Dust clumped together to form rocks, rocks smashed together into boulders, and mountain-sized objects became protoplanets. But eventually, Venus became the dominant object in the region, sucking in everything with its gravity. We know that Venus was probably the victim of a large collision because it rotates in the opposite direction from the rest of the planets in the Solar System.
A large collision could have turned its rotation backwards. Instead, scientists measure the age of meteorites that have fallen to Earth.
After analyzing hundreds of objects, scientists have found that they all formed at approximately the same time. The planet started out as nothing more than dust, but then these dust particles collided together, forming larger grains, pebbles, rocks, boulders and eventually planetoids. For the first few millions years, the Solar System was a dangerous place with these planetoids constantly crashing into one another.
Eventually the number of objects in the Solar System was cleared out; they were either swept up into the planets, or kicked out of the Solar System by gravity. And we were left with the planets we have today. Astronomers know that everything in the Solar System including Venus is roughly 4. The complete cycle, however, new to full, takes days, while our Moon takes just a month. And it was this perspective, the phases of Venus first observed by Galileo through his telescope, that provided the key scientific proof for the Copernican heliocentric nature of the Solar System.
Spending a day on Venus would be quite a disorienting experience — that is, if your ship or suit could protect you from temperatures in the range of degrees Fahrenheit Celsius. For another, because of the planet's extremely slow rotation, sunrise to sunset would take Earth days.
And by the way, the Sun would rise in the west and set in the east, because Venus spins backward compared to Earth. In winter, the tilt means the rays are less direct. No such luck on Venus: Its very slight tilt is only three degrees, which is too little to produce noticeable seasons. A critical question for scientists who search for life among the stars: How do habitable planets get their start? The close similarities of early Venus and Earth, and their very different fates, provide a kind of test case for scientists who study planet formation.
Similar size, similar interior structure, both harboring oceans in their younger days. Yet one is now an inferno, while the other is the only known world — so far — to play host to abundant life. The factors that set these planets on almost opposite paths began, most likely, in the swirling disk of gas and dust from which they were born. Somehow, 4. Several might well have moved in closer, or farther out, as the solar system formed. If we could slice Venus and Earth in half, pole to pole, and place them side by side, they would look remarkably similar.
Each planet has an iron core enveloped by a hot-rock mantle; the thinnest of skins forms a rocky, exterior crust. On both planets, this thin skin changes form and sometimes erupts into volcanoes in response to the ebb and flow of heat and pressure deep beneath. Other possible similarities will require further investigation — and perhaps another visit to a planet that has hosted many Earth probes, both in orbit and briefly on the surface.
Subduction is believed to be the first step in creating plate tectonics. Magellan saw a land of extreme volcanism. The orbiter saw a relatively young surface, one recently reshaped in geologic terms , and chains of towering mountains.
The broiling surface of Venus has been a topic of heated discussion among planetary scientists. The traditional picture includes a catastrophic, planetwide resurfacing between and million years ago. In other words, Venus appears to have completely erased most traces of its early surface.
The causes: volcanic and tectonic forces, which could include surface buckling and massive eruptions. But newer estimates made with help from computer models paint a different portrait. While the same forces would be at work, resurfacing would be piecemeal over an extended time.
The average age of surface features could be as young as million years, with some older surfaces mixed in. Venus is a landscape of valleys and high mountains dotted with thousands of volcanoes.
Its surface features — most named for both real and mythical women — include Ishtar Terra, a rocky, highland area around the size of Australia near the north pole, and an even larger, South-America-sized region called Aphrodite Terra that stretches across the equator. One mountain reaches 36, feet 11 kilometers , higher than Mt.
Notably, except for Earth, Venus has by far the fewest impact craters of any rocky planet, revealing a young surface. Or stroll through a deep canyon, Diana, named for the Roman goddess of the hunt.
Tesserae, terrain with intricate patterns of ridges and grooves that suggest the scorching temperatures make rock behave in some ways more like peanut butter beneath a thin and strong chocolate layer on Venus.
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