Venus

 by Nayan Walia and Katlin Luu

Background:

The Roman goddess of love and beauty is Venus. Our solar system’s second planet probably received this name because it was the brightest of the planets known to the ancients. Most features on the planets’ surface are named for female figures also.                   

Only a mere 108,209,000 kilometers away, Venus is the brightest and most radiant object in the night sky, apart from the moon, with an apparent magnitude of -4.6. Its bright glow is visible to the naked eye a few hours before sunrise and after sunset.

Known since prehistoric times, Venus was popularly, yet incorrectly, thought of as two separate objects: the morning star – Eosphorus – and the evening star – Hesperus, or sometimes referred to as Lucifer.

Similarities to Earth:

Due to many similarities, astronomers refer to Venus as Earth’s sister planet. Similar in size, mass, gravity, density, and volume, these two planets are believed to have formed at the same time also. They even formed out of the same nebula. But the similarities stop here. Unlike Earth, Venus has neither oceans nor any moons.

Venus is only slightly smaller than Earth, with 95% of Earth’s diameter and 80% of Earth’s mass. Both show a few craters, suggesting relatively young surfaces. Both have alike densities and chemical compositions, as well. These Earth-like features were the reason early astronomers thought Venus might hold life. Unfortunately, because of the severe temperatures of the planet, our sister planet may be the most unhabitable place in our solar system.

Rotation and Orbit:

The sixth largest planet, Venus, has an orbit that is most nearly circular – better than any other planet– and it only has an eccentricity of less than 1%. Unlike most other planets, Venus rotates from east to west, or clockwise. A theory states that solar tides could have slowly resulted in this backward rotation. Another odd fact is that a Venusian day is 243.01 Earth days — longer than it’s own year of 224.7 days!

Extraordinarily, the rotation of Venus and its orbit are synchronized in such a way that observers from Earth would only see one face of the planet, when they are at their closest to each other.   

Atmosphere:

The heavy atmosphere that surrounds this terrestrial planet is composed mostly of carbon dioxide with almost no water vapor or ozone layer. Small percentages of nitrogen, sulfuric acid, water vapor, hydrofluoric acid have also been found. Several layers of kilometer-thick clouds encircle Venus, completely obscuring our view of the Venusian surface. These clouds are composed of sulfuric acid. Not surprisingly, the atmospheric pressure is approximately 90 times that of Earth’s at sea-level.

Climate:

With a scorching surface temperature of 482 C or 900 F, Venus is actually hotter than Mercury. This is due to a runaway greenhouse effect, which is the result of the heavy atmosphere of carbon dioxide. The sunlight that passes through the clouds and atmosphere heats the surface; the heat is trapped by the thick atmosphere and unable to escape.

Strong winds up to 350 kmph rage at the top of the clouds, but on the surface they are very slow, no more than a few kmph. Aside from these winds, Venus is popular for its very, very dry crust.

Surface:

The hot, dry surface of Venus has rolling plains, mountains, highland regions, rift valleys, and a few craters.

A lot of the minerals that are found that happen to be basalts, which are covered by a thin metallic layer. However, the thing that captures most astronomers’ hearts about Venus’ surface is the volcanoes.         

Venus is littered with large shield volcanoes, which are still active, though only in a few hot spots. The rest of the places have been silent for a few hundred million years. Now, Venus is covered by lava flows from those volcanoes. These flows appear as smooth, low rolling plains. There are a chain of 167 volcanoes. All of the eruptions are what changed the surface of Venus. The coronae, the circular rings and bulges, signal volcanism. These characteristics tell us that the planet is changing; volcanism gives Venus new layers.

There are also faults and fractures in the crust, yet no plate tectonics. Convention currents are also helping to shape the surface by creating mountains.

There are two large highland areas on Venus: Ishtar Terra, located in the northern hemisphere and about the size of Australia, and Aphrodite Terra, located along the equator and about the size of South Africa. Most of Ishtar Terra consists of Lakshmi Planum, a high plateau surrounded by the highest mountains on Venus.

No small meteoroids have hit Venus. They burn up in Venus’ dense atmosphere before reaching the surface. Only groups or bunches of craters appear on the surface; this indicates that large meteoroids usually break up in the atmosphere.

It is widely believed that Venus was once a host to a large amount of water, like Earth, but it was boiled away due to its close proximity to the sun. Astronomers are extremely eager to find out more about our sister planet, and why it turned out so differently, in hopes of learning more about our own home.

Interior:

Venus has a core, mantle and crust. Very similar interior to the Earth, Venus has a iron core is probably around 3000 km in radius and a molten rocky mantle. The core is thought to be partially liquid. Also like Earth, stress on the surface occurs, due to convention in the mantle. The smaller size of the planet suggests lower pressures in its deep interior. The lack of plate tectonics is most likely due to the dry surface and mantle. This results in the prevention of heat loss, leading to lack of its cooling, which, in turn, is why there is not a strong magnetic field. 

Odds and Ends:

Venus has no magnetic field. Though the reason for this is unknown, one hypothesis is that this is caused by its slow rotation.

Venus does not have any satellites, therefore it produces a tale.

In June of 2004, Venus passed directly between the Earth and the Sun; this is called the "Transit of Venus". It appeared as a large black dot on the sun’s disk. This transit is quite rare, last occurring 1882. Luckily for the present generations, the next "Transit of Venus" will happen in 2012, but after that, you’ll have to sit tight until 2117.   

Recent Discoveries:

Only in the recent decades have astronomers been able to get a closer look at Venus. Over 20 spacecrafts have visited our sister planet since 1962. Some dozen have also landed on the surface. Radar images are the roots for the majority of what we know today about the surface features of Venus.  

Proposed Experiments

                          Minerals' Composition

Required Experiments and Methods to carry it out: