Questions tagged [earth]

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

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3
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1answer
80 views

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 ...
2
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1answer
58 views

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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2answers
4k views

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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1answer
67 views

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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0answers
53 views

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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36 views

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/...
8
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1answer
294 views

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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3answers
224 views

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 ...
4
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3answers
136 views

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 ...
2
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1answer
86 views

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 ...
2
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1answer
142 views

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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1answer
89 views

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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1answer
91 views

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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43 views

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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40 views

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?
2
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1answer
76 views

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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2answers
81 views

Does the Lagrange L1 point have a 'size'?

Like in cubic kilometers, what is the size of L1 "area of influence"? being unstable I guess that size can vary?
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3answers
213 views

When did people discover that the Earth is not an ideal sphere, but a little flattened?

When did people discover that the Earth is not an ideal sphere, but a little flattened? And if you know, who was the first person to discover it?
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1answer
101 views

Storm on Earth vs. storm on Jupiter?

Why is the storm on Jupiter much stronger than storms on Earth and why don't the storms on Earth get as big as Jupiter's great red spot
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29 views

Angle of the Sun during winter solstice

What is the angle of the Sun on the eastern horizon at 35° latitude if it is the winter solstice?
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4answers
160 views

What is the size of the largest asteroid orbiting the Earth, other than the Moon?

It seems odd to me that no other asteroid around the Earth is even close to the size of the Moon. Anyone have any idea about the size and orbit radius of Earth's "second moon" ?
2
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1answer
75 views

Perihelion dates and parameters

I have to find the perihelion and aphelion data for the 20th century for Earth. I found this table http://www.astropixels.com/ephemeris/perap2001.html, but no such table for the past century. I ...
2
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2answers
116 views

Are there any planets or objects orbiting in Goldilocks zone?

I was wondering whether there were any objects that orbit the "goldilocks zone" besides our home planet earth, and how the goldilocks zone of our solar system is defined.
2
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1answer
87 views

How Long Will Earth's Year be When Our Sun Goes Red?

We live in a planet that orbits 93 million miles from a G-type main-sequence star, or "yellow dwarf". That is far enough for a revolution of 365 days. Such is the case of Kepler's Third Law of ...
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1answer
140 views

Is it possible that Venus was once a rogue planet? [closed]

As Venus rotates in clockwise direction, while other planets rotate in anti clockwise direction: Is it possible that Venus was once a rogue planet?
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2answers
105 views

Does the magnetic field of earth restore?

The magnetic field of earth protects us from solar wind as we know it, but after the solar wind interacts our magnetic field. Does the magnetic field of earth restore after it deflects the solar ...
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2answers
207 views

Can an Earth-like planet survive if our Sun went Supernova?

First, I would like to point out, yes, our sun does not have enough mass to be a candidate for Supernova, this is a scenario were our sun is though, and after the various life cycle stages of the sun ...
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1answer
96 views

Why do transits of Earth across the Sun seen from Mars follow a pattern of occurring after 26, 79 then 100 years?

According to this answer transits of Earth across the disk of the Sun as seen from Mars: The (Arthur C.) Clarke story is quite correct. Earth (and Moon) would transit the sun from the viewpoint of ...
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1answer
94 views

When and where are we exposed to most cosmic radiation?

I understand the mechanical dynamics of being faced away from the Sun at night, having a lower altitude, not being in the weak points at the poles in the atmosphere, being in a valley and others ...
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3answers
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How well would the Moon protect the Earth from an Asteroid?

Would the Earth fare better if the Moon blocked the meteor, comet, rogue planet, or otherwise rather than a direct impact? At what point would the Moon's debris would be an extinction event? The ...
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1answer
68 views

Earth's perihelion vs winter solstice [duplicate]

I found that Earth's perihelion occurs roughly two weeks after winter solstice similar thing happens for summer solstice and aphelion. I understand what those terms mean but I don't understand the ...
6
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1answer
147 views

When did the first annular eclipse happen?

A few hundreds of millions of years ago, the moon was closer to the Earth than it is today and hence was of a bigger apparent size. This made every solar eclipse either total or partial. Over the ...
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4answers
213 views

Could the solar system survive in a void?

