The Venusian surface The surface of Venus, shrouded by a thick atmosphere, remained unseen until radar technology came to study the nearest planet. Under the layers of clouds, there is rocky earth. However, unlike Mars and Mercury, which both have cratered surfaces, Venus has a comparatively smooth surface. This may be because it used to be like Earth, but now it's just hellishly hot.
Venus was once like Earth. With clouds and water vapor streaming across its surface, it was more like Earth two years after it formed. But then something strange happened: The sun began to shine more intensely than today, heating up Venus' atmosphere like an oven. This heat flow is still responsible for most of the planet's current condition. It destroyed much of what was alive on Venus and also melted its crust, pouring that liquid rock down into its deep interior.
The pressure inside Venus' atmosphere is about 90 times greater than that at sea level on Earth. This is why all the features on Venus' surface are shaped by extreme pressure and not by gravity as on Earth or other planets. There are no mountains on Venus because there isn't time for them to form. If Venus' ocean had been able to sustain itself for another 600 million years, then mountains might have appeared.
But even though it's a dead planet, there is life on Venus. Microorganisms live in the hot waters of Venus' ocean and also on its shorelines.
The Venusian surface Under the layers of clouds, there is rocky earth. While planets like Venus were developing early in the solar system's existence, the cloud of dust and debris surrounding the sun was a tumultuous environment. Much of this material may have settled into Earth-like orbits, but some of it was blown out into space.
This explains why Earth and Venus share so many similarities: they are both terrestrial worlds with atmospheres made of carbon dioxide. They also have similar sizes and masses. But the fact that Venus is more similar to Earth than any other planet in our solar system shows how important it was that Earth escaped contamination by planetary materials. If Venus had been less kind to its development, we would be living under a thick layer of rock instead of air.
It also means that if humans are ever going to live on another world, we need to understand how to protect ourselves from harmful elements in the environment. For example, if oxygen is lacking or too scarce in an atmosphere, then life as we know it could not exist. On Venus today, the pressure is about 90 times greater than at sea level on Earth. It is believed that even before its entire surface was transformed into water, Earth's earliest oceans covered all but the most extreme environments. These conditions would have killed off any life that emerged within the first few million years after the planet formed.
Student Characteristics The planet is somewhat smaller than Earth and, on the interior, is comparable to Earth. We can't see the surface of Venus from Earth because it's obscured by heavy clouds. However, satellite flights to Venus have revealed that the planet's surface is dotted with craters, volcanoes, mountains, and vast lava plains. It also has a dense atmosphere made of carbon dioxide.
Venus was once like Earth's sister planet, but then something terrible happened to Venus. Earth wasn't alone in its solar system! Another planet called Venus wandered too close to the Sun and got burned. Today, Venus is nothing more than a hot, desolate rock with extremely high levels of atmospheric pressure.
Physical Characteristics The planet has an average diameter of 740 miles (1,200 km), which makes it about 75 percent larger than Earth's diameter. It has a mass about 5 times that of Earth's; however, due to its large distance from the Sun, it is only half as luminous.
Most of Venus' surface is covered by thick layers of volcanic rocks formed when molten material spewed out from deep within the planet's body. There are no continents or oceans on Venus. Although it has a faint hue, much of this rock is dark gray or black. Other areas of Venus have been exposed to intense heat and pressure over time, causing them to brighten up brightly enough for us to see from afar.