The Second Planet in Our Solar System. Venus. By Dorothy.Yang Lucy.Xiao

Transcription

1 The Second Planet in Our Solar System Venus By Dorothy.Yang Lucy.Xiao

2 venus Basic information about Venus.length of year.length of day.temperature.density.chemical composition of the atmosphere.chemical composition of the solid portion of the planet

3 venus length of year The length of year on Venus is days. In other words, Venus only takes 62% of the time Earth takes to complete an orbit around the Sun. But one of the strangest things about Venus is that it s actually rotating backwards on its axis compared to the other planets in the Solar System. And even stranger, a day on Venus is actually longer than a year on Venus. A day on Venus lasts 243 Earth days. And this is longer than the days it takes to orbit the Sun. If you could stand on the surface of Venus and actually see the Sun, you would see it rise in West, cross the sky in about 117 days and then set in the East. Compare the Venus length of year to Mercury and Earth. Mercury only takes 88 days to orbit the Sun, while Earth takes days to go around the Sun.

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5 venus length of day The length of day on Venus is 243 Earth days. Read that again, it s not a year, but the length of a single day. In fact, a year on Venus is only days, so a day on Venus is longer than its year. And things get even stranger. Venus rotates backwards. All of the planets in the Solar System rotate counter-clockwise when you look at them from above. But Venus turns clockwise. Of course it s impossible to stand on the surface of Venus and survive. And even if you could, you wouldn t be able to see the Sun through the dense clouds. But if you could stand on Venus and see the Sun, you d see the Sun rise in the West, pass through the sky for days and then set in the East. That s the opposite of what we see here on Earth. Why does Venus rotate backwards? Astronomers aren t sure, but it s possible that Venus suffered a massive impact from a large planetoid billions of years ago. This could have given the planet a kick that set it slowly tumbling, eventually flipping completely over so that it s now upside-down.

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7 venus temperature Venus is the second closest planet to our Sun, and is the hottest planet in the solar system. The blistering temperature on Venus is due in part to the oppressive atmosphere that is 100 times heavier than that of Earth. The greenhouse gasses that smother the planet create a uniform and constant temperature on all sides of Venus.

8 venus temperature But on Venus, the surface temperature is 460 degrees Celsius, day or night, at the poles or at the equator. Beyond its thick atmosphere, Venus axial tilt (aka. obliquity) plays a role in this temperature consistency.

9 venus density The density of Venus is grams per cubic centimeter. Need some kind of comparison? The density of Earth is g/cm3. So Venus is definitely less dense than Earth. And it s even less dense than Mercury. Of course, it s much more dense than any of the outer planets, like Jupiter or Saturn.

10 venus density Scientists think that Venus has an interior structure similar to Earth, with a metal core, rocky mantle, and an outer crust. But these assumptions come purely from the density calculations. Here on Earth, scientists study the interior structure of the planet by using seismographs, and studying how seismic waves from earthquakes travel through the Earth. Since the surface of Venus is hot enough to melt lead, there s no way to leave scientific equipment on the surface for any period of time to study the interior of the planet. With its lower density, Venus has a lower mass than Earth. In fact, the mass of Venus is only about 81% the mass of Earth. And it s also a little smaller than Earth. This means that the surface gravity of Venus is only 90% of what you would experience on Earth

11 venus chemical composition of the atmosphere Earth and Venus share many physical characteristics. Atmosphere is not one of them. The atmosphere of Venus is so harsh that it is the main reason that no one has ever been able to make optical observations of anything other than the planet s upper atmosphere. Visualization of the planet is made impossible be the high amounts of sulfuric acid in the atmosphere. Clouds in the upper atmosphere are full of sulfuric acid droplets. Sulfur is highly reflective of visible light, thus preventing observation much deeper than the upper limits of the clouds themselves.

