Celestial body that orbits following an elliptical path around a star or stellar remnant.

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2answers
56 views

What should we do If we wanted to increase the angular velocity of a planet? [duplicate]

We could hit it with really fast objects, but could we manipulate the orbit of a large satellite to speed up its rotation? What would be the easiest way?
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0answers
21 views

How to find the nature of an orbit knowing 2 altitudes and the time interval? [on hold]

A body was observed at an altitude of $366 km$ and then at $633 km$, after $12.5$ minutes. Angular separation between the 2 measurements is 45 degrees: find nature of orbit and true anomalies at 2 ...
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0answers
37 views

Explaining why planets are round [duplicate]

is it possible to prove that planets (and/or stars) are always round (elliptical if you consider the spin)? Is there a set of equation that demonstrate that fluids (after all, molten rocks "floating" ...
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1answer
21 views

Inclination of planets

What is the inclination of each planet with the equator of the Sun? Doesn't this have a relationship with the eccentricity of the planet's orbit?
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1answer
73 views

Does spacetime have symmetric curvature around an object? If yes, then why do planets revolve around the Sun in elliptical orbits?

Does spacetime have symmetric curvature around an object? If yes, then why do planets revolve around the Sun in elliptical (as opposed to circular) orbits?
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0answers
28 views

Has science yet assigned a machine type/classification regarding planets?

Considering our Sun/stars (on the most basic terms) have often been referred to as a hydrogen fusion engines/machines... what type/class of engine/machine have scientists actually assigned to planets, ...
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1answer
45 views

The stronger the gravity, the faster an object will fall? [closed]

On a planet with gravitation ten times stronger than that of Earth's, will an object fall faster? Let's suppose that there are two planets; Roddo and Earth, respectively. Roddo has ten times the ...
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3answers
61 views
1
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1answer
54 views

How do you calculate density if you also account for gravity?

Consider this. I have an Earth-sized quantity of water that I throw into space. Naturally, it will assume the shape of a ball. Now hear me out. Density's definition generally assumes that it will ...
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1answer
66 views

How does the Earth rotate, given that the torque acting on it while revolving is zero?

I've come to understand that the torque acting on the Earth while revolving the Earth is zero. Torque is the force responsible for rotation of a body. So how does the Earth rotate?
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1answer
69 views

How dense and compact would Kepler-5b need to be to become a black hole

How dense and compact does Kepler-5b need to be to become a black hole ?
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6answers
4k views

If the gravity at the center of the Earth is zero, why are heavy elements like iron there?

If gravity is zero at the center of the earth, why is there a core of heavy elements, such as iron? Alternate question for the opposite hypothesis: If gravity is greatest at the center of the ...
10
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2answers
1k views

How can a gas giant be about the same size but six times more massive than Jupiter?

I've just read this article: http://www.sci-news.com/astronomy/science-kepler-432b-new-super-jupiter-exoplanet-02490.html And I wondered how this could be possible? Maybe it's because this gas giant ...
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2answers
96 views

Why aren't there any clear planets/ stars?

Most gases are clear. So why are there not any planets or stars that are more or less clear in color? I suspect this question may be extremely stupid.
2
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3answers
117 views

Could the sky on a planet theoretically be any color?

The sky on the Earth is blue. Could the color of the sky on a planet with an atmosphere be of any color theoretically? Which colors are the most likely? I think it would be really awesome to have ...
2
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2answers
143 views

Infinity problem: Why is gravity $g=0$ zero at the center of Earth if according to Newton gravity formula $g=GM/R^2$? [duplicate]

It is said that value of $g=0$ at the centre of the Earth. $g$ is calculated using the formula $$ g=G*M/R^2.$$ When $R = 0$, $g$ approaches infinity. I have two ...
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1answer
43 views

Why does a parachute open up faster on Mars than on Earth? [closed]

I recently heard that a parachute opens up much faster on Mars than on Earth. Why is that the case? More specifically, during a NASA Edge TV program, one of the scientists working on parachute tests ...
2
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1answer
23 views

