Questions tagged [planet]

Questions on astronomical objects orbiting a star massive enough to be rounded, not massive enough to cause fusion, and which have cleared its orbit of planetesimals.

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3 votes
2 answers
368 views

Was Theia a planet or an asteroid?

According to an article Theia was an asteroid and according to The Wikipedia article about Theia Theia was an Earth trojan (which is an asteroid). Which is dubious, so why it is dubious?. It feels ...
2 votes
1 answer
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Is Uranus the farthest object in Solar System that you can see with naked eyes?

The following text is from this article: The fact is, even at its brightest, Uranus is still quite faint. It’s barely perceptible as a dim speck of light to the unaided eye, even under dark skies. At ...
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How many planets can be seen by the naked eye? [closed]

I can see Venus and Mars, what about the others?
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Do planets affect their stars beyond causing them to wobble?

Are there any situations in which the existence of a planet measurably affects its star, aside from orbital wobble? I am curious about possible ongoing affects, not stuff that happened during stellar ...
2 votes
2 answers
135 views

How would solar and lunar eclipses differ if the moon was replaced by every planet in our solar system?

A solar eclipse on Earth lasts only around 7 minutes and some of them can be total, annular, partial, or hybrid. The moon's shadow on earth is small compared to the Earth's shadow on the moon. Usually,...
6 votes
5 answers
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What is the likelyhood that planet X is a glass (not a typo for gas) planet? What would it mean if it were for what we know of astronomy?

Scientists have been looking for an explanation for the unusual orbits of extreme trans-neptunian objects. One of the possible explanations some astrophysicists have come up with was the possibility ...
6 votes
1 answer
143 views

How diverse are chemical reactions outside Earth?

Chemical reactions we are used to here on Earth are hardly possible in most of interstellar space due to extremely low temperature and density (though some pretty complex molecules are found there, ...
0 votes
0 answers
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What is the minimum strength of a magnetosphere needed to sustain life?

On Earth, the magnetic field intensity is roughly between 25,000 - 65,000 nT. Assume for a second that we have a planet with double the atmospheric thickness of Earth but with a similar composition. ...
6 votes
1 answer
151 views

Stars being eclipsed by planets

I would like to figure out if any of the solar system planets have ever eclipsed a particular star (i.e. crossed the line of sight from Earth to the star) or will eclipse it in the future. Is that ...
1 vote
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Tables or software for some astronomical data

Recently I saw a beautiful (but not rare) phenomenon - Jupiter was "directly above" the Moon, that is, they had the same azimuth and a small difference in altitude. I would like to see on ...
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5 votes
1 answer
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Does the orbital velocity of a planet affect its escape velocity from the planet surfaces?

I'm trying to write a hard sci-fi novel with good accuracy, but when it comes to astronomy, I'm a total amateur. Here's my fictional planet that orbit a black hole information: Star Mass = 10000 Solar ...
-1 votes
1 answer
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Is it possible for us to have mistaken a few brown dwarfs and a few white dwarfs for a burning ethane-octane-oxygen planet?

Is it possible that we humans may have missclassified a handful few but not all brown dwarf stars or white dwarfs, when there really could be possibly a burning planet? Assuming a large enough planet ...
1 vote
0 answers
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If a planet orbits an M-Star in an S-type orbit around a G star, what is the minimum distance from the G star that it could remain tidally locked?

I'm wondering how close a planet-M-dwarf system could orbit a G star and have the planet remain tidally locked to the M star. I'm curious, because I'm designing a habitable planet, and I want the ...
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2 answers
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How many undiscovered planets might be in our solar system?

Some people talk about the possibility of a planet 9. Could there be a planet 10 or 11? How many undiscovered planets could there be in our solar system?
3 votes
2 answers
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Could a planet have a massive crater without collapsing due to gravity / other factors?

A severely destroyed planet is a popular trope in media. Here are a few examples from fiction with pictures (spoiler warning). A crater with a diameter 1/3rd the size of the planet itself: Earth (...
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In which Indian Institutions can I find Planetary Scientists or Planetary Geologists? [closed]

Which institutions in India provide labs and facilities for research in the field of Planetary Sciences/Planetary Geology?
3 votes
2 answers
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Could a planet theoretically have a stable orbit between Venus and Earth OR Earth and Mars

Take a planet, identical to Earth in size, mass, gravity, rotation, etc.(but without the moon). Could this planet theoretically maintain a stable orbit for many hundreds of millions of years orbiting ...
4 votes
1 answer
241 views

How would you calculate the "day" on a planet orbiting a red dwarf that is a companion to a larger star?

