Geek Fix: Green comet zooming our way

A comet is streaking back our way after 50,000 years. The dirty snowball last visited during Neanderthal times, according to NASA. It will come within 26 million miles (42 million kilometers) of Earth Wednesday before speeding away again, unlikely to return for millions of years. So do look up, contrary to the title of the killer-comet movie "Don't Look Up."