People often mistake Venus for a star. After the Moon, it is the brightest object in our night sky. The dense cloudy atmosphere of Venus hides its surface from even the most powerful telescope. Only radar can penetrate to map the planet's features. Until it became possible to determine the surface features-largely flat, volcanic plains-scientists could not tell how long the Venusian day was. The atmosphere would be deadly to humans. It is made up of a mixture of carbon dioxide and sulfuric acid that causes an extreme 1/ greenhouse effect," in which heat is trapped by the atmosphere. The ancients, however, saw only a beautifully bright planet, and so they named it after their goddess of love.