Questions tagged [earth-like-planet]

Questions about solar system planets/moons and exoplanets that exhibit similar features to the Earth.

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How much of the earth would remain intact if the sun expanded into a red giant encompassing its orbit?

It seems to me that part of the earth might survive being absorbed by a red giant. How long would it take the heat, plasma, magnetic field, etc. of the sun to eat away at the earth? How long could it ...
2 votes
0 answers
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Can distribution of stars / planets formation be a long-tailed one?

We know that peak of star formation already passed 10.1146/annurev-astro-032620-021910 and it looks like peak of planet formation occurred slightly after formation of Earth 10.1017/S1473550415000208 ...
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Crust thick enough to prevent volcanos

Could you have an Earth-like planet with a crust thick enough to prevent volcanos from forming?
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Did we adapt to Earth or Earth to us? [closed]

I often hear that Earth is a unique planet because it has life. We also see a proper balance between plants and humans and other animals. Why is life not possible on another planet? Often people say ...
18 votes
1 answer
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Exoplanet dip in transit light curve when the planet passes behind the star

In the animation below, I don't understand why the brightness slightly decreases when the planet is behind the star. Where does this effect come from?
20 votes
1 answer
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Why are most discovered exoplanets heavier than Earth?

Looking at all discovered exoplanets (4393 exoplanets), I found than only 17 of them (less than one percent!) have masses less or equal to Earth's mass. Why so? Is it because it is very difficult to ...
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For colonization purposes, what is so good about Titan? [closed]

I have read that Titan is the best candidate for humans to colonize in our Solar System. However it has no water, it's atmosphere is not breathable and it is -290° F on the surface. It doesn't sound ...
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1 answer
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How would Earth's magnetic field change if the outer core was solid?

A widely accepted theory for how the Earth's magnetic field is generated is the dynamo theory. Dynamo theory describes how molten magma convection currents containing metal are locally spun the same ...
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17 votes
3 answers
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Do celestial objects need to be big to have liquid water on their surfaces?

I mean no asteroid, planetoid that I am aware of has water on its surface. It is way more common to see ice in it. So I figured that the size of the celestial body has something to do with the cycle ...
7 votes
1 answer
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How many quakes have been detected by InSight?

Insight has been on Mars with its seismometer for almost two years now. Has it detected any mars-quakes yet? How often do these quakes seem to occur? Is there a website where the current number of ...
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1 answer
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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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Can a planet exist with the same mass as the earth, but have a different diameter?

Can there be a planet with the same mass, and a similar composition, as the earth, but with a larger or smaller diameter, and how could that theoretically occur? I've tried to see if there is any ...
2 votes
1 answer
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Could an Earth-like magnetic field protect life at exoplanet Proxima Centauri b?

I took a look at Wikipedia's page for Proxima Centauri b, the exoplanet that orbits Proxima Centauri, where it is said it is expected to receive 2000 times of stellar wind pressures than on Earth. It ...
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2 votes
1 answer
94 views

How would one figure out the rate of axial precession of a planet?

I want to start with the fact that I am by no means an astronomer, or even a hobbyist in the field. I am attempting to build a fantasy world which still reflects accepted physical laws. My problem ...
3 votes
3 answers
154 views

Is there a far away probe that has recorded the light spectrum from Earth as if it were an exoplanet?

We analyze the light spectrum of stars and distant planets to know characteristics like: chemical composition, temperature, mass, etc. Starting from the same principle, a probe at the border of the ...
2 votes
0 answers
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Are circumbinary and noncircumbinary habitable zones mutually exclusive?

Could a binary star system have an earth-like planet orbiting star A, a second earth-like planet orbiting star B, AND a third earth-like planet in a stable circumbinary orbit? Or does the space that ...
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6 votes
1 answer
427 views

Why Venus evolved so differently from Earth?

I read somewhere that the reason why Venus has a runaway greenhouse effect and Earth doesn't is the former's inability to form separate tectonic plates due to slightly higher temperature softening the ...
5 votes
3 answers
260 views

Could a moon orbit an Earth size planet in such a way as to create a solar eclipse lasting for several weeks from start to finish?

Is it theoretically possible for a moon to orbit a planet (let us say Earth size, mass and solar distance) in such a way as to create a planet-wide solar eclipse lasting several weeks? These are my ...
0 votes
1 answer
153 views

What’s the closest earth like planet we have discovered in our galaxy? [closed]

What’s the closest earth like planet or moon to earth we have discovered in our galaxy?
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What is the smallest possible planet with same sea level atmospheric pressure as Earth? [closed]

Suppose there is a planet made of pure tungsten (a quite common and heavy element), with perfect spherical shape. Which should be its radius so that the air pressure and ground/sea level is the same ...
3 votes
1 answer
716 views

Could Planet Nine be a tiny black hole or an exotic compact object such that it escaped detection? What would its bounds be?

Planet Nine (a variant of the old X-Planet and Tyche-Thelistos hypothesis) proposes a super-earth planet at the edges of the solar system with a mass of around ten Earths. However, given the interest ...
1 vote
1 answer
135 views

What types of star do we know are hostile to life (like ours)?

