are very dry for something
that originated on earth.
The theory was given serious
consideration by science at one time. However subsequent studies of tektites
have shown that they are most likely generated from earth rock melted during
crater-forming asteroid impacts. The evidence for this has accumulated and is
now pretty convincing but it doesn't really answer O'Keefe's ring theory.
Might the moon early in its
history have sprayed materials far enough out into space to form a planetary
ring system around earth? There really isn't much evidence for it
unfortunately, other than potentially the Great Meteor Procession. And with
that, no associated meteorites were ever found so we may never know the origins
of this event. But it's at least fun to imagine planet earth with a second tiny
moon, or even a ring long ago in the past.
Thanks for listening! I am
futurist and science fiction author John Michael Godier currently plugging my
second channel. It's dedicated to science fiction and the science behind it and
in a not-so-creative frenzy one night I named it John Michael Godier II, link
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