Calculating the size of exoplanets with moons

When astronomers detect an exoplanet using its transit and calculate its size to be, say twice the earths size, do they have any way of knowing that its actually not a slightly smaller planet with a ...
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3answers
117 views

Why are planets in unstable equilibrium in a stable orbit

It is well known that a planet in stable orbit is in unstable equilibrium. If e.g. the moon was just a few m/s slower in velocity, or a few m closer to the earth than it is, the gravity would ...
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1answer
35 views

Are the large moons of Jupiter, Saturn, and Neptune still cooling and does this give and indication of their age?

The core temperatures and the rate at which they emanate heat should correspond to their estimated age. Other forces may create some heat such as the tidal locking that is supposed to be the source of ...
1
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0answers
34 views

Finding the temperature of Earth from temperature of Mars and its distance from Sun [closed]

I am to compute the temperature of planet--in fact I've already found out it's Earth--knowing only: the surface temperature of Mars (210 K) and its distance from Sun (1.524 AU) and of course ...
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votes
2answers
59 views

A Chevy Silverado on Mars [closed]

Another topic that no one seems to consider is driving a 4x4 truck across the surface of Mars, years of experimenting with a robot vehicle when you have 100 years of progress with the motorcar. So ...
3
votes
2answers
62 views

Physics of tidal locking: can the process be underdamped?

Is it possible for a satellite undergoing the process to overshoot the required rotation rate for tidal locking? For example, if its rotation rate is being slowed, can it become slower than it needs ...
2
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0answers
56 views

Protoplanetary disks, angular momentum and prograde orbits

So you've got a protoplanetary disk and you're going to gravitate yourself some planets together. The disk is made up of the usual planetary system stuff, dust and gas and whatnot, orbiting a common ...
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1answer
48 views

How have the duration of the martian day changed in the past?

There is a panspermia theory which claims that life might have begun on Mars and I currently read a post that the human circadian rhythm is closer to the martian day length (about 25h) than the day ...
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1answer
127 views

Could this planetary superalignment happen?

Here's the 'superalignment' I'm referring to: We've all heard the stories about 'mystical planetary alignments' that will increase/decrease the effective surface gravity experienced on Earth (one ...
6
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3answers
757 views

Does the Earth actually rotate around the sun? [duplicate]

Why does one say that the Earth rotates around the sun? There should be no preferred reference frame and from an observer on the sun, the sun will rotate around the Earth.
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1answer
51 views

How do I calculate the right ascension of the points along the ecliptic at given elevations?

How do I calculate the right ascension of the point along the ecliptic nearest the sun at sunset and sunrise that is at a given altitude/elevation? For example, I'd like to compute the right ...
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2answers
37 views

Angular Momentum conservation in star system

This question is related to what happens to a planetary body(like earth) when the star it is orbiting collapses under its own gravity. Suppose a star is rotating about its axis with some angular ...
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1answer
80 views

Gravity on and inside a planet-sized bi-lobed body

Admittedly, for yet another science-fiction project Say I have a planet-like body shaped like a sphere with a torus subtracted out of it, leaving a sort of "apple core" shape. Firstly, is the ...
2
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1answer
67 views

Tidal locking of a planet to a satellite

As in the case of Pluto and its moon Charon, both the bodies are tidally locked to each other, will the Earth ever be tidally locked to the Moon? Is there any effect on the rotation of the Earth ...
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2answers
86 views

Initial Velocity For Orbital (Gravity) Slingshot At Hit Moving Target

In this problem we have three masses, Mass A is on the left side of the sun Mass B is the sun, and Mass C is on the right side of the sun. I want to calculate the initial velocity of Mass A to hit ...
2
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2answers
190 views

Calculate Initial Velocity For Orbital (Gravity) Slingshot

I am trying to find the initial velocity to slingshot a planet around the sun and through a gap. The green ball is the planet, and the yellow ball is the sun. In this trial I need to get the ...
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0answers
76 views

Is it possible that me and my sister saw the outer planets moon-sized from a flying aeroplane? [closed]

I've always remembered this incident, but only recently confirmed that my sister saw it too. We were flying from singapore to australia, but keep in mind that i was 6 and my sister 9 years old.(18 ...
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1answer
34 views

How the earth's internal heat exists

How the earth's internal heat exists? Is it available from it's creation as collation heat? Or is there any other source feeding the heat to the core?
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3answers
2k views

Why do the storms of Jupiter have long life unlike that of Earth?

