Green Comet Machholz -- Friend, Not Foe
"Perhaps it's a comet." Still frowning, Bob Star swung back toward the observatory. "It looked like one - it was a short streak of that queer, misty green, instead of the point a star would show..."
Inside the chilly gloom of the observatory, Bob sat down at the telescope. Its mechanisms whirred softly, in swift response to his touch. The great barrel swung to search space with its photoelectric eyes, and the pale beam of the projector flashed across to the concave screen.
...He stepped up the electronic magnification. Vindemiatrix and the fainter stars slipped out of the field. The comet hung alone, and swiftly grew. Its shape was puzzling - a strangely perfect ellipsoid. A greenish football, he thought, kicked at the System out of the night of space - by what?
...Using ray filters and spectroscope, with the full power of the circuits, he strove to pierce that dull green veil, and failed."
As it happens, you have the opportunity to step out your door in the coming weeks, and observe a comet described by NASA as "glowing alien green" yourself. Here's how to see Comet Machholz in early January:
Look 2 degrees to the right of the Pleiades. (If you live in the southern hemisphere, look to the left.) The tip of your pinky finger, held at arms length is about 1 degree wide, so 2 degrees is two pinkies. The cloud resembles a faint and fuzzy star, barely visible to the unaided eye, but easy to see through binoculars.
With a diameter of at least 450,000 kilometers, the coma of this comet is at least three times wider than the planet Jupiter. Named after its discoverer, amateur Don Machholz, astronomers have been watching it since last August. This week is its closest approach - about 52 million kilometers. The cometary body itself is small; its two tails (the ion tail points up; the dust tail points down in the picture below) are what give it size. The comet glows green because its coma contains cyanogen and diatomic carbon, both of which glow green when illuminated by sunlight.
And the peculiar ellipsoid shape seen in the novel? Twelve million miles long, it was a ship; its green surface was an impenetrable force barrier. Its masters were beings of light and mist. You'll need to read the novel to see what it contained, but here's a hint; the paths of the bodies in our solar system are ellipsoidal.
(This Science Fiction in the News story used with permission from Technovelgy.com - where science meets fiction.)
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