పుట:The Solar System - Six Lectures - Lowell.djvu/29

ఈ పుట ఆమోదించబడ్డది


  Our Solar System 11

what that nebulous mass was to begin with; for in their subsequent history there has been nothing to make them what they are. They cannot have come from our present sun, since it became a sun, as their orbits conclusively show. They must have come from the sun our system had before the catastrophe, which caused the nebula which caused our Sun, occurred. They antedate the creation of the nebula itself which our nebular hypothesis posits as the beginning of things. They are old with an age which staggers imagination; older in cycles of evolution, if not in years, than anything we see in the countless spangles of a winter's night in the blue-black firmament of sky. Before the silent tale they tell, history shrinks into yesterday, the Earth's career into the day before, and the evolving of the solar system itself into modernity. Through that strange Widmannstättian fretwork that marks their surface like the lacing of frost-work on a window-pane, we seem to be gazing past the iron bars into the immensity, not of space alone, but of eternity.

Next to meteors, and doubtless close to themShooting-stars. in kind, come shooting-stars. Superficial distinctions have caused them to be classed apart, but in all likelihood size alone separates the two.

In the case of shooting-stars, we have the flash,