Questions tagged [earth]
Questions regarding the planet on which humans live; the third planet from the Sun.
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Was the Geocentric Model correct at all?
It's easy to find resources stating that the heliocentric model is right and geocentric is wrong.
But how wrong was it? Was it correct in any way?
It was built on incorrect assumptions, but despite ...
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Why does time pass faster in moon than the earth?
One of my friends said that,
time passes faster in moon than the earth
Why does time pass faster on the moon than on the earth?
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If the solar system is nearly flat, then why don't all the planets appear to lie on the same axis when viewed from earth?
For instance, consider the image below. The location of the planets seem to be so random relative to Earth. If the solar system was indeed flat, then I would expect the planets to lie on the same '...
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Can we change Earth's orbit with modern technology? [closed]
It is well known that, according to Newton's 3rd law, spacecrafts entering or leaving Earth provoke tiny (insignificant) changes to Earth's orbit (see related question here).
My question is about ...
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Can a single impact event trigger a runaway greenhouse?
Somewhat related to this question: Is the Earth going to evolve towards Mars' fate or Venus' fate?
Human civilization may be fragile, but life itself is extremely resilient, with extremophiles and ...
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Has the computed change of the axial tilt ever been measured?
Earth, the 3rd planet from the Sun, sometimes faces earthquakes and seaquakes that are so strong that they reportedly change the axial tilt and/or the rotation velocity. These changes are merely ...
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As the Moon and the Earth are predicted to get into tidal lock, how slow would the Earth rotate?
This answer to Will the Earth ever be tidally locked to the Moon? supports the widely held thinking that during the Sun's red giant phase or later the Earth and the Moon should be tidally locked to ...
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How can the Earth and the Moon be in synchronous rotation if the Moon won't be in geostationary orbit?
It is said that the Moon moves away from Earth and that during the Sun's red giant or white dwarf phase the Moon will be about 40% farther than now and in a synchronous rotation ("hantle rotation&...
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Solar flares/CME dangers to life?
I know a repeat of the 1859 Carrington Event (coronal mass ejection) would pose a severe risk to power grids and telecommunication networks but wouldn't pose an immediate threat to life.
If a large ...
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Why the earth orbits the sun from X to -X and not the opposite [closed]
I wonder all the time, why the earth orbits the sun as expected from east to west(X to -X) ?
It could be different, for example from the west towards the east .
What would happen if that were the case?...
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Retrogradation movement of planet Mars relatively from Earth by Copernic
I have a simple question : on the following figure:
I don't understand on the right figure why there is a progressive shift on the right when we start from step 1) to step 9). I guess there is an ...
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Isn't it absurdly unlikely that our Moon would constantly be "facing" us? [duplicate]
I never thought about this until recently, but our Moon is constantly rotating in such a way that it happens to perfectly be "looking at us" at all times. That sounds incredibly unlikely to ...
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Keplerian Elements for the Moon and Earth around their Barycenter
So I'm looking to replicate the inner Solar System to a decent degree of accuracy. So far I've been utilizing the Keplerian Elements and Equations for the planets, as shown here. There is one issue ...
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How will the Solar tides affect the Earth's rotation once it is tidally locked to the Moon?
It is my understanding that the tidal forces of the Moon acting on Earth cause it to slow down its rotation and, because angular momentum is conserved, the Moon's orbit subsequently expands. This ...
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Position of the Sun in the constellation Pisces around the year 1500
I am reading a book on ancient astronomy and it claims that around the year 1500 the position of the sun, at the time of the spring equinox, was on the tail end of the second fish in the constellation ...
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Is it ever possible to see Earth's shadow on other planets?
Is it ever possible to see Earth's shadow on other planets?
How would the shadow present, and what would be the magnification, equipment, or other conditions necessary to see it?
Is there any way of ...
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What would happen to the Earth if the orbit of another planet in the Solar System was disrupted by a cataclysmic collision with a large body?
There's plenty of speculation about what would happen if a large asteroid collided with the Earth itself, but less about the effect on Earth of a large asteroid or even a moon or minor planet ...
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Lights moving fast and in a straight line coming from the northwest headed southeast tonight at 9:15CST [duplicate]
What is going on tonight?
Bright lights in the same high orbit moving very fast across the night sky from Northwest heading southeast...then 10 minutes later same line but far fewer almost in ...
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Calculating the orientation of the night sky
How would one calculate the rotation/tilt of the earth to simulate the Night Sky in a self-written tool or app. I am trying to built an app for my telescope to show me on my phone what I am looking at....
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What are the sources of antimatter particles in the magnetosphere?
The PAMELA instrument detected antimatter particles in the Earth's magnetosphere. What are the sources of these particles?
The answer to Source of high energy cosmic particles outlines the sources ...
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Moon’s orbit shift
Has our moon’s orbit shifted since its formation? Has there been eclipses on the Earth since last ~4 billion years? In other words, was there a time when Moon's orbit was at an inclination to Earth's ...
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Is the equinox absolutely true east everywhere?
I've read that only only in the equinoxes do you get to see the sun rise in the exact east regardless where you might happen to be. However I think this is not absolutely true everywhere, but only in ...
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Can you provide a visual description of the sun rise?
The Sun rises in the east only two times a year. The other days, the Sun rises in the east, but a little bit to the north, or to the south. How can you know the degree of how much north or south it is?...
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Is a year really 365.24 days, or is it 365.2564 days like I remember?
The NPR News item and podcast Spring Starts Today All Over America, Which Is Weird includes the following:
But why isn't the time of the equinox the same each year?
