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Questions tagged [earth]

Questions regarding the planet on which humans live; the third planet from the Sun.

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If our earth hits Jupiter would it completely explode because of its methane atmosphere? [closed]

Considering that methane's composition in Jupiter is mere 10% or so but is it still enough to trigger a huge explosion? And is there enough oxygen(From earths atmosphere) for that to happen?
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How long will a ball of ice stay in orbit around Earth? [closed]

How big would a ball of frozen water need to be to last one orbit? How would atmospheric drag effect the ball of water? https://space.stackexchange.com/questions/32188/what-is-the-darkest-orbit-...
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In astronomy Is there a name for the exact time between solar noon and sunset?

Like there are names for various events such as sunset, sunrise, solar noon, solar midnight, astro, nautical and civil twilight, what exactly is name for time between sunset and solar noon. Afternoon ...
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If a giant object would approach the Earth, would Earth start to turn faster or slower while the object starts to become nearer and nearer?

I am asking myself this question: if a giant celestial object would approach the Earth, would Earth start to turn faster (then day duration would be diminished) or slower (day duration increased) ...
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Why does earth's north pole roughly point in the same direction throughout the year?

I know there is a gioscopic explanation but I was under the impression that Earth is traveling in a straight line through space that has been curved by our sun's gravity ,so my question is why doesn't ...
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Just out of curiosity. What's this curvature per unit length for a sphere? I see a lot of flat earthers using it.

I've seen most flat earthers mention if earth was a sphere the earth should curve at x value per unit length. Is that even a proper logic? Radius of curvature is constant for sphere and a circle of a ...
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Can one detect from earth that angular momenta of its axial rotation and its orbital rotation are “almost parallel”?

I mean that the angle between these angular momenta is acute as opposed to obtuse (23.5 and not 180-23.5), so that the rotations are "roughly in the same direction". Related but distinct question -- ...
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What does it mean that the Sun`s rotation axis is: RA 286.13° , Dekl: 63.87°?

first post here. I found 1 related Question, which has not solved my Problem. SHORT QUESTIONs VERSION: Suns axis is 7,25° tilted from the ecliptic. But in which direction? LONG QUESTION: Nasa ...
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What cosmic disaster is most likely to happen? [closed]

Of all the different ways that the Earth can be destroyed what ways is the most likely that could happen?
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Calculate position of the Sun in ECEF

I'm making a very basic orbit simulator in C# using the Helix Toolkit. I want to position the Helix lighting object at the sun, but also be able to calculate solar eclipse by the moon and earth for a ...
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Could the Moon sit on the Earth?

Let say that the Earth's Moon was knocked out of orbit and landed on the Earth with some damage but not world ending. Would Earth's atmosphere envelop to include the Moon? Would the moon sink into the ...
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What is the Terra phase?

Does the Moon have a night and day like Earth? When sitting on the Moon and viewing the Earth what does it look like when the Earth goes through phases like the Lunar Phase? How does the sun travel ...
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Reversal of magnetic poles of earth

When the magnetic poles of the earth get reversed, does the earth keep on revolving in the same direction or does it start revolving in the opposite direction?
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How much magnetic attraction is there between the Sun and Earth?

How much magnetism is there between the Earth and Sun? Would the distance from the Sun differ for not the Earth iron core and how much?
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What's a good model for the vernal equinox year? Can it increase forever?

Duncan Steel (2002) makes an interesting argument that the notion of year is (1) somewhat arbitrary and, more interestingly (2) one notion of year can increase while another decreases. His examples ...
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Would this effect occur if an ice planet was put into orbit or trajectory? [closed]

Imagine an earth getting warmer. Humans decide to make their homes ready for a voluntary ice age. All the space agencies work together to get an icy planet/moon into our orbit between us and the sun. ...
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How big should be a piece of neutron star to reach Earth's mass?

Imagine a neutron star could be broke into pieces. How big would be the piece matching Earth's mass?
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Site to see direction to the Voyager by entering time and coordinates of my position on the Earth? [closed]

Where is Voyager relative to me right now in realtime?
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1answer
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Water Ice on Meteorites

I was reading an article by David O'Brien et al. where it stated "in meteorites only the water bound to the silicates can be found, all the water ice having been lost, whereas on asteroids water ...
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What is Earth's average temperature as a whole? [closed]

I would like to know, what is the average temperature of Earth as a whole planet, not just its surface temperature. Hope the following scenario will make it more clear what I mean: Imagine, that we ...
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Why is the shadow of the earth not visible during sunsets?

I would imagine that during a sunset, for a brief moment of time, there would be a shadow of the earth seen in the clouds but I have never seen this. Why does it not happen?
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1answer
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Calculate eclipse days and duration of satellite

If a satellite is revolving in a GEO orbit, then what will be the eclipse duration for it? How to calculate when the satellite will enter the dark side of the Earth? Any formula or online tool would ...
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How did the solar system get its angular momentum? Why did Earth not fall into the Sun at the start? [duplicate]

I know that Earth is always falling towards the Sun, but due to its sideways momentum it just misses always. But how did it all start? To go into detail, when the gas cloud with zero angular ...
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Simple experimental evidence that Earth revolves around Sun

What are the simplest experiments or calculations that give evidence that the earth revolves around the sun? Can you please explain them and reference the history? Many simple explanations such as ...
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Could Earth have been seeded with life? [closed]

The earliest life on Earth is thought to have began shortly after its formation (a few hundred million years after, by fossil evidence, and this while the late heavy bombardment was raging). With the ...
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Why do photos of Earth always have a black background?

if we are in the milky way, and people are able to take photographs from Earth that look like this: Then how come almost all of Earth's photos look like this? In the first photo, we are seeing what ...
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Precautions when retrieving material originated from space

I'm assuming that when retrieving a meteor for study and later display, there are precautions taken against possible radiation coming from it. Is my assumption correct and are there other precautions ...
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Do we know how old the matter that makes us is?

