Planet Definition and 821 Threads

Hi, Forbes just published an article about the Habitable Exoplanet Hunting Project: http://www.forbes.com/sites/jamiecartereurope/2019/11/25/inside-the-247-search-for-another-habitable-planet-within-100-light-years-of-earth/#149fbf103442 I hope you find it interesting! We welcome any type of...

Hello, We hear a lot about gravity-assist, which usually means using a planet like Jupiter to speed a spacecraft on its way to another destination, like Pluto. But what about using a moon of a planet as a reverse gravity-assist? For example, if you wanted to place a spacecraft in orbit...

Homework Statement: Problem: The planet X is far 48 light-years from Earth. Suppose that we want to travel from Earth to planet X in a time no more than 23 years, as reckoned by clocks aboard our spaceship. At what constant speed would we have to travel? How long would the trip take as reckoned...

I was curious about how much we could advance planetary science with the amount we are spending (and planning to spend) on the SLS. Specifically, I want us to increase the number of climates we study from basically Earth to every planet in the solar system. It looks like polar orbiting...

According to MIT Technology Review, the Solar System's conjectured 'ninth planet' might be a Black Hole. https://www.technologyreview.com/s/614441/is-planet-9-actually-a-primordial-black-hole/

So, let's say you have a donut - shaped planet, so a second object can move right on top of the center of mass of the first object. Does force go to infinity? How about potential energy? Or, just take one object, divide it into elements, what happens to the central element of mass within the...

Its velocity, Vp, is towards some other part of the universe, It rotates in the same plane as its direction of travel. The linear velocity of an object on the surface of the planet relative to the centre is Vr. That means the object's total linear velocity is Vp+Vr when it's at one point in its...

Homework Statement: The particle is moving in circular orbit such a way that the net force (F) is always towards the point p (point p is on the circumference of circle). Find the variation of force F with respect to r. i.e find the value of n in the expression F=kr^n Homework Equations: F=kr^n...

So I integrated the work done on the object by both planets. Work1 is until x, and Work2 is from x to d. Where x is the point where both gravitational forces are equal. ##W_1=\int_0^x \frac{GMm}{r^2}dr - \int_0^x \frac{GMm}{(3R+D-r)^2}dr ## ##W_2=\int_x^D \frac{GMm}{(3R+D-r)^2}dr - \int_x^D...

How feasible is such a planet? Can the planet still be dense enough to be rocky and not gaseous?

Summary: I am looking to compile a list of experiments that would be conducted on a new planet to learn about it. Hi, I am trying to compile a list of experiments that would be conducted on a new planet. I'd like to categorize them as such: Simple field experiments that could be done with...

Can someone help me? I am not sure where is my mistake correct answer: ##g=\pi G\rho R## my calculus By symmetry, I only need to add the vertical component of gravity ##dg = \frac {GMdm}{d^2}\cdot cos\theta## (1) Where d=R ##\rho =\frac{dm}{dV} ## ##dm = \rho \cdot dV## (2) (2) in (1) ##dg...

There is a fictional planet with two moons. 1) Is it possible for those two moons to orbit that planet on rotational axes that are different from the planet's rotational axis? 2) If so, can the moons themselves also have different rotational axes?

Does my wrist watch slows down on planet Jupiter? I know Jupiter's gravity is greater than Earth's gravity.

So here is a serious question: If Pluto isn't big enough to be a planet, then wouldn't it be a moon to Sol. I mean, a planet can have a moon. A moon can have a moon. So can a sun have a moon? Is there actually a rule? Inquiring minds want to know.

In a recent thread, @sweet springs asked: I pointed out that the claim about Newton is only strictly true in a uniform gravitational field, and proposed an approximation in GR. The idea was to take a Schwarzschild spacetime, restrict the "acceleration due to gravity" to some specified value, and...

Based on our current understanding of astrophysics, what's the largest possible rocky planet, theoretically speaking, with a surface gravity of 1g? The larger the planet, the lower the average density, and there's a structural lower limit to the density.

I've been doing some thinking on a sci-fi story about a colony around a Red Dwarf Star. I understand that most planets around Red Dwarf Stars, at least in the habitable zone, would be tidally locked. I created another thread to ask about ways to maintain a planetary rotation. My main question...

Given that the gravitational field falls to zero at the centre of a large body (e.g. the earth), what happens to the pressure curve? (Assuming no effects due to high temperature.) Does it ease off too? What would the curve look like and what would the formula be?

I'm having trouble with this simulation I was given by my teacher, any help with how I should go about this?https://www.thephysicsaviary.com/Physics/APPrograms/MassOfPlanet/index.html

<Moderator's note: Yellow press link and headline deleted.> Scientists have theorized that a planet (or planets) may have collided with our sun in the solar systems past...

If a hypothetical planet was once where the asteroid belt is now, and was removed (for example exploded and fell inwards towards the sun where it got burnt up), would this cause the inner planets to migrate outwards into new orbits due to the orbital resonance lost by this hypothetical planet...

Does our solar system host a Ninth planet, If so has our solar system under gone planetary migration?

Homework Statement In a distant galaxy, a planet orbits its sun at a distance of m with a period of 108 s. A second planet orbits the same sun at a distance of m. What is the period of the second planet? Select one: a. s b. s c. s d. s e. Homework Equations T^2=constant * r^3 The...

I recently read a short summary of Kepler 11 and the Kepler Mission. I understand that the orbital period of a planet is a function of its velocity and distance from the star, and the mass of the star will also factor in. Question: Is the mass of the planet also a factor? In other words, does a...

Consider a spherical planet of uniform density ρ. The distance from the planet's center to its surface (i.e., the planet's radius) is R. An object is located a distance R from the center of the planet, where R < Rp. (The object is located inside of the planet.) 1) Find an expression for the...

