36 votes
Accepted

How do we know the asteroids formed at the same time as earth?

what evidence do we have that the asteroids indeed formed at the same time as earth? It depends on what is your definition as "the same time". The formation of the solar system and Earth did not ...
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  • 22.1k
30 votes

How and why did the oceans form on Earth but not on other planets?

Your assumption that there is not a lot of water elsewhere in the solar system is incorrect. According the this article on NASA's website; Missions in recent years have overturned our view of a dry ...
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28 votes
Accepted

Would the Earth function the same spinning the other way?

That would have many consequences. For example the Coriolis force would change the sign. Thus wind around pressure systems would switch the direction from north and south hemisphere, but also the ...
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  • 1,662
25 votes
Accepted

How and why did the oceans form on Earth but not on other planets?

The water was already present when the Earth assembled itself out of the accretionary disk. Continued outgassing of volcanoes transferred the water into the atmosphere which was saturated with water. ...
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  • 3,876
24 votes
Accepted

What is the fastest the Earth has ever spun?

The speed of rotation of Earth is controlled by its angular momentum. And the conservation of angular momentum is a very serious law of physics (perhaps even stricter than conservation of mass). So in ...
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23 votes

Would the Earth function the same spinning the other way?

Depending on the assumptions you make, the Moon would suddenly have a retrograde orbit. If the moon had a retrograde orbit, it would have tremendous consequences. Retrograde orbits tend to become less ...
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  • 331
21 votes
Accepted

What factors determine the number of Hadley cells for a planet?

Well for one, this will surely be the speed of planetary rotation and the wind speeds your atmosphere can generate in North-South-direction. In my understanding those cells form as N-S winds flow and ...
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20 votes
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Is there geological evidence that the moon once collided with the Earth?

Is there geological (or other physical) evidence here on Earth that confirms the moon once collided with the Earth? No, there isn't. This is, however, plenty of evidence that the moon formed due to a ...
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  • 1,787
18 votes
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Will the Earth ever stop rotating?

The short answer is "Probably Yes". The longer answer is that it is debatable whether Earth's rotation will become tidally locked to the moon due to tidal drag, at which point it will not be rotating ...
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17 votes
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Why do Earth and Venus have different atmospheres?

Note: This response is bereft of references. I'll try to add them later. There is no definitive answer. There are a lot of conjectures, however. Whatever the cause, the Earth is markedly void of ...
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17 votes
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How bad is geo-engineering?

The bad part about geo-engineering are the unknown unknowns, to paraphrase a certain US politician. Our climate models are wrong. All models are wrong, but some are useful.. Our models are useful, ...
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  • 11.1k
16 votes

Are there any photographs of mountains without significant erosion (on Earth or otherwise)

Here's how astronomers of the late 19th century thought the Moon would appear: Recreations in Astronomy by H. D. Warren D. D., published in 1879, via http://en.wikipedia.org/wiki/Selenography. Here'...
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15 votes
Accepted

Why does the earth spin clockwise?

Earth's Spin Earth rotating clockwise is the result of a chain reaction that started when Earth's star formed as the result gas clouds collapsing. During the collapse of the gas, one direction was ...
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  • 4,561
14 votes

Why does the earth spin clockwise?

If you ascribe to the giant impact hypothesis, which most scientists do, whatever rotation the Earth had prior to the formation of the Moon was lost thanks to that 'giant impact'. That was a massive ...
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14 votes
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Plate Tectonics: Is it possible to have an ocean-continent divergent boundary

The oceanic plates are themselves formed from the divergent boundary, so probably not. Even if a new rifting occurred exactly at the boundary, the result would eventually be that the ocean floor ...
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  • 5,896
13 votes

Is there another explanation than an asteroid/volcano for the extinction event on Earth millions of years ago?

Look at Earth's orbit around the Sun. The orbit is an ellipse, but Earth never gets close enough for the Sun to cause any mass extinction. The Earth orbits the Sun every year, and because the orbit is ...
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  • 231
12 votes

Is Earth an organism?

[I am going to preface this by saying that I am not in one camp or the other in this discussion, as I think there are pros and cons to each side] This links to the "Gaia Theory" proposed by James ...
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  • 171
12 votes

What properties must a rocky body possess in order to exhibit plate tectonics?

Plate tectonics appears to require multiple factors all arraigned in feedback loops. The planet must be large enough that it's surface to volume ratios is low enough to trap enough heat from ...
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  • 561
12 votes
Accepted

Why does helium-3 stay in the moon and not escape from it?

The Moon is not "full" of helium-3. 3He is at most fifty parts per billion of the lunar regolith1 and that "high" concentration pertains only to permanently shadowed craters. The Moon is bombarded by ...
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12 votes

How do we know the asteroids formed at the same time as earth?

The formation of a T-Tauri star spells the beginning of the end of the protoplanetary disk from which planets and asteroids can form. The end is nigh when that star ignites. The large solar winds and ...
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12 votes

Would life on Earth survive without the Sun?

The answer is No, the Earth would not remain in any recognizable form without the Sun. There would still be a husk of a dead planet with a small amount of energy coming from the residual heat of ...
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11 votes
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Why does Mars' experience an 'ice age' at high axis obliquity, when Earth experiences an ice age at low axis obliquity

If I understood it correctly, the important point is the temperature difference between mars and earth. On earth increasing obliquity, as you wrote, leads to increased melting of ice, ie. you increase ...
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  • 529
11 votes

How do archaeologists address time dilation when analyzing carbon dating results?

For all intents and purposes, the Earth represents one frame of reference, as @kwinkunks states. Therefore no effect. Yes the gravitational field on top of a mountain is slightly less than at sea ...
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  • 3,823
11 votes

How do archaeologists address time dilation when analyzing carbon dating results?

How do archaeologists address time dilation when analyzing carbon dating results? They don't. There is NO point in doing so. Compare two hypothetical substances at the peak of Chimborazo (the highest ...
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11 votes
Accepted

Will dust storms be more frequent in the future?

Most dust storms occur down-wind from areas with a lack of moisture, little vegetation, and high soil content. Vegetative roots help to keep the soil intact when there is a lack of moisture. So any ...
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  • 12.7k
11 votes
Accepted

Diamond at the core of Jupiter

I would think this is questionable, though we don't have a definitive answer yet. We usually think Jupiter has a roughly solar composition, which according to the solar abundance measurments of ...
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11 votes

Eclipse, Hurricanes, Earthquake....Related Events?

The occurrences of Hurricanes, Harvey, Irma, Katia and Jose, east of Mexico and a magnitude 8.1 earthquake southwest of Mexico within a few weeks of the American solar eclipse of August 21, 2017 are ...
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