Questions regarding the planet on which humans live, the third planet from the sun.

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Why Earthian atmospehere is so thin?

Venus is somewhat lighter then Earth, yet has a much thicker atmosphere. One would imagine that the following should be true: During the formation phase, all inner planets had captured as much gas ...
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0answers
19 views

How to read NOAA/NASA GOES satellite data? [migrated]

I requested satellite image data (GVAR_IMG) for a project that I am working on from the GOES satellite, but I don't know what format it's in or how to read it. When I open it with a text editor it is ...
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1answer
35 views

Why do some artificial satellites decrease and increase in brightness multiple times?

I just observed a satellite almost directly above me travel for a few minutes while constantly dimming and then getting brighter. It did this for about 3 minutes until it faded out. I also observed a ...
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1answer
56 views

How significant is a planet's density to the formation of life?

I'm doing some writing set on a fictional earthlike planet that for reasons needs to be substantially larger than Earth but can't have substantially higher gravity. I've been able to compromise with a ...
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1answer
79 views

How can they tell no asteriods will hit earth in the next hundreds years?

It has come to my mind this interrogation : How can they tell no asteroids (big enough to create damage) will hit earth in the next hundreds years? Because, so far, we were unable to get a clear ...
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1answer
147 views

How long until the Earth and Moon become a binary planet?

With the rate at which the moon is further receding into a higher orbit, how long until the barycentre between us and the moon leaves the earth, and going by the IAUs 2006 definition update, we become ...
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1answer
103 views

What will the last days of Earth be like?

The sun is a main-sequence star; as I understand it the sun will expand into a red giant in a few billion years. I have heard conflicting reports of what this entails - some sources I found say the ...
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1answer
46 views

what is the time mentioned after date (1962-07-03+02:00) the +02:00? [closed]

i was retrieving a some personalities birthday date through computer programming when i retrieve a person's birthday the result was ...
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2answers
115 views

Does a week represent something in astronomy? [duplicate]

I know that a day represent the time for the earth to make a full rotation around its own axis and a year is the time for the earth to make a full rotation around the sun. But does a week represent ...
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1answer
61 views

What is the projection of Earth's axis on the sphere with the Sun in center (see explanation)

Seems like it is the most convenient SE community for this question.. Imagine the sphere, witch center is the Sun and radius is, say, ~1.5 distance from Sun to earth (in arbitrary time, precise ...
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4answers
210 views

Does Sun have a reflection on Earth?

The new Google Maps1 presents an actual view of Earth, with the current position of Sun illuminating half part of Earth in real time. It is quite an exquisite view. My question is based on the ...
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2answers
104 views

What would be the practical consequences (on earth) if the Moon was not tidally locked?

I was thinking about the fact that all the largest Solar System moons are tidally locked to its primary and this question arose.
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1answer
54 views

How much time comet is within the Earth's orbit? [closed]

Comet on the parabola orbit flies by Sun. I would like to know what is comet's full energy? What is its distance from Sun at perihelion?
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1answer
41 views

Asteroids in langrangian Points 4 & 5

There are Asteroids "trapped" in Jupiters Langrange points 4 and 5 called trojans and greeks. Are there any asteroids in the earths L4 and L5? Have we seen asteroids in Lagrange points of the earth ...
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1answer
108 views

Has the sun become way brighter the last years?

Up to last year, I never got blinded by the sun in everyday situations (e.g. running towards it), at no time of the year I was. But since last christmas, it occured to me more often that I cannot ...
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2answers
52 views

Would dark energy save the earth for a while as the sun heats up?

Would the expansion of space (e.g. dark energy) move the earth further away from the sun over time, possibly saving us for perhaps a few billion years as the sun heats up? Scientists now tend to ...
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1answer
64 views

What are the equations for an orbit with time as parameter?

I am preparing a talk on the Equation of Time, and I want to produce an animation of the movement of the earth around the sun, in an exaggerated ellipse, to illustrate the speeding up and slowing down ...
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1answer
114 views

Is there Dark Matter inside the Earth?

Since Dark Matter is assumed to interact gravitationally, it follows that the gravitation of massive regular matter bodies should have an effect on it. Even if it is otherwise weakly interacting with ...
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1answer
33 views

What is the distance between 2 cities? [closed]

Both Quito and Kampala lie on the Equator. The longitude of Quito is 82°30'W and that of Kampala is 37°30'E. What is the distance from Quito to Kampala? A) along the shortest surface path B) along a ...
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1answer
45 views

Equations for coordinates of solar system objects

I would like to write a program that visualizes the solar system. To do this, I would need equations for calculating the coordinates of each solar system object at a given time. Where could I obtain ...
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2answers
111 views

How did water get on Earth

I recently read that water more then likely got here by comets (carrying water) hitting the Earth. However it also it says the impact of a comet hitting the Earth is much greater then an atomic bomb. ...
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3answers
114 views

Do we still use the term “astronomical unit” nowadays?

An astronomical unit is defined as the measurement of distance between Earth and our Sun, my question is since distances between celestial objects beyond our solar system are vast and unimaginable ...
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2answers
111 views

How dense would planet earth have to be to have the same gravity as Jupiter?