12 venus chemical composition of the atmosphere The next challenge that the atmosphere of Venus presents is its composition. It is made up of 96% carbon dioxide. Oxygen can not be detected even as a trace element. At the surface the atmospheric pressure is 92 times that of Earth. If you were able to find a way to survive the intense pressure and had enough oxygen, you would be standing on a surface that is hot enough to melt lead. The temperature across Venus, from pole to pole, is a steady 462 C as a result of the atmosphere s greenhouse qualities. In the hottest parts of the hottest deserts here on Earth, the temperatures never top 50 C. The sweltering surface of the planet is covered by volcanoes, impact craters, and old lava flows. There are 1,000 volcanic craters and crater remnants that are over 20 km in diameter. The surface has never been impacted by a small meteorite. The atmosphere burns up anything small. It could take an asteroid in excess of 50 km to survive long enough to hit the surface and then it would have lost close to half of its mass in the atmosphere. The entire planet was resurfaced by volcanic flows between 300 and 500 million years ago

13 venus chemical composition of the solid portion of the planet Venus is often referred to as Earth s twin planet (evil twin planet is more like it, when you consider the scorching temperatures). It s almost the same size, mass, gravity and overall composition. The composition of Venus is pretty similar to Earth, with a core of metal, a mantle of liquid rock, and an outer crust of solid rock. Unfortunately, scientists have no direct knowledge about Venus composition. Here on Earth, scientists use seismometers to study how seismic waves from earthquakes propagate through the planet. How these waves bounce and turn inside the Earth tell scientists about its composition. Since the surface of Venus is hot enough to melt lead, and no spacecraft have survived on the surface for longer than a few hours, there just isn t the information about Venus internal composition. Scientists can calculate the density of Venus, though. Since it s similar to Earth, and the other terrestrial planets, scientists guess that the internal structure of Venus is similar to Earth. One of the big differences between our two planets, however, is the lack of plate tectonics on Venus. For some reason, plate tectonics on Venus shut down billions of years ago. This has prevented the interior of Venus from losing as much heat as the Earth does, and could be the reason Venus doesn t have an internally generated magnetic field.

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15 The Twin of Earth Venus and Earth, have a lot in common a solid surface you could walk on, a comparable surface composition, an atmosphere and a weather system. Venus Mass x kg Earth 5.98 x kg Radius. 6052km. 6378km Density 5250kg m kg m3 Because of the similar size, mass, density to Earth, we often call it, the sister or the twin of Earth. However, there are still lots of differences between this two planets.

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17 Differences between the twins Venus is the second planet in the solar system. Which is 108 million km to the Sun.Earth is the third. Therefore,Venus is 42 million km closer to the Sun than Earth. A little shorter in distance, but a huge difference in temperature Being closer to the sun, Venus is a lot hotter than the Earth. While the average temperature on the earth is about 15 C, that on Venus is over 460 C. But, Venus is so hot that the temperature even higher than Mercury, the closest planet to the Sun. It is the hottest planet in our solar system. What make it so special?

18 The Atmosphere It has the densest atmosphere of the four terrestrial planets, consisting of more than 96% carbon dioxide. The mass of the atmospheric at the planet is 93 times that of Earth's. With a mean surface temperature of 462 C. It may have had considerable water and even oceans in the past, but these would have vaporized as the temperature rose due to a runaway greenhouse effect There is a thick layer which mainly consists of SO2 and sulfuric acid droplets above the CO2 layer. This outer layer can reflect 90 persent of the sunlight. Which means even it is closer to the sun, but it may be darker than the Earth. It also prevent visual observation of the surface. What's more, even though the surface is so hot that no life can survive, however it is possible that some life consist in the lower and middle part of the atmosphere.

19 Escape Velocity, Mass and density On Venus, with respect to Venus gravity, the escape velocity is 10.3 km per second Then, with respect to Sun's gravity, the escape velocity is 49.5 km per second The mass of Venus is * kg Venus have a strong density, it is 5250 kg per m3. Only Earth's and Mercury' density is bigger than Venus's. Even Jupiter and Neptune are way more larger than Venus, the density of them are still not stronger than Venus's.

20 Albedo of Venus In real life, objects in the Solar System have albedo values between 0 and 1. And in the case of Venus, the albedo is Venus has the highest albedo of any major planet One of the reasons that Venus is so bright in the in our solar system. It reflects about 70 percent of sky is because of its high albedo. This albedo the sunlight striking it. When the moon is close to comes from the permanent cloud layer that full in Earth s sky, it can look a lot brighter than surround the planet. These clouds are made up of Venus, but the moon reflects only about 10 sulfuric acid that reflect much of the radiation that percent of the light that hits it. It appears bright falls upon them. to us only because of its nearness to Earth.

21 Thanks!