Recently I saw How the Universe Works. In one of the episodes, concerning Jupiter, they told that the storms on Jupiter can survive many, many, times longer than those on Earth. What is the reason ...
2
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0answers
113 views

What would the collision between a (large) solid planet and a gas giant be like?

Assuming a Jupiter-like planet and an Earth-like planet (Except, say... half the mass of Jupiter), what would happen when the two collide? For clarification: What would the actual collision be like? ...
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1answer
137 views

Is it possible for a solar system to have planets orbiting the star(s) in a spherical pattern?

By the question I mean that the planets spin in their ellipse but all ellipses describe the surface of a near-sphere shape around a star. Same question but for a solar system with 2 stars of ...
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0answers
49 views

Planetary Motion [closed]

L/m = 7.8e10 2E/m = 0. Probe is near earth. I checked eccentricity and it is 1--so we know it is a parabola. As such, how do I find when it is closest to earth? I only know how to do this with ...
2
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1answer
66 views

Help understanding centre of mass

So basically the question I posed myself a few days ago was for a torus shaped planet, what would the gravitational field be like inside the torus? After viewing some answers on the internet, (Gravity ...
3
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2answers
185 views

What is the cause of planetary rotation. Not orbital rotation [closed]

I am a senior in high school, sixteen years old. I think differently than most in my class. Recently, I have been thinking about alternative causes for the rotation of our planets. My current thought ...
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1answer
86 views

How would the solar system change if the Earth were removed

I was reading a closed question with the same title and wondered if it would be on-topic with the following change: Could a large-mass object from interstellar space pass through the inner ...
10
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3answers
925 views

Planets and Pluto? Neptune?

If one of the rules to be a planet is that it needs to clear ALL objects from their orbit, does this also make Neptune a non-planet? Since it has thus far failed to clear Pluto from it's orbit. Or ...
4
votes
1answer
117 views

How big can a cube-shaped planet be? [duplicate]

There can be small cube planets or asteroids, but as they get bigger, the gravitational force compresses them to a sphere. But what is the maximum size?
2
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2answers
97 views

Stability of planet-enclosing shell supported by atmosphere

I understand that a hollow spherical shell of uniform density gives net zero gravitational attraction to objects inside it. So in vacuum, a ball at the centre of a spherical shell would not be stable ...
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1answer
110 views

Planet order in solar system

Why does Mars not follow the logical planet order in space? From small rocky planets to big ones and from big gas planets to small ones?
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0answers
23 views

Numerical tests of Titius–Bode formula for artificial planetary orbits [duplicate]

Titius–Bode law is an empirical formula stating that positions of planets in Solar system is described by: $$a=0.4+0.3 \times 2^m [AU],$$ where $m$ are natural numbers. All planets, with exception ...
2
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1answer
346 views

Presence of planets in Milky Way and other galaxies

Are there only planets in the Milky Way galaxy, or are there other planets in other galaxies? If planets are only in the Milky Way, why aren't there planets in others?
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0answers
87 views

Sedna, VP113 and the likelihood of the PX/Tyche/Thelistos hypotheses

The recent discoveries in exoplanetary science (specially those findings of planets orbiting far far away from its parent star/stars) raise questions about how much we know about the (true, AIU ...
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2answers
254 views

Changes in planetary orbit?

Forgive a novice and her naive curiosity, but I was wondering about planetary orbit and the aging of planets. As a planet ages, does its transit around its sun/star decrease or increase in speed? ...