I was reading this question about how small could a planet be while having earth-like gravitational pull. This got me thinking, how dense would planet Earth have ...
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2answers
114 views

Precessing of the Earth

It's been known that the Earth's axial tilt varies from 22.5 to 24.5. Does this result in a wobbling while the value of the tilt varies about these two limits? If so, how does it affect the mechanics ...
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2answers
123 views

earth is spherical , does it mean the ground on earth is like a ball? [closed]

I know earth is spherical in shape. Does this means earths atmosphere is spherical in shape or the ground/(land+water combined) is in spherical shape. I have some doubts if the second is true. ...
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2answers
82 views

Meteorites bring water

The latest information suggests that Earth's water came from Meteorites . The Moon was also bombarded by Meteorites and yet it has no water. Is this because it lacks an atmosphere and its water was ...
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2answers
152 views

Tide on the Moon

If the Earth's Moon had a water ocean of depth 2-4 Km, how high would the tides rise due to the Earth's gravity? (Just a hypothetical question.)
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2answers
91 views

Near-future astronomic events that could threaten Earth

What kinds of astronomical events can pose a serious threat to life on Earth in the near future (1000-10,000 years). If there are none in the near future, when is the soonest event that is predicted ...
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1answer
183 views

As days get longer, why isn't the added daylight split evenly between sunrise and sunset?

I have a basic understanding of the sinusoidal relationship of the rate of change of daylight as the year goes on. But it seems intuitive that the changes should be equally split between sunrise and ...
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6answers
2k views

Why doesn't Earth's axis change during the year?

My understanding is that the Earth's axis points in the same direction in space during its entire orbit around the sun. And this is what causes our seasons. My question is why doesn't the axis follow ...
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1answer
40 views

What is the boundary in the atmosphere seen in this video?

This video, which shows time-lapse views of Earth from the ISS, consistently shows some sort of hard boundary in the atmosphere, below which there seems to be significant reflection from sunlight ...
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3answers
3k views

Does the Earth have another moon?

I was just wondering what are the chances that there is a small object (say less than 1 km but more than few meters) that orbits the Earth but has remained undetected by us? Are we actually ...
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1answer
171 views

Look up current positions and velocities of solar system objects

I am working on an orbital dynamics code and, for fun, I would like to model the Sun-Earth-Moon system with my code. I can look up the masses of each object just fine, as well as average distances ...
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2answers
162 views

What is the orbit of Earth around the Sun?

According to wikipedia and other sources, a planet and a star always move in a circular orbit around the common center of mass of the both bodies, in case of Earth and sun, this center of mass lies ...
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1answer
220 views

Distance between Earth and where The Big Bang's happened? [duplicate]

The universe is around 13.8 billion years old. We know how fast the light is. We also know how fast our galaxy moving around inside observable universe. Is it possible to calculating distance ...
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2answers
130 views

Could the Philae comet lander be recharged by laser?

Could the Philae comet lander be recharged with a laser (or possibly many lasers) from earth? My thought would be to aim one or more powerful lasers from earth at the Philae lander to recharge it ...
4
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1answer
2k views

How bright is the full Earth during the lunar midnight?

At lunar midnight (i.e. the new moon as seen from Earth), the Earth is in its full phase with its entire disk in sunlight, and it is the brightest object in the lunar sky. How bright is it, and how ...
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2answers
1k views

Can you see man-made lights on the dark side of the Earth from the surface of the moon with the naked eye?

This question is prompted from a comment on this answer: Could a person on the surface of the moon see man-made lights on the dark side of the Earth with the naked eye? If not, how much magnification ...
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1answer
89 views

How does this strategy for chasing the sunset work?

In Randall Munroe's What If? blog he tackles this question: What is the longest possible sunset you can experience while driving, assuming we are obeying the speed limit and driving on paved ...
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1answer
89 views

Why does Earth enjoy a significantly longer time as a habitable planet as compared to Mars or Venus? [closed]

On a related note, why didn't Venus remain habitable for longer than it did? Is the current hypothesis as to the time when Venus's atmosphere became hostile and what event triggered it, proven true?
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2answers
1k views

Will Earth lose the Moon before the Sun goes into supernova?

Ive read on some sites and saw on youtube videos that the moon is getting away from earth by 1-3 cm a year. Is this enough to make the Earth lose the Moon before the Sun goes into Supernova? Im ...
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1answer
191 views

From what distance can one object influence gravity of another object?

Each object in the universe has its own gravitational influence on all other objects in the universe. What distance do they have to be from each other to create only one gravitational influence? ...
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1answer
123 views

Why does this graph for sunlight intensity on land has a steeper slope during sunrise as compared to sunset?

I got this image while checking weather data for a city in North India using Mathematica's Wolfram Alpha query I noticed one feature in the graph which i could not explain . Why does the encircled ...
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1answer
111 views

What causes the bright white area in this photo of the earth?

Regarding the photo of the earth described here, I know that the green tinge on the left hand side is to do with the aurora borealis. What's causing the bright white light on the right hand side?
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3answers
182 views

I know when the human history ends. Or not?

If you think that we born on 1920...2000 and knows that the sun will explode 4 to 5 billion years from now. you will say that the time is a strange thing. I can not say that i will die before i know ...
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2answers
94 views

Birthdate differences calculation relative to earths orbit duration

I have got a question as i am trying to figure out what the real difference between the birthdate of my friend and me is. I am born on 1983 6th February 7 am. My Friend is born on 1984 7th February 1 ...
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1answer
54 views

the length of second, minute or hour, what defines the time of exo planetary bodies

we measure time based on earth and earth mass\gravity plays a role in the measurement ? so how and what would be time if not earth time on other exo planets since they will be having different ...
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2answers
277 views

Is it possible for a person to not see the new moon at different places on earth?

It is known that theoretically we see the same moon phase everywhere on the earth, but practically I see that people are unable to observe the 0.8% waxing crescent at different places on earth. This ...
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3answers
274 views

Inclination of planets

Why do the planets have roughly the same inclination with respect to Earth? Looking at the inclinations, which I got from http://www.astronomynotes.com/tables/tablesb.htm , we see that Mercury has ...
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2answers
116 views

seasons elongating and shortening

I have heard of years with longer summers and winters and shorter springs and falls and vice versa because of a change in the earths axis. Is this from the procession that causes the season switch ...