Last weekend, I had the pleasure of visiting an observatory where there was a series of lectures to cover up the fact that there was too much cloud cover to actually observe much at all. One of these ...
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Why does each and every planet of our solar system have an unique axial tilt angle?

Why do planets have an axial tilt? From the above image we can see that each planet's axial tilt angle varies and differs from the others. What was the cause of this, was this from the beginning of ...
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How to calculate the altitude of the Celestial Equator from an observer's latitude? Exam question

When observing from a latitude of 50 degrees North on Earth, the Celestial Equator will have a maximum altitude of: Answer: 40 degrees I've looked this up and it says something about the observer's ...
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Given sunrise, noon, sunset, longitude and latitude can I calculate the “hight” or “ascension” of the sun?

I'm trying to make a simple app for my own use to be able to check which of my favorit restaurants have outdoor seating sun and for how long etc. Given the data in the title (sunrise, noon, sunset, ...
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6answers
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Would things be exactly the same if the Sun was orbiting the Earth and the Earth was in the center of the Solar System?

Would things be the same if the Sun was orbiting Earth and the Earth was in the center of the Solar System, or would there be any big difference? It seems like why people before thought the Earth was ...
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Why isn't the Sun hollow? [closed]

[Edited to remove incorrect geological assumptions] The sun is self-rotating, i.e. it spins on its axis. When something spins, there's an apparent force away from the centre, and matter gets flung ...
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Why does the Earth's axial tilt create an east-west variation in the analemma? [duplicate]

I've been reading about the Earth's analemma from Wikipedia, and I am having trouble visualizing one component. Let's build up to my question. If the Earth had a circular orbit and no axial tilt, the ...
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Calculate eccentricity from apside altitudes? [closed]

I need to calculate the eccentricity of a satellite orbit with only the apside altitudes (height above the surface of the Earth), 400 and 1500 km. However, I don't know the semi-major axis ($a$) or ...
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How old is the oldest light visible from Earth?

Because light can only travel so fast, all of the light we see in the sky was emitted at a previous moment in time. So if for example we see a supernova or some other great stellar event, by the time ...
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When the asteroid hit the earth 65 mya did the earth's gravity pull change? By how much?

When the asteroid hit the earth 65 million years ago, did the earth's gravity pull change? By how much?
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What does the angle between plane of earth's orbit and ecliptic vary between?

What does the angle between the plane of the earth's orbit and the ecliptic (now about 23.5 degrees) vary between, and over what time scale?
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How can Earth-Sun Lagrange points L1 & L2 even be semi stable considering the moon?

I know that the Earth-Sun Lagrange L1, L2, and L3 points are not considered stable over longer periods, especially when compared to L4 and L5... But, with the moon orbiting the Earth in the general ...
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Mass accumulation rate and orbit-time of earth

According to me following reason of mass accumulation of earth has been completely overlooked so far. The sunrays that fall on the oceans travel deep into water and finally get converted into mass ...
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Effect of the obliquity of the ecliptic / tilt of the Earth on the equation of time

In an attempting to answer the question “why aren’t changes in sunset and sunrise times symmetrical around the solstices ?” I’ve got stuck on being able to explain the effect of the obliquity of the ...
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Is the flat earth cosmology scientifically justifiable today? [closed]

With binoculars or telescopes you'd be able to see to other countries if the earth were flat. And looking out at the ocean we can see where the earth curves and things like the top of ships, not the ...
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What is the distance of the Earth's orbit around the Moon?

I realize the Earth and the Moon both orbit around their shared center of mass, and that in the case of the Earth and Moon this center is "inside" the Earth. However, I'm looking for an approach to ...
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How close would the sun have to get to Earth for there to be severe consequences?

According to earthsky.org the Earth gets 3 million miles closer to the Sun than its usual distance of about 93 million miles on average. My question is, how close would the earth have to be to the ...
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Are there currently any planned or proposed missions to measure the gravitational fields of other planets in our solar system?

I just recently found out about the GRACE Nasa mission which basically mapped out the gravitational anomalies of earth as well as serving extensively in the study of earths geology and the movement of ...
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5answers
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Why is sun's photosphere a million times less dense than air at the surface of the Earth?

Sun's photosphere is about 19 times as hot as Earth's surface. (Source: http://solar-center.stanford.edu/vitalstats.html) But Solar surface gravity is about 28 times terrestrial surface gravity. So,...
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What will the last day of humanity look like? [closed]

It's certain that human life on Earth will not go forever. Therefore there will be one last generation of humans on Earth. How will life look like for last few generations approaching the end? How ...
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Binary Orbit around the Earth?

Is a orbit possible where 2 objects going in opposite directions can intersect repeatedly with minor course corrections?
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Why is Earth a sphere? [duplicate]

Earth (and all of its 'neighbors') is a spheroid. Why is this? Earth could've been a cube, a tetrahedron (pyramid) or really any shape! But why a sphere?
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Temperature of Earth if tidal locked with the Sun?

Assume the Earth somehow stopped spinning once every ~24 hours, and instead started rotating at ~365 days per rotation, so it effectively would end up being tidal locked with the Sun. In this ...