Planet Definition and 812 Threads

I always wondered this question i tried to ask my teachers but i keep forgetting so DOES the gravity of a planet determines its Density?

Homework Statement Calculate orbital radius of planet X using the given variables of its star: T=500 K, radius R=0.1 x Sun's radius, mass M=0.5 x Sun's mass and also its receives the same flux as the Earth receives from the Sun. I forgot to mention also that the orbit is circular, so the...

Contrary to what the article above states, before this discovery was made 90377 Sedna (2003 VB12) was the furthest trans-Neptunian dwarf planet in our solar system with Semi-Major Axis of 506 AU, and an Aphelion estimated to be ≈937 AU. The 103 AU distance the above article gives for V774104 is...

Homework Statement Hi! I would need a little help with the following problem: We have found a new planet with density ρ and radius R, and drill a hole to its center. Then accidentally, one person falls into the hole. What is his velocity when reaching the bottom (the center of the planet)...

Homework Statement Stellar mass 3.8 x 10^30 kg Star's orbital speed: 90 m/s Planet's orbital speed: 95,000 m/s Whats the mass of the planet in kilograms [/B]Homework EquationsThe Attempt at a Solution

Homework Statement Plaskett’s binary system consists of two stars that revolve in a circular orbit about a center of mass midway between them. This statement implies that the masses of the two stars are equal. Assume the orbital speed of each star is 220 km/s and the orbital period of each is...

Homework Statement How would you calculate the length of a year in Earth years on a hypothetical planet? (given the mass + radius of the planet) I understand Kelper's law is used somehow, but is orbital velocity needed?

Homework Statement On a certain planet, which is perfectly spherically symmetric, the free-fall acceleration has magnitude g = g0 at the North Pole and g = λ g0 at the equator (lambda is between zero and 1). Find g as a function of theta, the colatitude angle. Homework Equations \vec{g} =...

I'm using Chaisson'/McMillan's "Astronomy, a Beginner's Guide to the Universe"/7th Edition In Chapter 7, it describes the gas giants, and says that Jupiter, Uranus, and Neptune all have "86% Hydrogen, 14% Helium" in their atmospheres, while Saturn has about 92% hydrogen, and 7% Helium, in its...

Ahoy - so this is a rather multi-faceted question, but I need it properly answered for a creative project of mine. I could think of no better place to ask it, so forgive me if it's misplaced. I have on paper before me a fictional planet that does not rotate. It's general shape is a truncated...

Homework Statement An astronaut on a strange planet finds that he can jump a maximum horizontal distance of 30m if his initial speed is 9m/s. What is the acceleration of gravity on the planet? Homework Equations Vf^2=Vi^2+2a(Xf-Xi) The Attempt at a Solution I used the formula mentioned...

Hi all; Here's the sit: I'm writing a novel which involves colonization of other systems. I want to have a weirdo planet (thus the title) and I decided on a planet that doesn't quite complete a rotation. There's a thread here...

1. The trajectory of a rock thrown from a height with an initial speed of 20.9 m/s is shown in the figure below. Evaluate the magnitude of the gravitational field at the surface of the planet. The planet has no atmosphere...

I can't think of an instance of this in science fiction, but then I do not have the broadest knowledge of the field, so I could have missed something obvious to everyone else. I wonder, though, could a planet form at the center of mass of a binary star system or be captured there, and could...

I have reasoned that if i go by the assumption that i am here and the universe is as it is, the only things i can really understand are gravity, time and the study of nature (feel free to disagree) What happens at the time of death will be a topic for debate long after i have reached that point...

(Moderators note: moved from technical forums, does not use template) How would someone approach this problem? Find mass in kg of spherical planet if: -71.11% of surface is covered by oceans - avg depth of oceans is 12.83 furlongs -avg density of water is 1.030 g/mL -avg radius of planet is...

Why is the normal reaction of an object circulating a planet, equals to the gravitational force minus the centripetal force? I thought both gravitational force and centripetal force are directed towards the centre of the circular path i.e. in the same direction, therefore having, normal reaction...