Homework Statement The change in gravitational potential energy of a mass m as it moves from the surface to a height h above the surface of a planet of mass M and radius R is given by: ΔPE= GMmh/R(R+h) a) show that when h is very small compared to R , this approximates to the more familiar...

I have problem with an A2 physics question: A planet is orbiting a star at an average distance of 10^9 km. The period of its orbit is 500 Earth days. The gravitational constant is 6.67x10^-11 Nm^2kg^2. a) Calculation the mass of the star. b)Explain why you cannot determine the mass of the...

So I'm getting somewhat weird numbers when trying to calculate the solar irradiance at each planet. Starting with a baseline of irradiance at Earth of 1376 W/m^2, I use the inverse square law against distance. I find the values for Mercury and Mars are really off, while Venus & Neptune are...

Homework Statement You are exploring a newly discovered planet. The radius of the planet is 7.20 * 107 m. You suspend a lead weight from the lower end of a light string that is 4.00 m long and has mass 0.0280 kg. You measure that it takes 0.0685 s for a transverse pulse to travel from the...

Homework Statement "Given a certain rocky material, estimate the greatest possible radius of a planet made up of said material" Homework Equations ##P = \frac{2}{3}\pi G\rho^2R^2## ##R = \frac{1}{\rho}\sqrt{\frac{3P}{2\pi G}}## The Attempt at a Solution I'm not quite sure of the validity of...

Forking a subject that was in risk of hi-jacking anther thread here. If the hypothetical TNO "planet 9" is detected , it would not fit the IAU's current criteria of being a planet. What would it be ? For the sake of discussion let's assume 10 Me and estimated likely distance and orbital...

Pardon this possibly information-free post... Since Mike Brown published his papers on the possibility of ~10 Mearth mass body beyond ~200 AU, and it was discussed a lot, I imagine now there is sort of a quiet race among astronomers in TNO field to find this thing. IIUC, Mike has his own team...

Would the shell theorem prevent a binary planet system, with two ideally equal masses, structure etc?

Conventional Wind turbines now have 3 blades. I assume this is a matter of average air pressure. 1)Would a future wind turbine working on Mars with about 1% of Earth’s air pressure need to have many more blades? 2) Would all those Victorian windmills have been any more efficient with 3 sails...

If we have two objects A and B appear on the opposite sides of the equator of a planet like Earth with the same mass as Earth. Object A is a neutron star with the mass of the sun and object B is a iron cube with the mass of one gram. Will A or B hit the Earth at the same time or will one hit...

A new planet has been visualized in a protoplanetary disk around a star. It's the bright thing at about 4 o'clock. Star (PDS 70) is blocked out. Science magazine news article here.

So I'm attempting to write a scientifically accurate story and i need some help with the planets characteristics. I have a few things set up already and need some educated guesses and ideas for how the rest will work. So to start with what i have: Planet name: Remvale Radius:~8370 miles Gravity...

I was watching a really bad Japanese sci-fi movie in which the writers employed a frequent plot device. The Earth had a twin planet opposite the sun which made it undetectable to earthlings. This, of course, would be possible if the Earth's orbit was a perfect circle, which it isn't. It is, of...

Homework Statement A planet is in an elliptical orbit around a star. Which of the following best represents the mechanical energy E_planet of just the planet and the mechanical energy Es_tar-planet of the star-planet system as functions of time for one complete orbit? Homework Equations...

The idea is that, if we take the rotating frame of the fluid-planet so that it is at rest, then the sum of gravity and the centrifugal force must be perpendicular to the surface. Take the planet to be rotating about the y-axis at a rate ω. By symmetry we only need to work in 2 dimensions. So...

In solar system, we have sun and planets revolving around it. We have satellites orbiting around some of planets. Are all of these are same thing, just differentiated on the basis of size and nuclear processes occurring inside them? I mean, if nuclear processes occurring inside their core its a...

Information Given:Zero, a hypothetical planet, has a mass of 4.2 x 1023 kg, a radius of 2.8 x 106 m, and no atmosphere. A 10 kg space probe is to be launched vertically from its surface. Question: (a) If the probe is launched with an initial kinetic energy of 5.0 x 107 J, what will be its...

can two planets share the same orbit

A rocky Earth like exoplanet drifts into our solar system and will collide with Earth. It is 3 times the mass and diameter of Earth. We build a spacecraft to drill into the core of the Earth prior to the impact. Assume our craft can withstand 'infinite' pressure and temperature and is...

The next questions will be in english and spanish, since my birth language is spanish I may be mistaken in a few english words. --------------------------------------------------------------------------------------------------------------------------------------------- Spanish Debo advertir que...

Homework Statement A planet has a gaseous atmosphere with a density of 0.1 g/cm³. The planet itself completely consists of liquid methane with a density of 0.4 g/cm³ and has a radius of 3800 km. A test balloon is dropped onto this planet, which consists of a helium spherical balloon (1 m³, mass...

Homework Statement You are on a deep space mission to search for Earth-like planets. Your crew locates a possible planet and with scanners finds the radius to be 7.5 x 106 m. A team lands on the surface. There, they hang a 1.0 kg mass from a spring scale. It reads 8.5 N. Determine the mass of...

Hello everyone :) I have a question.Is it possible for life to exist in other planets without oxygen and water? I mean just because we need it to survive here on Earth.It doesn’t mean all planets need it to support life as well.

Homework Statement The dwarf planet Pluto orbits very ellipticaly... Pluto's nearest (perihelion) and farthest (apihelion) distances from the Sun are 30 AU and 50 AU, respectively. (One AU or Astronomical Unit=the mean distance from the center of the Earth to Astronomical Unit = the mean...