So the idea is you have an Earth-sized planet with a moon orbiting an M-class star (let's give it .25 solar masses) at 0.2 AU, with an orbital period of 63 days and a 24-hour day. Its orbit has an ...
1 vote
1 answer
77 views

What parameters can we obtain from imagery of planets?

Looking at images for the planets of the solar system in all different wavelengths, I was wondering whether we can deduce any information about the planet itself without using anything other than an ...
2 votes
0 answers
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How long would it take for a planet captured by a red dwarf to become tidally-locked if it started out rotating retrograde?

So say for the sake of argument that we have a red dwarf orbiting a G of K-class star. An Earth-sized planet forms, maybe at one of the dwarf star's Lagrange points to its primary, and eventually ...
6 votes
1 answer
57 views

Does a more massive main proto-body result in more massive satellites? More satellites?

Suppose that we have a forming protostar and an accompanying protoplanetary disk. Does the mass of the protostar have any direct relation to the masses of resulting planets or amount of resulting ...
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How to calculate absolute magnitude of planets?

Knowing: Star's radius $r_s$ , luminosity $L_s$, and absolute magnitude $V$ Planet's radius $r_p$ , albedo $a$ , and distance $d_s$ How can you calculate the absolute magnitude of a planet in a ...
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7 votes
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Why do the Sun and gas planets rotate faster at equator than at poles?

From this site, it states that: The Sun spins faster at its equator than at its poles. I have also read somewhere that the gas giants (gaseous planets like Jupiter, Saturn, Uranus, and Neptune) also ...
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2 votes
1 answer
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Does interplanetary magnetic field interact with the planet's own magnetic field?

The Wikipedia states on the page about the Interplanetary magnetic field that The interplanetary magnetic field (IMF), now more commonly referred to as the heliospheric magnetic field, is the ...
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3 votes
1 answer
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If you were standing on a habitable moon of a gas giant, what would the planet look like during the day vs the night? [closed]

If you were standing on the proplanetary side of a habitable moon of a gas giant, and the moon had a thick enough atmosphere to make the sky blue, how would the gas giant look during the day? Would it ...
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2 votes
0 answers
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What is the maximum size for a solid celestial body such that it still can be tunneled down to the core?

Old science fiction had lots of stories that involved people exploring the center of Earth, like for example Journey to the Center of the Earth, by Jules Verne. As Earth sciences advanced, this sort ...
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1 answer
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Are gas planets in hydrostatic equilibrium?

Why don't gas planets get bigger and smaller over time? Are their sizes constant? Are they in hydrostatic equilibrium like the Sun? Is there an internal force against gravity that does not allow ...
2 votes
1 answer
230 views

Have there been any searches for extraterrestrial life which doesn't require water, oxygen and carbon?

This is question is similar to this, but that question has already been voted to be closed. I will add though that I joined this website today, so I am still learning how to write a good question here....
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1 answer
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Life forms on planets not requiring water and oxygen as basic building blocks [closed]

When scientists explore other planets such as Mars, they look for life derived from water and oxygen (correct me if I am wrong) with a purpose to see whether that planet is habitable for humans or not....
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4 votes
2 answers
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Which world did Carl Sagan know of with a million moons?

I recently read Carl Sagan's The Cosmic Connection. In it, he begins the seventh chapter with a series of claims to depict the universe as "vast and awesome." I'm particularly interested in ...
5 votes
1 answer
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What kinds of stars have viable habitable zones other than G-type stars, and what would life be like orbiting them? [closed]

What would foliage, landscape, and quality of life on dwarf stars and blue stars? Would it be possible for a human to live without high-tech devices and such?
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1 answer
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Binoculars 10x50 in light polluted place

I think to buy cheap 10x50 binoculars for astronomy observations. My leaving area is light polluted, I can see only bright stars and planets in naked eye. Will I can with this binoculars observe ...
8 votes
3 answers
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Planets looks like normal stars when I see them using telescope

I've been trying to see planets using my 114 mm (aperture) f=900 mm telescope. For the moon, I got very good quality pictures, but when I try to see planets they just appear to be as if I'm looking at ...
0 votes
1 answer
124 views

Would an accumulation of dust in a planet's L1 Lagrange point plausibly obscure it from Earth?