That, anyway, is the headline in today's news, regarding the interesting discovery announced by NASA overnight of the planet dubbed Kepler-452b. As I understand it, the properties of the planet are inferred from spectral analysis of its effects on the light from the star which it orbits...

Setting info - take it as granted. Strategy - treat it as an open issue, if you see an alternative solution, please suggest it. Setting - natural conditions Planet to defend - Earthlike, tidal locked around red dwarf, water world, cold, 3 atm Main weakness point - gates - that allow...

Hello, I think it was Kurt Gödel who asked this while taking about time. The age of the universe and its size, is whatever it is for us because we are moving at a specific speed relative to light? If that is true, then a consciousness living on a planet moving at triple the speed of Earth...

What could you tell me about humans exploring this planet? Would it be feasible? Or would it be far too dangerous? What would be the biggest problem here? I am assuming the star class means it gives off a fairly high amount of radiation. Btw TY is "Earth years", "R" is x Earth radius, etc.

How did Kepler derive his laws of Planetary Motion without knowing about Newton's law of gravitation? Specifically, the first law of planetary motion which says that planets follow elliptical paths - how did he figure that out without the knowledge of the gravitational pull of the sun? Was it...

Ok, hear me out, I have a terrestrial planet that has mostly a thick atmosphere. The clouds absorb most of the sunlight, therefore barely anything gets through (similar to Venus). There are, however, certain "spots" or "safe zones", so to say, that are habitable for people to live in. There are...

I saw an explanation for why Jupiter has a slower tangential velocity in its orbit compared to inner planets and it stated: "Remember that by Kepler’s second law, the planets each sweep-out the same area in the same amount of time. The outer planets’ elliptical orbits are considerably larger...

I was doing some research on the findings of the Kepler space telescope this morning. I noticed that some of the stars it has found are quite small, and some of the planets in other systems are quite large. Is it theoretically possible for there to be a situation somewhere in the universe where...

And what would we bring? Assuming large space ship. What would be most difficult to rebuild on this new world? I am mostly talking about tools and possibly whole factories (or small versions). Also what industries would be most difficult to rebuild? Working on a game where you could do just...

1. Problem A rocket has landed on Planet X, which has half the radius of Earth. An astronaut onboard the rocket weighs twice as much on Planet X as on Earth. If the escape velocity for the rocket taking off from Earth is v , then its escape velocity on Planet X is a) 2 v b) (√2)v c) v d) v/2 e)...

Homework Statement Find the surface temperature of a small planet having circular orbit around the sun with time period T,assuming sun and planet to be black bodies. Take radius of sun = R, its mass = M and its surface temperature as ##\theta_0##. Homework Equations ##P=eA\sigma T^4## Total...

Homework Statement Hi there, I wish to use Newton's Laws in conjunction with Euler's Method to model the motion of a planet around a star.Homework Equations 2nd Law F = m*a Law of Universal Gravitation F = -G*M1*M2/r^2 The Attempt at a Solution [/B] First I combined the two laws above...

Homework Statement A terrestrial creature with mass m = 100kg to is standing on a planet the same size as our moon 1.) what is the gravitational acceleration on the surface of this planet ? Ag = GM/R^2 = 1.63 m/s 2.) work required to take creature off of planets surface and into space ...

Homework Statement A 26 year-old biologist makes a trip to study alien life forms in a distant planet 10 light-years away. The round trip including a stay of 1 year in the distance planet takes 21.5 years according to the clock on earth. The biologist’s son is 3 year-old when she left. Assume...

Homework Statement How much would a 1 kg mass weigh on the surface of a very dense planet with the same mass as Earth, but 1/2 Earth's radius? Homework Equations Eg(universe) = -G[(m1m2)/d^2] Earth's Radius = 3,959 mi Earth's mass = 5.97E24 kg The Attempt at a Solution If I plugged in those...

