They did not travel blindly outward, for that would have been both a crude waste of power and inaccurate. Instead, the ship drove at a long slant from the Sun, moving in a gently curving orbit that would bring it onto Venus at the same time that Venus itself was moving along in its orbit. This is what they had tried to do before, but without success. Venus travels around the Sun at a speed of about 32 miles per second, and takes about 224.5 days to complete the circuit. From where the _Magellan_ took off, it would approach and overtake Venus at a speed a little greater than the 32 miles per second. The days passed swiftly enough. They had developed the pictures taken in the Mercury station, and the engineers and astronomers spent long hours debating their features, matching up what they had seen with what was known about the Andes station. The shining face of Venus grew larger. It was a mysterious planet, the most mysterious in the system, even though it was the closest of the planets to Earth. Venus was a world whose atmosphere--of Earthly depth--was a solid mass of clouds. Never had the clouds lifted to reveal the surface. The clouds reflected the sunlight brilliantly, yet as Burl could now see with the naked eye, parts of it were hazy, as if mighty storms were raising dark particles from below. "We've had a couple of prober rockets shot into its surface," said Russ, as they watched the oncoming planet. "They didn't prove much--faded out fast, but we think they established its length of day. Nobody knew how many hours it took Venus to rotate on its axis. Some even thought it always presented one face to the Sun as does Mercury. Others thought it had a quick day, shorter than Earth's. Others gave it a day almost a month long. "Our prober rockets, carrying unmanned instruments, rather definitely indicate that the planet has a day about twenty Earth-days long. Even though it's shielded by the clouds, it must be miserably hot near the surface." "We'll soon find out." Burl grinned. "After Mercury, it couldn't be so bad. Maybe it rains all the time." Russ shrugged. "Who knows?" he said. Venus was a vast sea of swirling white and gray clouds beneath them when the _Magellan_ reached it. They hung above the cloud level, while stretching below them lay the circular bowl of veiled mystery that was the fabled evening star of poem and song. Oberfield was probing the surface with the radiation counters for the Sun-tap distortion. None had been detected from Earth, but observation of the sunny face of Venus had always been difficult from the third planetary orbit. But quickly the dour astronomer proved the fact. A calculation of the planet's albedo--its rate of reflected sunlight--showed that in one large central section there was a dimming out. Somewhere in that spot, the light was being diverted.