Venus is covered with thick clouds that create a greenhouse effect that makes it very hot.
Venus has no moons.

• Diameter: 12,100 km. It is about 1040km smaller in diameter than Earth
• Temperature: Ranges from 900F+/- 50F (about 500°C +/- 32°C) at the surface
• Distance from Earth: At its closest, Venus is 41,840,000 km away* Atmosphere: Carbon dioxide (95%), nitrogen, sulfuric acid, and traces of other elements
• Surface: A rocky, dusty, waterless expanse of mountains, canyons, and plains, with a 200-mile river of hardened lava
• Rotation of its axis: 243 Earth days (1 Venusian Day)
• Rotation around the Sun: 225 Earth days
• Magnetic Field: No

Venus is the brightest object in the sky besides our Sun and the Moon. It is also known as the morning star because at sunrise it appears in the east and and evening star as it appears at sunset when it is in the west. It cannot be seen in the middle of the night.

A Venusian day is 243 Earth days and is longer than its year of 225 days. Oddly, Venus rotates from east to west (retrograde – opposite to that of earth). If you were on Venus, the Sun would rise in the west and set in the east.

Venus and Earth are close together in space and similar in size, which is the reason Venus is called Earth’s sister planet.

Mercury is the closest planet to the Sun and the smallest planet in the(0.055 Earth masses). Mercury has no natural satellites, and its only known geological features besides impact craters are lobed ridges or rupes, probably produced by a period of contraction early in its history. Mercury’s almost negligible atmosphere consists of atoms blasted off its surface by the solar wind. Its relatively large iron core and thin mantle have not yet been adequately explained. Hypotheses include that its outer layers were stripped off by a giant impact, and that it was prevented from fully accreting by the young Sun’s energy.

Mercury is bright when viewed from Earth, ranging from -2.0 to 5.5 in apparent magnitude, but is not easily seen as its greatest angular separation from the Sun (greatest elongation) is only 28.3°: It can only be seen in morning and evening twilight. Comparatively little is known about it; the first of two spacecraft to approach Mercury was Mariner 10 from 1974 to 1975, which mapped only about 45% of the planet’s surface.

The second was the MESSENGER spacecraft, which mapped another 30% of the planet during its flyby of January 14, 2008. MESSENGER will make two more passes by Mercury, followed by orbital insertion in 2011, and will survey and map the entire planet.
Physically, Mercury is similar in appearance to the Moon. It is heavily cratered, has no natural satellites and no substantial atmosphere. It has a large iron core, which generates a magnetic field about 1% as strong as that of the Earth. It is an exceptionally dense planet due to the large size of its core. The surface temperatures on Mercury range from about 90 to 700 K (-180 to 430 °C), with the subsolar point being the hottest and the bottoms of craters near the poles being the coldest.
Recorded observations of Mercury date back to the Sumerians in the third millennium BC. Before the 4th century BC, Greek astronomers believed the planet to be two separate objects: one visible only at sunrise, which they called Apollo; the other visible only at sunset, which they called Hermes. Our name for the planet comes from the Romans, who named it after the Roman god Mercury, which they equated with the Greek Hermes. The astronomical symbol for Mercury is a stylized version of Hermes’ caduceus.

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