2

Why don't comets zoom across the sky?

Before answering this question, think about this: Have you ever seen the Moon whiz across your line of sight like a meteor? Even though the Moon is traveling around the Earth at more than 2,000 mph (3,200 kilometers per hour), at its average distance of 239,000 miles (382,000 kilometers) from Earth, its orbital motion is barely perceptible.

Similarly, although a bright naked-eye comet might be moving at many tens of thousands of miles per hour through the inner solar system, its distance from Earth typically will measure in tens of millions of miles. So while a bright comet will indeed appear to move, because of its distance from Earth, its apparent night-to-night movement against the background stars is very slow.

A comet moves across the sky in the fashion of the Moon (or the planets for that matter). Not in the fashion of a streaking meteor. [See the best comet images ever]

Next Page: If you can't take the heat, change hemispheres