re: Japanese probe Akatsuki's pictures of Venus

Venus

Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.[12] It has the longest rotation period (243 days) of any planet in the Solar System and rotates in the opposite direction to most other planets. It has no natural satellites. It is named after the Roman goddess of love and beauty. It is the second-brightest natural object in the night sky after the Moon, reaching an apparent magnitude of -4.6 – bright enough to cast shadows at night and, rarely, visible to the naked eye in broad daylight.[13][14] Orbiting within Earth's orbit, Venus is an inferior planet and never appears to venture far from the Sun; its maximum angular distance from the Sun (elongation) is 47.8


Size comparison with Earth:



Venus is one of the four terrestrial planets in the Solar System, meaning that it is a rocky body like Earth. It is similar to Earth in size and mass, and is often described as Earth's "sister" or "twin".[20] The diameter of Venus is 12,103.6 km (7,520.8 mi)—only 638.4 km (396.7 mi) less than Earth's—and its mass is 81.5% of Earth's. Conditions on the Venusian surface differ radically from those on Earth because its dense atmosphere is 96.5% carbon dioxide, with most of the remaining 3.5% being nitrogen.[21]


Global radar view of Venus (without the clouds) from Magellan between 1990 and 1994: