Posted on 12/12/2017 10:53:55 AM PST by BenLurkin
According to a new study conducted by an international team of scientists, it may have something to do with a massive impact that occurred in the past. Since Venus appears to have never suffered such an impact, its never developed the dynamo needed to generate a magnetic field.
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According to the most widely-accepted models of planet formation, terrestrial planets are not formed in a single stage, but from a series of accretion events characterized by collisions with planetesimals and planetary embryos most of which have cores of their own.
Recent studies on high-pressure mineral physics and on orbital dynamics have also indicated that planetary cores develop a stratified structure as they accrete. The reason for this has to do with how a higher abundance of light elements are incorporated in with liquid metal during the process, which would then sink to form the core of the planet as temperatures and pressure increased.
Such a stratified core would be incapable of convection, which is believed to be what allows for Earths magnetic field. Whats more, such models are incompatible with seismological studies that indicate that Earths core consists mostly of iron and nickel, while approximately 10% of its weight is made up of light elements such as silicon, oxygen, sulfur, and others. Its outer core is similarly homogeneous, and composed of much the same elements.
To add to this state of confusion, paleomagnetic studies have been conducted that indicate that Earths magnetic field has existed for at least 4.2 billion years (roughly 340 million years after it formed). As such, the question naturally arises as to what could account for the current state of convection and how it came about.
(Excerpt) Read more at universetoday.com ...
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The scientific term for it is B$
can I still insert a Uranus joke?
The core materials are different between the two.
You’re right about that.
https://io9.gizmodo.com/heres-carl-sagans-original-essay-on-the-dangers-of-cl-1481304135
Stupid question. Assumes that planets of similar size must have the same attribute regarding the magnetic field.
The real question is why do scientists think they have an explanation for everything?
Uranus is right next to the Big Dipper?
i’ve heard that since high school cmon now XD
Earth has a magnetosphere because, long before the dinosaurs roamed the earth there were Monstermagnets. They died off and became the magnetosphere just like dinosaurs died off and became fossil fuels.
-PJ
Queue The Temptations...
Ball of confusion, ball of confusion...
Gawd, this is too easy.
I’ll wait for other posters...
That movie was a staple Saturday afternoon creature feature on one of the local Cleveland stations. It should be included in any top (or bottom?) ten list of really bad 1950’s science fiction films.
Exactly. Venus is the most "Earth-like" planet ever found. It is almost the same size and mass and has relatively close to the same orbit around the same star. From a few light years away you would think that Earth and Venus are identical.
Lack of a magnetosphere was one of Velikovsky’s predictions in the 1950s, among many other correct predictions about the physical nature of Venus. It had absolutely nothing to do with some ‘collision’, but rather the origin of the planet.
Worlds in Collision (Immanuel Velikovsky, 1950) gives an interesting theory on the origin and history of Venus. It relates to historical events on Earth 3500+/- years ago as well.
Whats up with that???
Heavier gases vs. Earth's lighter ones, and a time frame much shorter than our own (part of Velikovsky's theory).
What you wrote makes it even more miraculous that we are even hear and even more ridiculous that humans spend as much time doing what we do day in and day out. The chances of us even being here is infinitesimal, and we sit here and argue about nonsense.
Earth
No comparison.
In order for a planet to be truly ‘Earth-like’, it MUST have what the Earth received in the massive collision that created the Moon. And if you calculate the odds of that, it makes the Earth a MUCH rarer commodity.
Yep. Just check out the estimated 100,000,000,000,000,000 stars so far discovered in the universe and you will see that there cannot be any other planet anywhere like Earth because there just aren’t enough stars in the universe ... /s
Of course, the Earth-Moon collision, as well a the origin of Earth’s core, are all theories and you know what happens to theories in time, right?
So that means the earth was only 5000 miles in diameter once. I'd like someone to tell me what the composition of the layers was then. Were the supposed plates moving then too.
ML/NJ
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