I'm designing a hypothetical newly discovered planet in our solar system that has an ecosystem comparable to Earth's that supports intelligent life. The explanation given for the planet remaining ...
1 vote
3 answers
863 views

Is there a Lagrange point between the earth and the moon?

Is there a Lagrange point between the earth and moon where a space station could sit forever without orbiting around either? Just curious, but it seems like a place like that would be perfect for ...
3 votes
1 answer
89 views

What are the time periods of precession of equinoxes of other planets?

Earth has a time period of 26000 years approximately for precession of its equinoxes. What are the time periods of precession of equinoxes of other planets?
4 votes
3 answers
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Why do most dwarf planets have mass comparable to moon?

It was quite interesting to spot that most dwarf planets have masses close to that of our moon (if we let an error to fluctuate within two orders of magnitude). Why it is so? Is there any common ...
5 votes
1 answer
111 views

If the Earth became tidally locked with the moon, would that last forever?

If the Earth and the moon became tidally locked, would this last theoretically forever (assuming no external gravitational force modifies their orbits, for example, ignoring the effects caused by the ...
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8 votes
1 answer
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How am I supposed to locate the planets Uranus and Neptune with a 70 mm f/5.7 refractor?

I can locate all of the planets other than Uranus and Neptune. This is mainly because they are very dim and I live where there is just enough light pollution so that I can't spot them. I have a Gysker ...
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3 votes
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Why aren't there sulfuric acid seas on Venus?

It's commonly known that sulfuric acid rain doesn't reach Venus' surface. It evaporates instead because the surface it too hot. But considering how high the pressure at the surface (9.3 MPa), shouldn'...
1 vote
2 answers
172 views

Could a magnetosphere be created for Venus by recreated by spinning-up the planet to a 24 hour day?

If Venus in it is current state, started rotating at the same rate as Earths 24hrs rotation, would it develop a magnetic field of roughly the same strength as Earth's? If so, would that help in any ...
17 votes
3 answers
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If planets are ellipsoids why don't we have 3 diameters?

We know that each ellipsoid has 3 diameters named $2a$, $2b$, and $2c$. The Earth and all planets, in general, are ellipsoids (Saturn is the best example because it's the most oblate planet in the ...
4 votes
3 answers
259 views

How do rocky planet break up? Would they fragment into "a gazillion" rocky pieces pieces, or crack open like an egg?

I remember seeing a movie (probably star wars) where this bad guy (Darth Vader) shoots a superb laser (Death star) to obliterate a populated planet, Alderaan (how inhumane). The problem is, the planet ...
12 votes
1 answer
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Daylight hours on Titan?

I still cannot seem to wrap my head around Titan's day and night based off of math. From what I understand, Titan has a day of 16 earth days (384 hours) in which it circles Saturn once (its day and ...
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4 votes
1 answer
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Accurate formula for calculating the mass of an exoplanet using the transit method

A friend and I did some work on exoplanets with the help of a research institute (IEEC in Spain) for a major high school project. What we did was to "redetect" the exoplanet XO-6b through ...
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1 vote
2 answers
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Planet's distance data from JPL Horizons - Mars Curiosity mission

I am looking for distance measurement in AU between planets and Earth. E.g. For Mars, Current distance, or distance of Mars from Earth at any given datetime, along with minimum (closest approach), ...
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1 answer
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Can a destroyed earth reform into another habitable planet?

Let's say a planet-sized object collide with earth, disintegrate it, then reform at the same orbit as earth. Will it eventually formed into a habitable, life-supporting planet with living organism?
0 votes
1 answer
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What would the temperature be on the surface of Sirius B [closed]

If Sirius B was a planet like Earth and not a white dwarf star what would the temperature be on the surface of Sirius B at its nearest and furthest distance? 8.2 AU to 31.5 AU EDIT: I want to know if ...
-2 votes
1 answer
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Is it possible that Planet 9 was thrown out of the Solar System? [duplicate]

Is it possible that this planet changed other planet orbits (from which we assume that it exists) but then was thrown out of the Solar System in past when Sun was close to some other star? And it ...
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1 answer
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Earth-Mars-Moon or No Moon Barycenter Orbit Possible?

Could an object of sufficient mass deflect Mars so that it ends up stably orbiting an Earth-Mars-Moon barycenter? What would the distances eventually become between each orbiting body? What if the ...

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