Certainly all stars have enough energy for a planet to host life. But a more magnetically active star is not preferred because solar ejection could strip planets of their atmosphere. What's the right ...
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3 answers
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Can life on earth be supported by only a Red Dwarf star or a White Dwarf(state still hot not cooled enough yet)?(Provided it is near to the star)

Can a red dwarf star or a white dwarf have enough energy to support life on earth? How it will change the climate and the seasons of earth if it is our only star? (energy source)(Expecting it to ...
5 votes
2 answers
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Trisolar syzygy and it's effects on the planet

Slightly spoilers here, but in the novel The Three-Body Problem, there's a scene in which Civilization #184 is destroyed by the stacked gravitational attraction of the planet's (aptly named Trisolaris)...
6 votes
2 answers
199 views

horseshoe orbits

I'm designing a moon system for a fictional setting, and recently came across the idea of horseshoe orbits. The gist of my question is how many objects can share a horseshoe orbital at a time? I ...
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Is there another habitable planet in our galaxy? [closed]

I have wondered, what'll happen when we destroy our planet or it becomes uninhabitable for human life? Is there another option than the complete extinction of the human race? Can anyone give me a ...
2 votes
0 answers
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Predicting Temperature Variation on Planets with High Eccentricity or Long Diurnal Periods

Whew! That title was a mouth-full, but accurate I hope. What I'm trying to figure out is a model for calculating the approximate temperature variation for a generally earth-like planet (similar ...
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Would blocking sunlight on Venus help make it habitable? [closed]

Lets say we had the technology to create a mini-Dyson structure, like a shutter style curtain between the Sun and Venus, blocking the sunlight in a controllable manner to cool down it's temperature. ...
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What if we are looking for the wrong signs of life on other planets?

I am by no means an astronomy expert, having only taken 2 semesters in college. But I am an avid follower of news reports that look for signs of life on other planets. Today it was announced that 20 ...
2 votes
1 answer
130 views

Could a binary system of two planets with oceans reflect each other?

If there were two earth-like planets in a binary system and one of them had landmasses, and the other one had oceans covering a significant amount of its surface, could you see the continents of the ...
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What of the following moon-situations would be better?

Okay, so imagine that there is an Earth-like planet, with the following conditions: It's further from it's sun than the Earth is from the Sun (not much, but enough for weather to be a little colder ...
1 vote
1 answer
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If I had a horseshoe orbit of two moons...

Consider an Earth-like planet, with two moons. I guess the two moons would have to be smaller than our own, for the system to be stable. Is that stable? I did some research, and apparently Janus and ...
4 votes
1 answer
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Wondering about a horseshoe orbit

Since I'm not a physicist, I want to know how that system works. For instance, if there was a planet, very similar to the Earth, but with two moons, and the moons where in a horseshoe orbit, how does ...
1 vote
1 answer
120 views

What apparent sizes of the sun an Earth like planet can have?

What is the smallest and largest sun an Earth like planet could have in its sky? What kinds of stars are those? I saw this video and thought, yeah, some of those stars are really big in absolute ...
29 votes
1 answer
4k views

Can a tectonically inactive planet retain a long-term atmosphere?

Can a planet be tectonically inactive and still retain a magnetosphere and protected atmosphere? How does that work? How else could a planet retain a thick atmosphere like Earth's for extensive ...
1 vote
1 answer
5k views

Calculate planet's surface temperature by distance from star [duplicate]

If the planet and star in question are very similar to the Earth and the Sun, how can I calculate the planet's surface temperature by knowing the distance from the star? This question was originally ...
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3 votes
2 answers
655 views

Could this three moons system be stable?

In my fictional world I have selected all parameters to maximize the Hills Sphere of my planet. The planet has three times Earth's mass and it is located in 2 AU from its star that's 1.4 times more ...
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Are there any common characteristics of habitable planets?

Recently, over a thousand exoplanets were confirmed in one huge sweep which is a huge achievement and in the mix a dozen or so possibly habitable planets were confirmed as well. This made me wonder, ...
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4 votes
1 answer
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Sun as our Supergiant

Let's talk about the time when our sun becomes a supergiant. We know that our solar system may get destroyed or it may get affected due the large mass of the supergiant and also due to the large ...
18 votes
2 answers
3k views

How many planets have we discovered that can support human life?

I have heard a lot of buzz about distant planets that could potentially be second homes for human existence, but what is that approximate number?
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How small a star can provide Sun-level illumination to its planets?

...or how small can a solar system be, to sustain an Earth-like planet? Sun is not really small, and 1AU is pretty far when you look at orbital radii of exoplanets and size of their stars. How small ...
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1 vote
3 answers
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Does more ocean on an Earth analog produce a different rotation period?

Would an exoplanet that has more ocean than Earth rotate at a different speed as a result of this? Would the amount of water impact the weight, gravitational pull, and/or tidal forces and cause a ...
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6 votes
1 answer
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How did pre-Earth's mass and orbit change at the Moon formation event?

The popular, but still disputable, Moon formation theory is that a pre-Earth was hit by a Mars sized planet. The mass ratio of Earth:Mars:Moon is roughly 100:10:1. Does this mean that pre-Earth was ...
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Why is the Earthian atmosphere 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 as ...
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1 answer
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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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Could we detect an earth-like planet around another star?

Could we detect an earth-like planet (e.g. similar distance from star, and similar size) with current planet finding techniques? If an earth-like planet were orbiting our nearest star, excluding the ...
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1 answer
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Collision of two Earths

Assume that two Earth-like planets orbited the same star, with elliptic orbits. Eventually, something occurs that caused the two planets to collide. What would be the outcome of such a catastrophe? ...
6 votes
1 answer
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How should exoplanet discoveries affect SETI?

Given that SETI was created before the discovery of exoplanets, has this changed how they search? Would it make more sense to focus efforts on discovered earth like exoplanets?
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Why is carbon so rare on the Moon and on Mars?

Carbon is the fourth most common element in the universe and in the Solar system. It is about the ninth most common element in Earth's crust. It doesn't seem to be part of any of the ten most common ...
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4 votes
1 answer
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What would be the dynamics of a double-planet system, similar to Earth / Moon, but with both bodies nearly Earth-sized?

Researching a sci-fi story involving a "twin-planet" system. Is such an arrangement (however unlikely) physically possible? And if so, must they be tidally locked with each other, similar to the moon, ...