The short answer is that the time ...
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How is an exoplanet characterised as "Earth-Like"?
Which features or characteristics are taken into account to characterize an exoplanet as "Earth-Like"?
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The size of the Earth
Has the earth always been this size apart from a few occasional additions from time to time.
Meteorites hitting the planet now don’t become part of it and the moon when it collided just spun of into ...
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How Does Earth Move In Relation To The Stars
In my simulation, I have stars scattered around Earth, all stars are the same distance from the center of the Earth and positioned based on their right ascension and declination like so:
I am ...
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When was the longest day on record?
The Earth's rotation is gradually slowing down. It was significantly shorter in the prehistoric past, but now we need to add a leap second every few years and we've not yet had to take any back. In ...
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Was the Earth-Sun distance ever calculated based on the time difference between night and day?
If we define sunrise and sunset as the time when the center of the Sun goes over the horizon then day time is a little bit shorter than night time because from a single point one cannot see a complete ...
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Are Sun-Earth L1 & L2 points generally considered outside the Earth's Hill Sphere?
This image from Wikipedia of the SE Lagrange points and the Hill Spheres suggests that the SEL points are outside the Earth's Hill Sphere. (The Hill spheres are the circular regions surrounding the ...
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What's the first written record of the moon being tidally locked to the earth?
I couldn't find references as to who first noticed (wrote down) that the moon was tidally locked to the Earth. This, to me, doesn't seem obvious from first glance, and looks like something only found ...
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If the earth lost 1/81th of its mass how would it orbit change? [closed]
If a planet becomes lighter, then I believe its orbit will change.
For example, the moon is 1/81 of the mass of the earth. So, if the moon disappeared, then the earth-moon system would lose 1/81th of ...
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Earth as a grain of sand
If Earth was a grain of sand in Buenos Aires
in what point in this observable universe map would be LA be?
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Where and when will someone on Earth be standing with the floor parallel to the Ecliptic plane?
I have been trying to figure this out and I think the answer might be - once per day for anyone living on the Tropic of Cancer or Capricorn. Is that right? To be clear - I want to know where on Earth ...
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What methods can high school students use to measure the radius of the earth?
I suppose they could split into 2 groups and use the shadow method from different latitudes.
Maybe they could also use the stars on the horizon at two different latitudes.
Is measuring a ship below ...
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What is the exact time of sun stay in each zodiac every year on sidereal year duration?
I tried to reverse engineer from astro-chart times at which sun stays in a zodiac.
Here is the list.
...
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Why are perihelion and the shortest day in the northern hemisphere different?
The orbit of Earth is elliptical and the nearest distance to sun is perihelion position. Should it not be the shortest day in the northern hemisphere?
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Age of earth relative to other planets
Relative to the average age of other known planets, is the earth young, old or in the middle? Does it make a difference if you compare the earth against nearby planets (say < 500 LY), or other ...
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Orbitally convenient Mars-to-Earth transit times?
Are there any peculiar solar system layouts that would result in highly efficient transits between Mars-to-Earth? I am aware of a Hohmann transfer orbit, but can other planets be used to "sling-shot" ...
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Astronomical events and Celebrations
In the past people celebrated important astronomical events and some of those events are still celebrated in some cultures and traditions.
For example: March/September equinox, New Moon, Winter/...
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What would the effects on or around Earth if Betelgeuse went supernova?
There's been a lot of news lately about Betelgeuse possibly exploding sooner than perhaps was expected. Some examples:
Guinan, Edward F.; Wasatonic, Richard J.; Calderwood, Thomas J. (8 December 2019)...
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Difference in gravity on both sides of the moon
How much (if any) difference in gravity would you feel if you are on the surface of the moon and:
standing right 'under' earth (exaclty between the moon and the earth) and
on the opposite side of the ...
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How long is the Sun closer to Earth then Mars is?
A recent question at Space.se has generated a few comments that are interesting.
But the answer to one particular comment to might address a lot of misconceptions.
I imagine the actual halfway ...
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Latitude of given altitude of Sun
From Question #6 of USAAAO First Round 2018
(1 point) For the following problem find the range in which the answer lies: on the day of summer solstice, on which geographic latitude is the sun ...
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Why do the magnetic field lines of the earth go from south pole to north pole?
I saw these figures and could not get why the magnetic field lines are not pointing from the north pole towards the south pole but they do the opposite.
Or also this picture which is about magnetic ...
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Earth's magnetic field vs. refrigerator magnet
According to this article:
The Earth's field ranges between approximately 25,000 and 65,000 nT
(0.25–0.65 G). By comparison, a strong refrigerator magnet has a field
of about 10,000,000 ...
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Solar degrees vs Calendar days [closed]
What is the difference between solar degrees and Calendar days. Is there any formula to convert one to another.
for example Starting from 1/1/2000
1/1/2000 + 300 calendar days=some date (easy)
1/...
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Simulate earth, moon, sun constellation with dates
I would like to simulate the three object distance, specifically the distance of the moon to both, sun and earth for further investigation into tide prediction.
What would be a good starting point ...
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Reason for Orbital Reflector [closed]
We know that last year, space X rocket took orbital reflector with it into the space. But what might be the reason behind launching this weird object into the space? Does it do any work there?
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How is Earth's gravity modelled?
The Earth does not have a defined geometric shape. Then how do space scientists who want to put a satellite in orbit model the gravitational field of Earth? Do they assume a single object with minute ...
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