1. Asking because the answer I got seems too simple...a planet of mass m moves in an elliptical orbit about the sun. The minimum and maximum distances of the planet from the sun are called the perihelion and aphelion respectively. If the speed of the planet at p is vp, what is its speed at a...

Homework Statement [/B] 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 Rp. An object is located a distance Rfrom the center of the planet, where R<Rp. (The object is located inside of the planet.) Find a...

According to the concept: when a planet revolves around a star, and when both the bodies move in circular orbits due to the interaction between each other, both the bodies can be replaced by a single body of mass ##\mu## revolving in a circular orbit of radius equal to the distance between both...

Hi. I'm just a hobbier of astronomy and have a question about elliptical orbit. In Before, I had calculated the elipse of a planet successfully. In this case, I wonder that can calculate velocity(red vector) using orbit time(or position on elipse). Let me assume that we know orbit's semi-major...

Would an Earth-like planet while getting a tidal lock, get it influenced by landscape of surface? So that the most stable state would be to have a continent on the center of the side close to its star and the other on the exactly opposite side? Or maybe because of hydrostatic equilibrium such...

Homework Statement Suppose that an asteroid traveling straight toward the center of the Earth were to collide with our planet at the equator and bury itself just below the surface. What would have to be the mass of this asteroid, in terms of the Earth's mass M , for the day to become 26.0%...

Since most planets in the earliest stages of formation are very hot and fluid, why is it that we find on Earth areas where there are substantial deposits of heavier elements - gold, uranium, etc in the crust? Intuition suggests that these relatively rare elements would become widely dispersed...

I understand that it's possible to calculate the age of terrestial planets through radioactive dating their soil. However, the gas planets present a different challenge since we cannot currently land on them. Any ideas on how to calculate their ages in a different manner?

Homework Statement An object is located a distance d above the surface of a large planet of radius r. At this position, its true weight is one percent (1.000 %) less than its true weight on the surface. What is the ratio of d/r? Homework EquationsThe Attempt at a Solution so if something...

Hey, sorry if this is not the right section to post in, the topic is a bit ambiguous. I've generated a set of coordinate points for the orbit of Mercury (3d cartesian) and now I want to fit an ellipse through it so I can get an accurate estimate of the location of the perihelion. I am using...

I made a brain storming, but hope that someone would be able to point out what I may have missed out. Assumptions - atmospheric pressure is 3 atm, but molar concentration of oxygen is comparable to earth. The rest is mostly nitrogen. (there are a few more assumptions like tidal lock, a bit lower...

I was wondering if anyone would help me get my hands on some telescope data and images of exoplanets. I know they must exist somewhere in databases on the internet, but I haven't been able to find them myself. It would be great if one of you could show me where I could get them or even if you...

About: As a project, I'm trying to solve for the approximate radius and mass of a approximately earth-sized planet, Mann, from Interstellar. According to what was provided, g = 7.84m/s2 The solid part of the planet is composed of a honeycomb of rock and ice The space inside the honeycomb is...

The size of the shift (Redshift or Blue shift) combined with measurement of the period of orbit tells us how massive an object is. How? How can we know the mass of a planet using redshift or blue shift?

I kind of have a stupid question. How much more massive would the Earth have to be for the average person to weigh about 50 more pounds? How much bigger could the Earth's diameter be? Thanks.

Idea is a cold planet with dense atmosphere (10 atm) where human can survive, while a liquid carbon dioxide would be possible. As the main component of atmosphere I think about neon, because it should not cause nitrogen narcosis: http://en.wikipedia.org/wiki/Nitrogen_narcosis#Causes...

How can I quantify the energy on the planet gear of a planetary gear set? My thoughts are: All the energy that goes through a planetary gear set goes through the planet gear. This energy can be quantified as power with torque and rpm relative to the axis of the planet gear. Thanks John D

Homework Statement A stone is thrown horizontally from a cliff on a different planet with a speed of 10 m/s. The cliff has height 200m, and takes 4 s to hit the ground. Assume no air friction. What is the acceleration due to gravity on this planet. Homework Equations Δy = v0t + 1/2 at2 The...