Tonight at dusk, Venus, Castor, and Pollux will form an almost perfect straight line in the Western sky at dusk. To see the show, head out after the sky starts to dim and look West. Venus, third brightest object in the sky only behind the Sun and Moon, will be impossible to miss. As for Pollux and Castor, they're a pair of bright stars and as well as alpha and beta stars of the zodiac constellation Gemini. If the fact that the line is just about straight weren't unique enough, The stars and planets are all separated by about the same angular measurement, too.