If the solar system were suddenly placed in the middle of a large void... would everything still function as normal? Would we even notice any difference here on Earth apart from the night sky? ......
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3answers
93 views

What effect does Earth losing a part of its mass have, is there an impact on the Earth's orbit around the Sun?

This is a random question that popped into my mind. I'm not a physicist or astronomist, however, I am genuinely curious. Also, this is not intended as a science fiction question, but an actual science ...
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1answer
126 views

What keeps the planets of the solar system moving in their fixed orbits?

Models of the solar system show each planet moving around on its own orbit. Is is really because of the Sun that every planets remains in its own fixed orbit?
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2answers
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Can someone tell me what is exactly the curvature per mile in earth? [closed]

Earth is a planet as we all know.Astronomy examine the planets too.So whats the point looking for answers on other planets if you cannot give an answer to a simple question like the following. Basic ...
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3answers
172 views

Origin of heavier elements on earth?

Earth is part of Solar system, which is said to have originated from condensation and mutual attraction in dense clouds of gasses and dust. If Sun is basically more than ninty percent hydrogen and ...
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0answers
85 views

Orbital decay of the Earth's orbit and Earth's moving closer to the Sun

If we consider orbital decay of the Earth's orbit, then can we counter argue with the following reasons? Due to tidal effects transferring small amounts of angular momentum from the Sun's spin to ...
3
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1answer
224 views

Word for blue ring around the Earth

From certain positions in outer space the Earth will appear to have a blue ring around it when the viewer is in the shadow of the Earth and sunlight is passing through the atmosphere. Here is a ...
2
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2answers
229 views

Does the sun have cycles causing temperature changes on Earth?

Can the Sun go through seasons or cycles to cause a temperature change? Could the Sun have to go through any kind of thermal cycle to change the climate on Earth and by how much?
2
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0answers
86 views

How to caclulate the chinese Three Gorges Dam impact on Earth rotation? [closed]

According to this January 2005 NASA JPL News item NASA Details Earthquake Effects on the Earth, the Three Gorges Dam has slowed down Earth's rotation by 0.06 microseconds per day. Having that weight ...
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1answer
1k views

Are these real paths of planets as traced from Earth?

Few days a go, I came across these two pictures of paths of planets as observed from Earth. They have a perfect geometric shapes. Actually, to me they look so beautiful and perfect, that they appear ...
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3answers
245 views

Why is the equinoxes only 2 days and not more?

The earth is tilted at 23.5 degrees which means that in the solstices the north/south hemisphere is more radiated by the sun and the tilt to the sun is maximum. In the equinoxes, the tilt is not ...
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2answers
208 views

Diamonds in Neptune?

In this publication from 1981, was shown that Neptune is raining diamonds: Many of the current models of Uranus and Neptune postulate a three-layer structure, consisting of an inner rocky core, a ...
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1answer
46 views

Seasonal effect based on Earth position [duplicate]

I know that Earth rotates around the Sun in an oval route: And I know the seasons happen, because the axis of the Earth is not vertical. I think it is 23 degree slope. How come the distance from the ...
5
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1answer
186 views

Why is Earth's rotation considered fast?

I'm currently reading Atom (Krauss book), and in chapter 11 there is this text: This collision can explain many things, including the high rate of spin of the Earth (the grazing collision would ...
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3answers
10k views

If Earth is tilted, why is Polaris always above the same spot?

Why is Polaris, the North Star, always above (or near) the North Pole? If Earth is tilted, Polaris' path should be in winter 23 degrees away from its path in summer, or not?
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2answers
82 views

Should the sun appear very low in the horizon if its path is always between the two tropics?

If the sun never rises above the tropic of cancer and never goes bellow (southern) of the tropic of capricorn then it seems that it should appear to the observer lower and lower in the horizon for as ...
2
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1answer
150 views

What is the origin of the term “plane of the spirit level”?

I have heard the term "plane of the spirit level" e.g. the sun's shadows is X degrees to the plane of the spirit level to signify the surface of the earth and I see it is a common term used in ...
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1answer
105 views

South of the tropics, where does the sun's noon shadow point?

If I understand correctly, in countries to the north of the tropics the sun's noon shadow points north. What happens south of the tropics? Is it pointing south?