Although it's a long shot, Grinspoon said, there is a plausible argument for Venusian life — not on the planet's superheated surface, but in the clouds. Some 30 miles up, there should be a habitable niche where pressure and temperature are earthlike. For energy, floating creatures resembling bacteria could use ample sunshine or chemicals in the clouds; of course, these beings would have to tolerate sulfuric acid, but so-called extremophiles on Earth have shown that life can thrive in even the harshest environments.
A factor of 200 is not enough to account for the dryness of Venus. The rate of escape of water from Venus must be about 106 times greater than on Earth, in order to remove the water as rapidly as it is released from the interior
of the planet. However, this still larger escape rate might be realized if the shielding layer of oxygen were missing from the Venus upper atmosphere.
As a result of a loss of water, the geological evolution of the surface of Venus slowed right down because it was unable to develop plate tectonics like the Earth. Biological evolution was prevented altogether. Thus, in terms of Venus being another Earth in climate and habitability terms, it evolved too quickly at first, then too slowly.
Researchers using data from the European Space Agency’s Venus Express spacecraft said they spotted three active volcanoes that recently poured red hot lava onto the planet’s already broiling surface. The discovery, announced in a paper published Friday online in Science, suggests that Venus – like the Earth – is periodically resurfaced by lava flows, explaining why it seems devoid of craters.
About 65 percent of Venus is covered by flat plains, it also has mountains, canyons and valleys. There are thousands of volcanoes on Venus, some up to 150 miles (240km) in diameter. Venus also has ring-like structures called coronae which do not exist on Earth.
Veiled by dense cloud cover, Venus, our nearest planetary neighbor, was the first planet to be explored. The Mariner 2 spacecraft, launched on August 27, 1962, was the first of more than a dozen successful American and Soviet missions to study the mysterious planet. As spacecraft flew by or orbited Venus, plunged into the atmosphere or gently landed on Venus' surface, romantic myths and speculations about our neighbor were laid to rest.
Venus is a planet with ongoing geological processes – a recently active surface and recycling atmosphere. Unlike all other planets of the inner solar system, it's not dead yet. This makes Venus a great foil for learning about Earth.
Venus is almost exactly the same size as Earth, and its orbit is closer to our planet than that of any other planet in the solar system. Venus is entirely surrounded by a thick, opaque layer of clouds, so that all we can see from Earth is the top of this cloud cover. Earth and the rest of the planets in the solar system rotate from west to east (counterclockwise, as seen from above the north poles), but Venus spins from east to west, or clockwise.
Galileo pointed his telescope at Venus in 1610, and confirmed Copernicus’ theory by showing that Venus went through distinct phases, just like the Moon. The phases matched the predictions made by Copernicus, and demonstrated that Venus was really a planet, orbiting the Sun and not the Earth. This model was confirmed even more when Venus made a transit across the surface of the Sun on December 4, 1639; the most recent transit of Venus happened in 2004, and the next one will occur in 2012.
Venus has been known as the brightest object in the night sky since the beginning of recorded history. On clear nights, Venus is the first object to appear and is sometimes so luminous that its light casts very faint shadows on the ground on Earth. It has figured prominently in the mythologies of many cultures, including those of the Sumerians, Aztecs, Maya, and ancient Romans – the Romans named the planet Venus, after their goddess of love and beauty.